Fix clang-tidy check readability-implicit-bool-cast.

47 files changed, 479 insertions, 475 deletions

diff --git a/src/net/eathena/adminhandler.cpp b/src/net/eathena/adminhandler.cpp
index e063f2f01..ac15da627 100644
--- a/src/net/eathena/adminhandler.cpp
+++ b/src/net/eathena/adminhandler.cpp
@@ -112,7 +112,7 @@ void AdminHandler::mute(const Being *const being,
                         const int type,
                         const int limit) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_ADMIN_MUTE);
@@ -129,7 +129,7 @@ void AdminHandler::muteName(const std::string &name) const
 
 void AdminHandler::requestLogin(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_ADMIN_ID_TO_LOGIN);
@@ -147,7 +147,7 @@ void AdminHandler::setTileType(const int x, const int y,
 
 void AdminHandler::unequipAll(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_ADMIN_UNEQUIP_ALL);
diff --git a/src/net/eathena/auctionhandler.cpp b/src/net/eathena/auctionhandler.cpp
index 3ccdfa7c1..84b7c6b0d 100644
--- a/src/net/eathena/auctionhandler.cpp
+++ b/src/net/eathena/auctionhandler.cpp
@@ -48,7 +48,7 @@ void AuctionHandler::cancelReg() const
 void AuctionHandler::setItem(const Item *const item,
                              const int amount) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
     createOutPacket(CMSG_AUCTION_SET_ITEM);
     outMsg.writeInt16(CAST_S16(
diff --git a/src/net/eathena/bankrecv.cpp b/src/net/eathena/bankrecv.cpp
index 0ac21e871..9f566d5a4 100644
--- a/src/net/eathena/bankrecv.cpp
+++ b/src/net/eathena/bankrecv.cpp
@@ -46,7 +46,7 @@ void BankRecv::processBankDeposit(Net::MessageIn &msg)
     const int money = CAST_S32(msg.readInt64("money"));
     msg.readInt32("balance");
     BankListener::distributeEvent(money);
-    if (reason)
+    if (reason != 0)
         NotifyManager::notify(NotifyTypes::BANK_DEPOSIT_FAILED);
 }
 
@@ -56,7 +56,7 @@ void BankRecv::processBankWithdraw(Net::MessageIn &msg)
     const int money = CAST_S32(msg.readInt64("money"));
     msg.readInt32("balance");
     BankListener::distributeEvent(money);
-    if (reason)
+    if (reason != 0)
         NotifyManager::notify(NotifyTypes::BANK_WITHDRAW_FAILED);
 }
 
diff --git a/src/net/eathena/battlegroundrecv.cpp b/src/net/eathena/battlegroundrecv.cpp
index 61ed702fa..2aaab9294 100644
--- a/src/net/eathena/battlegroundrecv.cpp
+++ b/src/net/eathena/battlegroundrecv.cpp
@@ -48,7 +48,7 @@ void BattleGroundRecv::processBattleEmblem2(Net::MessageIn &msg)
     const int teamId = msg.readInt16("team id");
 
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setTeamId(CAST_U16(teamId));
 }
 
diff --git a/src/net/eathena/beinghandler.cpp b/src/net/eathena/beinghandler.cpp
index 79e37e1cf..632485e7d 100644
--- a/src/net/eathena/beinghandler.cpp
+++ b/src/net/eathena/beinghandler.cpp
@@ -54,7 +54,7 @@ void BeingHandler::requestNameById(const BeingId id) const
 
 void BeingHandler::undress(Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
     being->unSetSprite(SPRITE_WEAPON);
     being->unSetSprite(SPRITE_HEAD_BOTTOM);
@@ -84,7 +84,7 @@ void BeingHandler::requestRanks(const RankT rank) const
 
 void BeingHandler::viewPlayerEquipment(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_PLAYER_VIEW_EQUIPMENT);
diff --git a/src/net/eathena/beingrecv.cpp b/src/net/eathena/beingrecv.cpp
index 1e9e56661..41fe73f39 100644
--- a/src/net/eathena/beingrecv.cpp
+++ b/src/net/eathena/beingrecv.cpp
@@ -72,7 +72,7 @@ namespace EAthena
 
 void BeingRecv::processBeingChangeLook2(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     Being *const dstBeing = actorManager->findBeing(
@@ -84,7 +84,7 @@ void BeingRecv::processBeingChangeLook2(Net::MessageIn &msg)
     if (type != 2)
         id2 = 1;
 
-    if (!localPlayer || !dstBeing)
+    if ((localPlayer == nullptr) || (dstBeing == nullptr))
         return;
 
     processBeingChangeLookContinue(msg, dstBeing, type, id, id2, nullptr);
@@ -95,7 +95,7 @@ void BeingRecv::processBeingChangeLookCards(Net::MessageIn &msg)
     Being *dstBeing = nullptr;
     int cards[maxCards];
 
-    if (!actorManager)
+    if (actorManager == nullptr)
     {   // here can be look from char server
         Net::Characters &chars = Net::CharServerHandler::mCharacters;
         const BeingId id = msg.readBeingId("being id");
@@ -103,7 +103,8 @@ void BeingRecv::processBeingChangeLookCards(Net::MessageIn &msg)
         FOR_EACH (Net::Characters::iterator, it, chars)
         {
             const Net::Character *const character = *it;
-            if (character->dummy && character->dummy->getId() == id)
+            if (character->dummy != nullptr &&
+                character->dummy->getId() == id)
             {
                 dstBeing = character->dummy;
                 break;
@@ -126,7 +127,7 @@ void BeingRecv::processBeingChangeLookCards(Net::MessageIn &msg)
     for (int f = 0; f < maxCards; f ++)
         cards[f] = msg.readUInt16("card");
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     processBeingChangeLookContinue(msg, dstBeing, type, id, id2, &cards[0]);
@@ -163,21 +164,21 @@ void BeingRecv::processBeingChangeLookContinue(const Net::MessageIn &msg,
             dstBeing->setWeaponId(id);
             dstBeing->setSpriteId(SPRITE_FLOOR,
                 id2);
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_FLOOR);
             break;
         case 3:  // LOOK_HEAD_BOTTOM
             dstBeing->setSpriteCards(SPRITE_WEAPON,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_WEAPON);
             break;
         case 4:  // LOOK_HEAD_TOP Change upper headgear for eAthena, hat for us
             dstBeing->setSpriteCards(SPRITE_CLOTHES_COLOR,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_CLOTHES_COLOR);
             break;
         case 5:  // LOOK_HEAD_MID Change middle headgear for eathena,
@@ -185,7 +186,7 @@ void BeingRecv::processBeingChangeLookContinue(const Net::MessageIn &msg,
             dstBeing->setSpriteCards(SPRITE_HEAD_BOTTOM,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_HEAD_BOTTOM);
             break;
         case 6:  // eAthena LOOK_HAIR_COLOR
@@ -202,84 +203,84 @@ void BeingRecv::processBeingChangeLookContinue(const Net::MessageIn &msg,
             dstBeing->setSpriteCards(SPRITE_FLOOR,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_FLOOR);
             break;
         case 9:  // eAthena LOOK_SHOES
             dstBeing->setSpriteCards(SPRITE_HAIR,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_HAIR);
             break;
         case 10:  // LOOK_GLOVES
             dstBeing->setSpriteCards(SPRITE_SHOES,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_SHOES);
             break;
         case 11:  // LOOK_FLOOR
             dstBeing->setSpriteCards(SPRITE_SHIELD,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_SHIELD);
             break;
         case 12:  // LOOK_ROBE
             dstBeing->setSpriteCards(SPRITE_HEAD_TOP,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_HEAD_TOP);
             break;
         case 13:  // COSTUME_HEAD_TOP
             dstBeing->setSpriteCards(SPRITE_HEAD_MID,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_HEAD_MID);
             break;
         case 14:  // COSTUME_HEAD_MID
             dstBeing->setSpriteCards(SPRITE_ROBE,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_ROBE);
             break;
         case 15:  // COSTUME_HEAD_LOW
             dstBeing->setSpriteCards(SPRITE_EVOL2,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_EVOL2);
             break;
         case 16:  // COSTUME_GARMENT
             dstBeing->setSpriteCards(SPRITE_EVOL3,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_EVOL3);
             break;
         case 17:  // ARMOR
             dstBeing->setSpriteCards(SPRITE_EVOL4,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_EVOL4);
             break;
         case 18:
             dstBeing->setSpriteCards(SPRITE_EVOL5,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_EVOL5);
             break;
         case 19:
             dstBeing->setSpriteCards(SPRITE_EVOL6,
                 id,
                 CardsList(cards));
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->imitateOutfit(dstBeing, SPRITE_EVOL6);
             break;
         default:
@@ -290,7 +291,7 @@ void BeingRecv::processBeingChangeLookContinue(const Net::MessageIn &msg,
 
 void BeingRecv::processBeingVisible(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     // need set type based on id
@@ -326,7 +327,7 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
 
     Being *dstBeing = actorManager->findBeing(id);
 
-    if (dstBeing && dstBeing->getType() == ActorType::Monster
+    if ((dstBeing != nullptr) && dstBeing->getType() == ActorType::Monster
         && !dstBeing->isAlive())
     {
         actorManager->destroy(dstBeing);
@@ -334,13 +335,13 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
         dstBeing = nullptr;
     }
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         if (actorManager->isBlocked(id) == true)
             return;
 
         dstBeing = createBeing2(msg, id, job, type);
-        if (!dstBeing)
+        if (dstBeing == nullptr)
             return;
     }
     else
@@ -370,7 +371,7 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
 
     dstBeing->setWalkSpeed(speed);
     dstBeing->setSubtype(fromInt(job, BeingTypeId), 0);
-    if (dstBeing->getType() == ActorType::Monster && localPlayer)
+    if (dstBeing->getType() == ActorType::Monster && (localPlayer != nullptr))
         localPlayer->checkNewName(dstBeing);
 
     const int hairStyle = msg.readInt16("hair style");
@@ -461,7 +462,7 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
     applyPlayerAction(msg, dstBeing, msg.readUInt8("action type"));
     dstBeing->setTileCoords(x, y);
 
-    if (job == 45 && socialWindow && outfitWindow)
+    if (job == 45 && (socialWindow != nullptr) && (outfitWindow != nullptr))
     {
         const int num = socialWindow->getPortalIndex(x, y);
         if (num >= 0)
@@ -478,7 +479,7 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
     dstBeing->setDirection(dir);
 
     const int level = CAST_S32(msg.readInt16("level"));
-    if (level)
+    if (level != 0)
         dstBeing->setLevel(level);
     if (msg.getVersion() >= 20080102)
         msg.readInt16("font");
@@ -521,7 +522,7 @@ void BeingRecv::processBeingVisible(Net::MessageIn &msg)
 
 void BeingRecv::processBeingMove(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     if (msg.getVersion() >= 20091103)
@@ -561,7 +562,7 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
 
     Being *dstBeing = actorManager->findBeing(id);
 
-    if (dstBeing && dstBeing->getType() == ActorType::Monster
+    if ((dstBeing != nullptr) && dstBeing->getType() == ActorType::Monster
         && !dstBeing->isAlive())
     {
         actorManager->destroy(dstBeing);
@@ -569,13 +570,13 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
         dstBeing = nullptr;
     }
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         if (actorManager->isBlocked(id) == true)
             return;
 
         dstBeing = createBeing2(msg, id, job, type);
-        if (!dstBeing)
+        if (dstBeing == nullptr)
             return;
     }
     else
@@ -597,7 +598,7 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
 
     dstBeing->setWalkSpeed(speed);
     dstBeing->setSubtype(fromInt(job, BeingTypeId), 0);
-    if (dstBeing->getType() == ActorType::Monster && localPlayer)
+    if (dstBeing->getType() == ActorType::Monster && (localPlayer != nullptr))
         localPlayer->checkNewName(dstBeing);
 
     const int hairStyle = msg.readInt16("hair style");
@@ -689,7 +690,7 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
     msg.readInt8("ys");
     dstBeing->setAction(BeingAction::STAND, 0);
     dstBeing->setTileCoords(srcX, srcY);
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->followMoveTo(dstBeing, srcX, srcY, dstX, dstY);
     if (serverFeatures->haveMove3())
         dstBeing->setCachedDestination(dstX, dstY);
@@ -714,11 +715,11 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
     {
         d = dstBeing->calcDirection(dstX, dstY);
     }
-    if (d && dstBeing->getDirection() != d)
+    if ((d != 0u) && dstBeing->getDirection() != d)
         dstBeing->setDirection(d);
 
     const int level = CAST_S32(msg.readInt16("level"));
-    if (level)
+    if (level != 0)
         dstBeing->setLevel(level);
     if (msg.getVersion() >= 20080102)
         msg.readInt16("font");
@@ -759,7 +760,7 @@ void BeingRecv::processBeingMove(Net::MessageIn &msg)
 
 void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     // need get type from id
@@ -792,7 +793,7 @@ void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
 
     Being *dstBeing = actorManager->findBeing(id);
 
-    if (dstBeing && dstBeing->getType() == ActorType::Monster
+    if ((dstBeing != nullptr) && dstBeing->getType() == ActorType::Monster
         && !dstBeing->isAlive())
     {
         actorManager->destroy(dstBeing);
@@ -800,13 +801,13 @@ void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
         dstBeing = nullptr;
     }
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         if (actorManager->isBlocked(id) == true)
             return;
 
         dstBeing = createBeing2(msg, id, job, type);
-        if (!dstBeing)
+        if (dstBeing == nullptr)
             return;
     }
     else
@@ -828,7 +829,7 @@ void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
 
     dstBeing->setWalkSpeed(speed);
     dstBeing->setSubtype(fromInt(job, BeingTypeId), 0);
-    if (dstBeing->getType() == ActorType::Monster && localPlayer)
+    if (dstBeing->getType() == ActorType::Monster && (localPlayer != nullptr))
         localPlayer->checkNewName(dstBeing);
 
     const int hairStyle = msg.readInt16("hair style");
@@ -916,7 +917,7 @@ void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
     msg.readInt8("ys");
     dstBeing->setTileCoords(x, y);
 
-    if (job == 45 && socialWindow && outfitWindow)
+    if (job == 45 && (socialWindow != nullptr) && (outfitWindow != nullptr))
     {
         const int num = socialWindow->getPortalIndex(x, y);
         if (num >= 0)
@@ -933,7 +934,7 @@ void BeingRecv::processBeingSpawn(Net::MessageIn &msg)
     dstBeing->setDirection(dir);
 
     const int level = CAST_S32(msg.readInt16("level"));
-    if (level)
+    if (level != 0)
         dstBeing->setLevel(level);
     if (msg.getVersion() >= 20080102)
         msg.readInt16("font");
@@ -982,10 +983,10 @@ void BeingRecv::processMapTypeProperty(Net::MessageIn &msg)
         MapTypeProperty2 props;
         props.data = CAST_U32(flags);
         const Game *const game = Game::instance();
-        if (!game)
+        if (game == nullptr)
             return;
         Map *const map = game->getCurrentMap();
-        if (!map)
+        if (map == nullptr)
             return;
         map->setPvpMode(props.bits.party | (props.bits.guild * 2));
     }
@@ -1058,7 +1059,7 @@ void BeingRecv::processSkillCastingContinue(Net::MessageIn &msg,
                                             const SkillType2::SkillType2 inf2,
                                             const int castTime)
 {
-    if (!effectManager)
+    if (effectManager == nullptr)
         return;
 
     if (srcId == BeingId_zero)
@@ -1070,10 +1071,10 @@ void BeingRecv::processSkillCastingContinue(Net::MessageIn &msg,
     if (dstId != BeingId_zero)
     {   // being to being
         Being *const dstBeing = actorManager->findBeing(dstId);
-        if (srcBeing)
+        if (srcBeing != nullptr)
         {
             srcBeing->handleSkillCasting(dstBeing, skillId, skillLevel);
-            if (dstBeing)
+            if (dstBeing != nullptr)
             {
                 srcBeing->addCast(dstBeing->getTileX(),
                     dstBeing->getTileY(),
@@ -1086,13 +1087,13 @@ void BeingRecv::processSkillCastingContinue(Net::MessageIn &msg,
     }
     else if (dstX != 0 || dstY != 0)
     {   // being to position
-        if (srcBeing)
+        if (srcBeing != nullptr)
             srcBeing->setAction(BeingAction::CAST, skillId);
         skillDialog->playCastingDstTileEffect(skillId,
             skillLevel,
             dstX, dstY,
             castTime);
-        if (srcBeing)
+        if (srcBeing != nullptr)
         {
             srcBeing->addCast(dstX, dstY,
                 skillId,
@@ -1101,7 +1102,7 @@ void BeingRecv::processSkillCastingContinue(Net::MessageIn &msg,
                 castTime / MILLISECONDS_IN_A_TICK);
         }
     }
-    if (localPlayer &&
+    if ((localPlayer != nullptr) &&
         srcBeing == localPlayer &&
         (inf2 & SkillType2::FreeCastAny) == 0)
     {
@@ -1112,7 +1113,7 @@ void BeingRecv::processSkillCastingContinue(Net::MessageIn &msg,
 void BeingRecv::processBeingStatusChange(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingStatusChange")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingStatusChange")
         return;
@@ -1137,7 +1138,7 @@ void BeingRecv::processBeingStatusChange(Net::MessageIn &msg)
         IsStart_false : IsStart_true;
 
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setStatusEffect(status, flag, start);
     BLOCK_END("BeingRecv::processBeingStatusChange")
 }
@@ -1145,7 +1146,7 @@ void BeingRecv::processBeingStatusChange(Net::MessageIn &msg)
 void BeingRecv::processBeingMove2(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingMove2")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingMove2")
         return;
@@ -1170,14 +1171,14 @@ void BeingRecv::processBeingMove2(Net::MessageIn &msg)
       * we'll just pretend the packet didn't happen
       */
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingMove2")
         return;
     }
 
     dstBeing->setTileCoords(srcX, srcY);
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->followMoveTo(dstBeing, srcX, srcY, dstX, dstY);
     if (serverFeatures->haveMove3())
         dstBeing->setCachedDestination(dstX, dstY);
@@ -1191,7 +1192,7 @@ void BeingRecv::processBeingMove2(Net::MessageIn &msg)
 void BeingRecv::processBeingAction2(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingAction2")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingAction2")
         return;
@@ -1231,16 +1232,16 @@ void BeingRecv::processBeingAction2(Net::MessageIn &msg)
         case AttackType::SPLASH:
         case AttackType::SKILL:
         case AttackType::REPEATE:
-            if (srcBeing)
+            if (srcBeing != nullptr)
             {
-                if (srcSpeed && srcBeing->getType() == ActorType::Player)
+                if (srcSpeed != 0 && srcBeing->getType() == ActorType::Player)
                     srcBeing->setAttackDelay(srcSpeed);
                 // attackid=1, type
                 srcBeing->handleAttack(dstBeing, param1, 1);
                 if (srcBeing->getType() == ActorType::Player)
                     srcBeing->setAttackTime();
             }
-            if (dstBeing)
+            if (dstBeing != nullptr)
             {
                 // level not present, using 1
                 dstBeing->takeDamage(srcBeing, param1,
@@ -1255,26 +1256,26 @@ void BeingRecv::processBeingAction2(Net::MessageIn &msg)
             break;
 
         case AttackType::SIT:
-            if (srcBeing)
+            if (srcBeing != nullptr)
             {
                 srcBeing->setAction(BeingAction::SIT, 0);
                 if (srcBeing->getType() == ActorType::Player)
                 {
                     srcBeing->setMoveTime();
-                    if (localPlayer)
+                    if (localPlayer != nullptr)
                         localPlayer->imitateAction(srcBeing, BeingAction::SIT);
                 }
             }
             break;
 
         case AttackType::STAND:
-            if (srcBeing)
+            if (srcBeing != nullptr)
             {
                 srcBeing->setAction(BeingAction::STAND, 0);
                 if (srcBeing->getType() == ActorType::Player)
                 {
                     srcBeing->setMoveTime();
-                    if (localPlayer)
+                    if (localPlayer != nullptr)
                     {
                         localPlayer->imitateAction(srcBeing,
                             BeingAction::STAND);
@@ -1307,7 +1308,7 @@ void BeingRecv::processBeingHp(Net::MessageIn &msg)
         hp = msg.readInt16("hp");
         maxHP = msg.readInt16("max hp");
     }
-    if (dstBeing)
+    if (dstBeing != nullptr)
     {
         dstBeing->setHP(hp);
         dstBeing->setMaxHP(maxHP);
@@ -1320,7 +1321,7 @@ void BeingRecv::processMonsterHp(Net::MessageIn &msg)
         msg.readBeingId("monster id"));
     const int hp = msg.readInt32("hp");
     const int maxHP = msg.readInt32("max hp");
-    if (dstBeing)
+    if (dstBeing != nullptr)
     {
         dstBeing->setHP(hp);
         dstBeing->setMaxHP(maxHP);
@@ -1338,7 +1339,7 @@ void BeingRecv::processSkillAutoCast(Net::MessageIn &msg)
     msg.readString(24, "skill name");
     msg.readInt8("unused");
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         localPlayer->handleSkill(localPlayer, 0, id, level);
         localPlayer->takeDamage(localPlayer, 0, AttackType::SKILL, id, level);
@@ -1400,7 +1401,7 @@ void BeingRecv::processPkRanksList(Net::MessageIn &msg)
 void BeingRecv::processBeingChangeDirection(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingChangeDirection")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingChangeDirection")
         return;
@@ -1414,26 +1415,26 @@ void BeingRecv::processBeingChangeDirection(Net::MessageIn &msg)
     const uint8_t dir = Net::MessageIn::fromServerDirection(
         CAST_U8(msg.readUInt8("player direction") & 0x0FU));
 
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         BLOCK_END("BeingRecv::processBeingChangeDirection")
         return;
     }
 
     dstBeing->setDirection(dir);
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->imitateDirection(dstBeing, dir);
     BLOCK_END("BeingRecv::processBeingChangeDirection")
 }
 
 void BeingRecv::processBeingSpecialEffect(Net::MessageIn &msg)
 {
-    if (!effectManager || !actorManager)
+    if ((effectManager == nullptr) || (actorManager == nullptr))
         return;
 
     const BeingId id = msg.readBeingId("being id");
     Being *const being = actorManager->findBeing(id);
-    if (!being)
+    if (being == nullptr)
         return;
 
     const int effectType = msg.readInt32("effect type");
@@ -1443,7 +1444,7 @@ void BeingRecv::processBeingSpecialEffect(Net::MessageIn &msg)
 
     // +++ need dehard code effectType == 3
     if (effectType == 3 && being->getType() == ActorType::Player
-        && socialWindow)
+        && (socialWindow != nullptr))
     {   // reset received damage
         socialWindow->resetDamage(being->getName());
     }
@@ -1501,7 +1502,7 @@ void BeingRecv::processSkillEntry(Net::MessageIn &msg)
         id,
         job,
         BeingType::SKILL);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
     dstBeing->setAction(BeingAction::STAND, 0);
     dstBeing->setTileCoords(x, y);
@@ -1512,7 +1513,7 @@ void BeingRecv::processSkillEntry(Net::MessageIn &msg)
 void BeingRecv::processPlayerStatusChange(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processPlayerStop")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processPlayerStop")
         return;
@@ -1521,7 +1522,7 @@ void BeingRecv::processPlayerStatusChange(Net::MessageIn &msg)
     // Change in players' flags
     const BeingId id = msg.readBeingId("account id");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     const uint32_t opt1 = msg.readInt16("opt1");
@@ -1541,14 +1542,14 @@ void BeingRecv::processPlayerStatusChange(Net::MessageIn &msg)
 
 void BeingRecv::processPlayerStatusChange2(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     // look like this function unused on server
 
     const BeingId id = msg.readBeingId("account id");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     const uint32_t option = msg.readInt32("option");
@@ -1560,7 +1561,7 @@ void BeingRecv::processPlayerStatusChange2(Net::MessageIn &msg)
 void BeingRecv::processBeingResurrect(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingResurrect")
-    if (!actorManager || !localPlayer)
+    if ((actorManager == nullptr) || (localPlayer == nullptr))
     {
         BLOCK_END("BeingRecv::processBeingResurrect")
         return;
@@ -1571,7 +1572,7 @@ void BeingRecv::processBeingResurrect(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("being id");
     msg.readInt16("unused");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
     {
         DEBUGLOGSTR("insible player?");
         BLOCK_END("BeingRecv::processBeingResurrect")
@@ -1589,7 +1590,7 @@ void BeingRecv::processBeingResurrect(Net::MessageIn &msg)
 void BeingRecv::processPlayerGuilPartyInfo(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processPlayerGuilPartyInfo")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processPlayerGuilPartyInfo")
         return;
@@ -1599,7 +1600,7 @@ void BeingRecv::processPlayerGuilPartyInfo(Net::MessageIn &msg)
     const std::string name = msg.readString(24, "char name");
     actorManager->updateNameId(name, beingId);
     Being *const dstBeing = actorManager->findBeing(beingId);
-    if (dstBeing)
+    if (dstBeing != nullptr)
     {
         if (beingId == localPlayer->getId())
         {
@@ -1623,10 +1624,10 @@ void BeingRecv::processPlayerGuilPartyInfo(Net::MessageIn &msg)
 void BeingRecv::processBeingRemoveSkill(Net::MessageIn &msg)
 {
     const BeingId id = msg.readBeingId("skill unit id");
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
     Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
     actorManager->destroy(dstBeing);
 }
@@ -1659,7 +1660,7 @@ void BeingRecv::processBeingFakeName(Net::MessageIn &msg)
     msg.skip(3, "unused");
 
     Being *const dstBeing = createBeing2(msg, id, job, type);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
     dstBeing->setSubtype(fromInt(job, BeingTypeId), 0);
     dstBeing->setTileCoords(x, y);
@@ -1673,7 +1674,7 @@ void BeingRecv::processBeingStatUpdate1(Net::MessageIn &msg)
     const int value = msg.readInt32("value");
 
     Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     if (type != Sp::MANNER)
@@ -1687,7 +1688,7 @@ void BeingRecv::processBeingStatUpdate1(Net::MessageIn &msg)
 void BeingRecv::processBeingSelfEffect(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processBeingSelfEffect")
-    if (!effectManager || !actorManager)
+    if ((effectManager == nullptr) || (actorManager == nullptr))
     {
         BLOCK_END("BeingRecv::processBeingSelfEffect")
         return;
@@ -1695,7 +1696,7 @@ void BeingRecv::processBeingSelfEffect(Net::MessageIn &msg)
 
     const BeingId id = msg.readBeingId("being id");
     Being *const being = actorManager->findBeing(id);
-    if (!being)
+    if (being == nullptr)
     {
         DEBUGLOGSTR("insible player?");
         msg.readInt32("effect type");
@@ -1718,7 +1719,7 @@ void BeingRecv::processMobInfo(Net::MessageIn &msg)
     Being *const dstBeing = actorManager->findBeing(
         msg.readBeingId("monster id"));
     const int attackRange = msg.readInt32("range");
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setAttackRange(attackRange);
 }
 
@@ -1736,9 +1737,9 @@ void BeingRecv::processBeingAttrs(Net::MessageIn &msg)
     int language = -1;
     if (serverVersion >= 17)
         language = msg.readInt16("language");
-    if (dstBeing)
+    if (dstBeing != nullptr)
     {
-        if (gmLevel)
+        if (gmLevel != 0)
         {
             if (dstBeing == localPlayer)
                 localPlayer->setGMLevel(gmLevel);
@@ -1785,7 +1786,7 @@ void BeingRecv::processSpiritBalls(Net::MessageIn &msg)
     Being *const dstBeing = actorManager->findBeing(
         msg.readBeingId("being id"));
     const int balls = msg.readInt16("spirits amount");
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setSpiritBalls(balls);
 }
 
@@ -1819,13 +1820,13 @@ void BeingRecv::processBeingSlide(Net::MessageIn &msg)
         msg.readBeingId("being id"));
     const int x = msg.readInt16("x");
     const int y = msg.readInt16("y");
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
     if (localPlayer == dstBeing)
     {
         localPlayer->stopAttack();
         localPlayer->navigateClean();
-        if (viewport)
+        if (viewport != nullptr)
             viewport->returnCamera();
     }
 
@@ -1929,10 +1930,10 @@ void BeingRecv::processPvpSet(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("being id");
     const int rank = msg.readInt32("rank");
     msg.readInt32("num");
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         Being *const dstBeing = actorManager->findBeing(id);
-        if (dstBeing)
+        if (dstBeing != nullptr)
             dstBeing->setPvpRank(rank);
     }
     BLOCK_END("BeingRecv::processPvpSet")
@@ -1941,7 +1942,7 @@ void BeingRecv::processPvpSet(Net::MessageIn &msg)
 void BeingRecv::processNameResponse2(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processNameResponse2")
-    if (!actorManager || !localPlayer)
+    if ((actorManager == nullptr) || (localPlayer == nullptr))
     {
         BLOCK_END("BeingRecv::processNameResponse2")
         return;
@@ -1952,7 +1953,7 @@ void BeingRecv::processNameResponse2(Net::MessageIn &msg)
     const std::string str = msg.readString(len - 8, "name");
     actorManager->updateNameId(str, beingId);
     Being *const dstBeing = actorManager->findBeing(beingId);
-    if (dstBeing)
+    if (dstBeing != nullptr)
     {
         if (beingId == localPlayer->getId())
         {
@@ -1967,15 +1968,15 @@ void BeingRecv::processNameResponse2(Net::MessageIn &msg)
             if (dstBeing->getType() == ActorType::Player)
                 dstBeing->updateColors();
 
-            if (localPlayer)
+            if (localPlayer != nullptr)
             {
                 const Party *const party = localPlayer->getParty();
-                if (party && party->isMember(dstBeing->getId()))
+                if (party != nullptr && party->isMember(dstBeing->getId()))
                 {
                     PartyMember *const member = party->getMember(
                         dstBeing->getId());
 
-                    if (member)
+                    if (member != nullptr)
                         member->setName(dstBeing->getName());
                 }
                 localPlayer->checkNewName(dstBeing);
@@ -1990,7 +1991,7 @@ Being *BeingRecv::createBeing2(Net::MessageIn &msg,
                                const int32_t job,
                                const BeingTypeT beingType)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return nullptr;
 
     ActorTypeT type = ActorType::Unknown;
@@ -2041,7 +2042,7 @@ Being *BeingRecv::createBeing2(Net::MessageIn &msg,
     if (beingType == BeingType::MERSOL)
     {
         const MercenaryInfo *const info = PlayerInfo::getMercenary();
-        if (info && info->id == id)
+        if ((info != nullptr) && info->id == id)
             PlayerInfo::setMercenaryBeing(being);
     }
     else if (beingType == BeingType::PET)
@@ -2061,7 +2062,7 @@ void BeingRecv::processSolveCharName(Net::MessageIn &msg)
 {
     const int id = msg.readInt32("char id");
     const std::string name = msg.readString(24, "name");
-    if (actorManager)
+    if (actorManager != nullptr)
         actorManager->addChar(id, name);
 }
 
@@ -2077,7 +2078,7 @@ void BeingRecv::processGraffiti(Net::MessageIn &msg)
     const std::string text = msg.readString(80, "text");
 
     Being *const dstBeing = createBeing2(msg, id, job, BeingType::SKILL);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     dstBeing->setAction(BeingAction::STAND, 0);
@@ -2090,7 +2091,7 @@ void BeingRecv::processGraffiti(Net::MessageIn &msg)
 void BeingRecv::processSkillDamage(Net::MessageIn &msg)
 {
     BLOCK_START("BeingRecv::processSkillDamage")
-    if (!actorManager)
+    if (actorManager == nullptr)
     {
         BLOCK_END("BeingRecv::processSkillDamage")
         return;
@@ -2112,9 +2113,9 @@ void BeingRecv::processSkillDamage(Net::MessageIn &msg)
     const int level = msg.readInt16("skill level");
     msg.readInt16("div");
     msg.readUInt8("skill hit/type?");
-    if (srcBeing)
+    if (srcBeing != nullptr)
         srcBeing->handleSkill(dstBeing, param1, id, level);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->takeDamage(srcBeing, param1, AttackType::SKILL, id, level);
     BLOCK_END("BeingRecv::processSkillDamage")
 }
@@ -2138,7 +2139,7 @@ void BeingRecv::applyPlayerAction(Net::MessageIn &msg,
                                   Being *const being,
                                   const uint8_t type)
 {
-    if (!being)
+    if (being == nullptr)
         return;
     switch (type)
     {
diff --git a/src/net/eathena/buyingstorehandler.cpp b/src/net/eathena/buyingstorehandler.cpp
index 0cc551bdf..8bd3392a0 100644
--- a/src/net/eathena/buyingstorehandler.cpp
+++ b/src/net/eathena/buyingstorehandler.cpp
@@ -53,7 +53,7 @@ void BuyingStoreHandler::create(const std::string &name,
     createOutPacket(CMSG_BUYINGSTORE_CREATE);
     outMsg.writeInt16(CAST_S16(89 + items.size() * 8), "len");
     outMsg.writeInt32(maxMoney, "limit money");
-    outMsg.writeInt8(flag, "flag");
+    outMsg.writeInt8(static_cast<int8_t>(flag), "flag");
     outMsg.writeString(name, 80, "store name");
     FOR_EACH (std::vector<ShopItem*>::const_iterator, it, items)
     {
@@ -74,7 +74,7 @@ void BuyingStoreHandler::close() const
 
 void BuyingStoreHandler::open(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
     if (packetVersion < 20100420)
         return;
@@ -87,7 +87,7 @@ void BuyingStoreHandler::sell(const Being *const being,
                               const Item *const item,
                               const int amount) const
 {
-    if (!being || !item)
+    if ((being == nullptr) || (item == nullptr))
         return;
     if (packetVersion < 20100420)
         return;
diff --git a/src/net/eathena/buyingstorerecv.cpp b/src/net/eathena/buyingstorerecv.cpp
index 4f9188280..55c1624f9 100644
--- a/src/net/eathena/buyingstorerecv.cpp
+++ b/src/net/eathena/buyingstorerecv.cpp
@@ -96,7 +96,7 @@ void BuyingStoreRecv::processBuyingStoreShowBoard(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("owner id");
     const std::string shopName = msg.readString(80, "shop name");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setBuyBoard(shopName);
 }
 
@@ -104,7 +104,7 @@ void BuyingStoreRecv::processBuyingStoreHideBoard(Net::MessageIn &msg)
 {
     const BeingId id = msg.readBeingId("owner id");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setBuyBoard(std::string());
     if (dstBeing == localPlayer)
     {
@@ -122,7 +122,7 @@ void BuyingStoreRecv::processBuyingStoreItemsList(Net::MessageIn &msg)
     msg.readInt32("money limit");
 
     const Being *const dstBeing = actorManager->findBeing(id);
-    if (!dstBeing)
+    if (dstBeing == nullptr)
         return;
 
     SellDialog *const dialog = CREATEWIDGETR(BuyingStoreSellDialog,
@@ -138,10 +138,10 @@ void BuyingStoreRecv::processBuyingStoreItemsList(Net::MessageIn &msg)
             msg.readUInt8("item type"));
         const int itemId = msg.readInt16("item id");
 
-        if (!inv)
+        if (inv == nullptr)
             continue;
         const Item *const item = inv->findItem(itemId, ItemColor_one);
-        if (!item)
+        if (item == nullptr)
             continue;
         // +++ need add colors support
         dialog->addItem(itemId, itemType, ItemColor_one, amount, price);
@@ -211,14 +211,14 @@ void BuyingStoreRecv::processBuyingStoreReport(Net::MessageIn &msg)
 
 void BuyingStoreRecv::processBuyingStoreDeleteItem(Net::MessageIn &msg)
 {
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
     const int index = msg.readInt16("index") - INVENTORY_OFFSET;
     const int amount = msg.readInt16("amount");
     msg.readInt32("price");
 
-    if (inventory)
+    if (inventory != nullptr)
     {
         if (Item *const item = inventory->getItem(index))
         {
diff --git a/src/net/eathena/buysellrecv.cpp b/src/net/eathena/buysellrecv.cpp
index 4b111dee9..db2b6a607 100644
--- a/src/net/eathena/buysellrecv.cpp
+++ b/src/net/eathena/buysellrecv.cpp
@@ -61,7 +61,7 @@ void BuySellRecv::processNpcBuy(Net::MessageIn &msg)
     if (npcId != BeingTypeId_zero)
     {
         const BeingInfo *const info = NPCDB::get(npcId);
-        if (info)
+        if (info != nullptr)
             currency = info->getCurrency();
         else
             currency = DEFAULT_CURRENCY;
diff --git a/src/net/eathena/cashshophandler.cpp b/src/net/eathena/cashshophandler.cpp
index 7f3cf6ce8..40e23d3a5 100644
--- a/src/net/eathena/cashshophandler.cpp
+++ b/src/net/eathena/cashshophandler.cpp
@@ -70,7 +70,7 @@ void CashShopHandler::buyItems(const int points,
         const ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
         const ItemTypeT type = item->getType();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         if (type == ItemType::Weapon ||
             type == ItemType::Armor ||
@@ -96,7 +96,7 @@ void CashShopHandler::buyItems(const int points,
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         item->increaseQuantity(usedQuantity);
         item->increaseUsedQuantity(-usedQuantity);
diff --git a/src/net/eathena/cashshoprecv.cpp b/src/net/eathena/cashshoprecv.cpp
index deafbec28..796d2a211 100644
--- a/src/net/eathena/cashshoprecv.cpp
+++ b/src/net/eathena/cashshoprecv.cpp
@@ -64,7 +64,7 @@ void CashShopRecv::processCashShopOpen(Net::MessageIn &msg)
     if (npcId != BeingTypeId_zero)
     {
         const BeingInfo *const info = NPCDB::get(npcId);
-        if (info)
+        if (info != nullptr)
             currency = info->getCurrency();
         else
             currency = DEFAULT_CURRENCY;
diff --git a/src/net/eathena/charserverhandler.cpp b/src/net/eathena/charserverhandler.cpp
index 098cdf248..22fbe000a 100644
--- a/src/net/eathena/charserverhandler.cpp
+++ b/src/net/eathena/charserverhandler.cpp
@@ -61,7 +61,7 @@ CharServerHandler::CharServerHandler() :
 
 void CharServerHandler::chooseCharacter(Net::Character *const character) const
 {
-    if (!character)
+    if (character == nullptr)
         return;
 
     mSelectedCharacter = character;
@@ -140,7 +140,7 @@ void CharServerHandler::newCharacter(const std::string &name, const int slot,
 void CharServerHandler::deleteCharacter(Net::Character *const character,
                                         const std::string &email) const
 {
-    if (!character)
+    if (character == nullptr)
         return;
 
     mSelectedCharacter = character;
@@ -165,7 +165,7 @@ void CharServerHandler::connect() const
     const Token &token =
         static_cast<LoginHandler*>(loginHandler)->getToken();
 
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return;
 
     Network::mInstance->disconnect();
@@ -186,7 +186,7 @@ void CharServerHandler::setCharCreateDialog(CharCreateDialog *const window)
 {
     mCharCreateDialog = window;
 
-    if (!mCharCreateDialog)
+    if (mCharCreateDialog == nullptr)
         return;
 
     StringVect attributes;
diff --git a/src/net/eathena/charserverrecv.cpp b/src/net/eathena/charserverrecv.cpp
index 90e9618a1..fbeaf7f29 100644
--- a/src/net/eathena/charserverrecv.cpp
+++ b/src/net/eathena/charserverrecv.cpp
@@ -77,7 +77,7 @@ namespace CharServerRecv
 void CharServerRecv::readPlayerData(Net::MessageIn &msg,
                                     Net::Character *const character)
 {
-    if (!character)
+    if (character == nullptr)
         return;
 
     const Token &token =
@@ -202,7 +202,7 @@ void CharServerRecv::readPlayerData(Net::MessageIn &msg,
     if (packetVersion >= 20110928)
         msg.readInt32("slot change");
     if (packetVersion >= 20111025)
-        tempPlayer->setRename(msg.readInt32("rename (inverse)"));
+        tempPlayer->setRename(msg.readInt32("rename (inverse)") != 0);
     uint8_t gender = 99U;
     if (packetVersion >= 20141016)
         gender = CAST_U8(msg.readUInt8("gender"));
@@ -238,7 +238,7 @@ void CharServerRecv::processCharLogin(Net::MessageIn &msg)
         Net::Character *const character = new Net::Character;
         readPlayerData(msg, character);
         charServerHandler->mCharacters.push_back(character);
-        if (character->dummy)
+        if (character->dummy != nullptr)
         {
             logger->log("CharServer: Player: %s (%d)",
                 character->dummy->getName().c_str(), character->slot);
@@ -290,7 +290,7 @@ void CharServerRecv::processCharMapInfo(Net::MessageIn &restrict msg)
     charServerHandler->clear();
     charServerHandler->updateCharSelectDialog();
 
-    if (network)
+    if (network != nullptr)
         network->disconnect();
     client->setState(State::CONNECT_GAME);
     BLOCK_END("CharServerRecv::processCharMapInfo")
@@ -302,7 +302,7 @@ void CharServerRecv::processChangeMapServer(Net::MessageIn &msg)
     ServerInfo &server = mapServer;
     BLOCK_START("CharServerRecv::processChangeMapServer")
     const GameHandler *const gh = static_cast<GameHandler*>(gameHandler);
-    if (!gh || !network)
+    if ((gh == nullptr) || (network == nullptr))
     {
         BLOCK_END("CharServerRecv::processChangeMapServer")
         return;
@@ -323,7 +323,7 @@ void CharServerRecv::processChangeMapServer(Net::MessageIn &msg)
 
     network->disconnect();
     client->setState(State::CHANGE_MAP);
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         localPlayer->setTileCoords(x, y);
         localPlayer->setMap(nullptr);
@@ -374,7 +374,7 @@ void CharServerRecv::processCharCreate(Net::MessageIn &msg)
     charServerHandler->updateCharSelectDialog();
 
     // Close the character create dialog
-    if (charServerHandler->mCharCreateDialog)
+    if (charServerHandler->mCharCreateDialog != nullptr)
     {
         charServerHandler->mCharCreateDialog->scheduleDelete();
         charServerHandler->mCharCreateDialog = nullptr;
@@ -384,7 +384,7 @@ void CharServerRecv::processCharCreate(Net::MessageIn &msg)
 
 void CharServerRecv::processCharCheckRename(Net::MessageIn &msg)
 {
-    if (msg.readInt16("flag"))
+    if (msg.readInt16("flag") != 0)
     {
         createOutPacket(CMSG_CHAR_RENAME);
         outMsg.writeBeingId(mRenameId, "char id");
@@ -409,7 +409,7 @@ void CharServerRecv::processCharCheckRename(Net::MessageIn &msg)
 void CharServerRecv::processCharRename(Net::MessageIn &msg)
 {
     const int flag = msg.readInt16("flag");
-    if (!flag)
+    if (flag == 0)
     {
         charServerHandler->mCharSelectDialog->setName(
             mRenameId,
@@ -539,7 +539,7 @@ void CharServerRecv::processCharCharacters(Net::MessageIn &msg)
         Net::Character *const character = new Net::Character;
         readPlayerData(msg, character);
         charServerHandler->mCharacters.push_back(character);
-        if (character->dummy)
+        if (character->dummy != nullptr)
         {
             logger->log("CharServer: Player: %s (%d)",
                 character->dummy->getName().c_str(), character->slot);
diff --git a/src/net/eathena/chathandler.cpp b/src/net/eathena/chathandler.cpp
index ad779666c..f5f6760f1 100644
--- a/src/net/eathena/chathandler.cpp
+++ b/src/net/eathena/chathandler.cpp
@@ -53,7 +53,7 @@ ChatHandler::ChatHandler() :
 void ChatHandler::talk(const std::string &restrict text,
                        const std::string &restrict channel A_UNUSED) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const std::string mes = std::string(localPlayer->getName()).append(
@@ -230,7 +230,7 @@ void ChatHandler::createChatRoom(const std::string &title,
 
 void ChatHandler::battleTalk(const std::string &text) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const std::string mes = std::string(localPlayer->getName()).append(
@@ -253,7 +253,7 @@ void ChatHandler::battleTalk(const std::string &text) const
 void ChatHandler::joinChat(const ChatObject *const chat,
                            const std::string &password) const
 {
-    if (!chat)
+    if (chat == nullptr)
         return;
 
     createOutPacket(CMSG_CHAT_ROOM_JOIN);
diff --git a/src/net/eathena/chatrecv.cpp b/src/net/eathena/chatrecv.cpp
index 524b0a9f3..1aee777e9 100644
--- a/src/net/eathena/chatrecv.cpp
+++ b/src/net/eathena/chatrecv.cpp
@@ -201,7 +201,7 @@ void ChatRecv::processColorChat(Net::MessageIn &msg)
     if (findCutFirst(msg2, "You're now in the '#") && findCutLast(msg2, "'"))
     {
         const size_t idx = msg2.find("' channel for '");
-        if (idx != std::string::npos && chatWindow)
+        if (idx != std::string::npos && (chatWindow != nullptr))
         {
             chatWindow->addChannelTab(std::string("#").append(
                 msg2.substr(0, idx)), false);
@@ -244,7 +244,7 @@ void ChatRecv::processChatContinue(std::string chatMsg,
 {
     const std::string channel = extractChannelFromMessage(chatMsg);
     bool allow(true);
-    if (chatWindow)
+    if (chatWindow != nullptr)
     {
         allow = chatWindow->resortChatLog(chatMsg,
             own,
@@ -259,9 +259,9 @@ void ChatRecv::processChatContinue(std::string chatMsg,
 
     trim(chatMsg);
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
-        if ((chatWindow || Ea::ChatRecv::mShowMotd) && allow)
+        if (((chatWindow != nullptr) || Ea::ChatRecv::mShowMotd) && allow)
             localPlayer->setSpeech(chatMsg, GENERAL_CHANNEL);
     }
     BLOCK_END("ChatRecv::processChat")
@@ -282,7 +282,7 @@ void ChatRecv::processGmChat(Net::MessageIn &msg)
     if (!findCutFirst(chatMsg, "ssss"))
         findCutFirst(chatMsg, "eulb");
 
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->addGlobalMessage(chatMsg);
     BLOCK_END("ChatRecv::processChat")
 }
@@ -296,7 +296,7 @@ void ChatRecv::processGmChat2(Net::MessageIn &msg)
     msg.readInt16("font align");
     msg.readInt16("font y");
     const std::string chatMsg = msg.readRawString(chatMsgLength, "message");
-    if (chatWindow)
+    if (chatWindow != nullptr)
         chatWindow->addGlobalMessage(chatMsg);
 }
 
@@ -327,7 +327,7 @@ void ChatRecv::processWhisperResponse(Net::MessageIn &msg)
     const uint8_t type = msg.readUInt8("response");
     if (msg.getVersion() >= 20131223)
         msg.readInt32("unknown");
-    if (type == 1 && chatWindow)
+    if (type == 1 && (chatWindow != nullptr))
     {
         const std::string nick = Ea::ChatRecv::getLastWhisperNick();
         if (nick.size() > 1 && nick[0] == '#')
@@ -369,7 +369,7 @@ void ChatRecv::processChatDisplay(Net::MessageIn &msg)
     obj->update();
 
     Being *const dstBeing = actorManager->findBeing(obj->ownerId);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setChat(obj);
 }
 
@@ -387,13 +387,13 @@ void ChatRecv::processChatRoomJoinAck(Net::MessageIn &msg)
 
     const ChatObject *const oldChat = ChatObject::findById(id);
 
-    if (oldChat)
+    if (oldChat != nullptr)
         PlayerInfo::setRoomName(oldChat->title);
     else
         PlayerInfo::setRoomName(std::string());
     chatWindow->joinRoom(true);
     ChatObject *const obj = new ChatObject;
-    if (oldChat)
+    if (oldChat != nullptr)
     {
         obj->ownerId = oldChat->ownerId;
         obj->chatId = oldChat->chatId;
@@ -423,26 +423,26 @@ void ChatRecv::processChatRoomLeave(Net::MessageIn &msg)
             UNIMPLEMENTEDPACKETFIELD(status);
             break;
     }
-    if (localPlayer && name == localPlayer->getName())
+    if ((localPlayer != nullptr) && name == localPlayer->getName())
     {
-        if (chatWindow)
+        if (chatWindow != nullptr)
             chatWindow->joinRoom(false);
         PlayerInfo::setRoomName(std::string());
-        if (localPlayer)
+        if (localPlayer != nullptr)
             localPlayer->setChat(nullptr);
     }
     else
     {
         Being *const being = actorManager->findBeingByName(
             name, ActorType::Player);
-        if (being)
+        if (being != nullptr)
             being->setChat(nullptr);
     }
 }
 
 void ChatRecv::processJoinChannel(Net::MessageIn &msg)
 {
-    if (!chatWindow)
+    if (chatWindow == nullptr)
         return;
 
     const std::string channel = msg.readString(24, "channel name");
@@ -489,7 +489,7 @@ void ChatRecv::processWhisperContinue(const std::string &nick,
         if (player_relations.hasPermission(nick, PlayerRelation::WHISPER))
             chatWindow->addWhisper(nick, chatMsg);
     }
-    else if (localChatTab)
+    else if (localChatTab != nullptr)
     {
         localChatTab->chatLog(chatMsg, ChatMsgType::BY_SERVER);
     }
@@ -498,7 +498,7 @@ void ChatRecv::processWhisperContinue(const std::string &nick,
 
 void ChatRecv::processBeingChat(Net::MessageIn &msg)
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     BLOCK_START("ChatRecv::processBeingChat")
@@ -513,14 +513,14 @@ void ChatRecv::processBeingChat(Net::MessageIn &msg)
 
     std::string chatMsg = msg.readRawString(chatMsgLength, "message");
 
-    if (being && being->getType() == ActorType::Player)
+    if ((being != nullptr) && being->getType() == ActorType::Player)
         being->setTalkTime();
 
     const size_t pos = chatMsg.find(" : ", 0);
     std::string sender_name = ((pos == std::string::npos)
         ? "" : chatMsg.substr(0, pos));
 
-    if (being && sender_name != being->getName()
+    if ((being != nullptr) && sender_name != being->getName()
         && being->getType() == ActorType::Player)
     {
         if (!being->getName().empty())
@@ -537,8 +537,8 @@ void ChatRecv::processBeingChat(Net::MessageIn &msg)
     // We use getIgnorePlayer instead of ignoringPlayer here
     // because ignorePlayer' side effects are triggered
     // right below for Being::IGNORE_SPEECH_FLOAT.
-    if (player_relations.checkPermissionSilently(sender_name,
-        PlayerRelation::SPEECH_LOG) && chatWindow)
+    if ((player_relations.checkPermissionSilently(sender_name,
+        PlayerRelation::SPEECH_LOG) != 0u) && (chatWindow != nullptr))
     {
         allow = chatWindow->resortChatLog(
             removeColors(sender_name).append(" : ").append(chatMsg),
@@ -548,7 +548,7 @@ void ChatRecv::processBeingChat(Net::MessageIn &msg)
             TryRemoveColors_true);
     }
 
-    if (allow && being && player_relations.hasPermission(sender_name,
+    if (allow && (being != nullptr) && player_relations.hasPermission(sender_name,
         PlayerRelation::SPEECH_FLOAT))
     {
         being->setSpeech(chatMsg, GENERAL_CHANNEL);
@@ -632,7 +632,7 @@ void ChatRecv::processChatRoomAddMember(Net::MessageIn &msg)
 {
     msg.readInt16("users");
     const std::string name = msg.readString(24, "name");
-    if (!localChatTab)
+    if (localChatTab == nullptr)
         return;
     NotifyManager::notify(NotifyTypes::ROOM_JOINED, name);
 }
@@ -647,7 +647,7 @@ void ChatRecv::processChatRoomSettings(Net::MessageIn &msg)
     const uint8_t type = msg.readUInt8("type");
     const std::string &title = msg.readString(sz, "title");
     ChatObject *const chat = localPlayer->getChat();
-    if (chat && chat->chatId == chatId)
+    if ((chat != nullptr) && chat->chatId == chatId)
     {
         chat->ownerId = ownerId;
         chat->maxUsers = limit;
diff --git a/src/net/eathena/familyhandler.cpp b/src/net/eathena/familyhandler.cpp
index 02bd5b43b..1a71c086d 100644
--- a/src/net/eathena/familyhandler.cpp
+++ b/src/net/eathena/familyhandler.cpp
@@ -44,7 +44,7 @@ FamilyHandler::FamilyHandler() :
 
 void FamilyHandler::askForChild(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_FAMILY_ASK_FOR_CHILD);
diff --git a/src/net/eathena/familyrecv.cpp b/src/net/eathena/familyrecv.cpp
index 8b3ca1df9..f9f7b2fd8 100644
--- a/src/net/eathena/familyrecv.cpp
+++ b/src/net/eathena/familyrecv.cpp
@@ -51,7 +51,7 @@ namespace FamilyRecv
 
 void FamilyRecv::processAskForChild(Net::MessageIn &msg)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
     {
         mParent1 = msg.readBeingId("account id who ask");
         mParent2 = msg.readBeingId("acoount id for other parent");
@@ -62,10 +62,10 @@ void FamilyRecv::processAskForChild(Net::MessageIn &msg)
     mParent2 = msg.readBeingId("acoount id for other parent");
     const std::string name1 = msg.readString(24, "name who ask");
     const Party *const party = localPlayer->getParty();
-    if (party)
+    if (party != nullptr)
     {
         const PartyMember *const member = party->getMember(mParent2);
-        if (member)
+        if (member != nullptr)
         {
             const std::string name2 = member->getName();
             CREATEWIDGETV(confirmDlg, ConfirmDialog,
@@ -84,7 +84,7 @@ void FamilyRecv::processAskForChild(Net::MessageIn &msg)
 void FamilyRecv::processCallPartner(Net::MessageIn &msg)
 {
     const std::string name = msg.readString(24, "name");
-    if (localPlayer && name == localPlayer->getName())
+    if ((localPlayer != nullptr) && name == localPlayer->getName())
     {
         NotifyManager::notify(NotifyTypes::CALLED_PARTNER);
     }
diff --git a/src/net/eathena/gamehandler.cpp b/src/net/eathena/gamehandler.cpp
index 019640937..8a169de60 100644
--- a/src/net/eathena/gamehandler.cpp
+++ b/src/net/eathena/gamehandler.cpp
@@ -60,7 +60,7 @@ void GameHandler::mapLoadedEvent() const
 
 void GameHandler::connect() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return;
 
     Network::mInstance->connect(mapServer);
@@ -71,7 +71,7 @@ void GameHandler::connect() const
     if (client->getState() == State::CONNECT_GAME)
     {
         // Change the player's ID to the account ID to match what eAthena uses
-        if (localPlayer)
+        if (localPlayer != nullptr)
         {
             Ea::GameRecv::mCharID = localPlayer->getId();
             localPlayer->setId(token.account_ID);
@@ -98,14 +98,14 @@ void GameHandler::connect() const
 
 bool GameHandler::isConnected() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return false;
     return Network::mInstance->isConnected();
 }
 
 void GameHandler::disconnect() const
 {
-    if (Network::mInstance)
+    if (Network::mInstance != nullptr)
         Network::mInstance->disconnect();
 }
 
diff --git a/src/net/eathena/gamerecv.cpp b/src/net/eathena/gamerecv.cpp
index 865ed5820..00d2c4f9d 100644
--- a/src/net/eathena/gamerecv.cpp
+++ b/src/net/eathena/gamerecv.cpp
@@ -63,12 +63,12 @@ void GameRecv::processMapLogin(Net::MessageIn &msg)
     mLastHost &= 0xffffff;
 
     Network *const network = Network::mInstance;
-    if (network)
+    if (network != nullptr)
         network->pauseDispatch();
 
     // Switch now or we'll have problems
     client->setState(State::GAME);
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->setTileCoords(x, y);
 }
 
diff --git a/src/net/eathena/generalhandler.cpp b/src/net/eathena/generalhandler.cpp
index 9c09d86a4..cfe77bc09 100644
--- a/src/net/eathena/generalhandler.cpp
+++ b/src/net/eathena/generalhandler.cpp
@@ -129,7 +129,7 @@ void GeneralHandler::load() const
 
 void GeneralHandler::reload() const
 {
-    if (Network::mInstance)
+    if (Network::mInstance != nullptr)
         Network::mInstance->disconnect();
 
     static_cast<LoginHandler*>(mLoginHandler)->clearWorlds();
@@ -152,7 +152,7 @@ void GeneralHandler::unload() const
 
 void GeneralHandler::flushSend() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return;
 
     Network::mInstance->flush();
@@ -160,7 +160,7 @@ void GeneralHandler::flushSend() const
 
 void GeneralHandler::flushNetwork() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return;
 
     Network::mInstance->flush();
@@ -184,19 +184,19 @@ void GeneralHandler::flushNetwork() const
 
 void GeneralHandler::clearHandlers() const
 {
-    if (Network::mInstance)
+    if (Network::mInstance != nullptr)
         Network::mInstance->clearHandlers();
 }
 
 void GeneralHandler::gameStarted() const
 {
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->loadSkills();
 }
 
 void GeneralHandler::gameEnded() const
 {
-    if (socialWindow)
+    if (socialWindow != nullptr)
     {
         socialWindow->removeTab(taGuild);
         socialWindow->removeTab(Ea::taParty);
diff --git a/src/net/eathena/guildhandler.cpp b/src/net/eathena/guildhandler.cpp
index 3ea95b438..f2c90e874 100644
--- a/src/net/eathena/guildhandler.cpp
+++ b/src/net/eathena/guildhandler.cpp
@@ -75,12 +75,12 @@ void GuildHandler::create(const std::string &name) const
 
 void GuildHandler::invite(const std::string &name) const
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
 
     const Being *const being = actorManager->findBeingByName(
         name, ActorType::Player);
-    if (being)
+    if (being != nullptr)
     {
         createOutPacket(CMSG_GUILD_INVITE);
         outMsg.writeBeingId(being->getId(), "account id");
@@ -96,7 +96,7 @@ void GuildHandler::invite(const std::string &name) const
 
 void GuildHandler::invite(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_GUILD_INVITE);
@@ -110,14 +110,14 @@ void GuildHandler::inviteResponse(const int guildId,
 {
     createOutPacket(CMSG_GUILD_INVITE_REPLY);
     outMsg.writeInt32(guildId, "guild id");
-    outMsg.writeInt8(response, "response");
+    outMsg.writeInt8(static_cast<int8_t>(response), "response");
     outMsg.writeInt8(0, "unused");
     outMsg.writeInt16(0, "unused");
 }
 
 void GuildHandler::leave(const int guildId) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     createOutPacket(CMSG_GUILD_LEAVE);
@@ -130,7 +130,7 @@ void GuildHandler::leave(const int guildId) const
 void GuildHandler::kick(const GuildMember *restrict const member,
                         const std::string &restrict reason) const
 {
-    if (!member || !member->getGuild())
+    if ((member == nullptr) || (member->getGuild() == nullptr))
         return;
 
     createOutPacket(CMSG_GUILD_EXPULSION);
@@ -142,7 +142,7 @@ void GuildHandler::kick(const GuildMember *restrict const member,
 
 void GuildHandler::chat(const std::string &text) const
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const std::string str = std::string(localPlayer->getName()).append(
@@ -189,7 +189,7 @@ void GuildHandler::info() const
 void GuildHandler::changeMemberPostion(const GuildMember *const member,
                                        const int level) const
 {
-    if (!member || !member->getGuild())
+    if ((member == nullptr) || (member->getGuild() == nullptr))
         return;
 
     createOutPacket(CMSG_GUILD_CHANGE_MEMBER_POS);
@@ -216,7 +216,7 @@ void GuildHandler::checkMaster() const
 
 void GuildHandler::requestAlliance(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_GUILD_ALLIANCE_REQUEST);
@@ -230,7 +230,7 @@ void GuildHandler::requestAllianceResponse(const int beingId,
 {
     createOutPacket(CMSG_GUILD_ALLIANCE_REPLY);
     outMsg.writeInt32(beingId, "account id");
-    outMsg.writeInt32(accept, "accept flag");
+    outMsg.writeInt32(static_cast<int32_t>(accept), "accept flag");
 }
 
 void GuildHandler::endAlliance(const int guildId,
@@ -258,7 +258,7 @@ void GuildHandler::changePostionInfo(const int posId,
 
 void GuildHandler::requestOpposition(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_GUILD_OPPOSITION);
diff --git a/src/net/eathena/guildrecv.cpp b/src/net/eathena/guildrecv.cpp
index 6d829299b..cb31788b6 100644
--- a/src/net/eathena/guildrecv.cpp
+++ b/src/net/eathena/guildrecv.cpp
@@ -109,7 +109,7 @@ void GuildRecv::processGuildBasicInfo(Net::MessageIn &msg)
     std::string castle = msg.readString(16, "castles");
     msg.readInt32("unused");
 
-    if (guildTab && showBasicInfo)
+    if ((guildTab != nullptr) && showBasicInfo)
     {
         showBasicInfo = false;
         // TRANSLATORS: guild info message
@@ -142,7 +142,7 @@ void GuildRecv::processGuildBasicInfo(Net::MessageIn &msg)
     }
 
     Guild *const g = Guild::getGuild(CAST_S16(guildId));
-    if (!g)
+    if (g == nullptr)
         return;
     g->setName(name);
     g->setEmblemId(emblem);
@@ -169,7 +169,7 @@ void GuildRecv::processGuildMemberList(Net::MessageIn &msg)
     if (length < 4)
         return;
     const int count = (length - 4) / 104;
-    if (!taGuild)
+    if (taGuild == nullptr)
     {
         logger->log1("!taGuild");
         return;
@@ -195,9 +195,9 @@ void GuildRecv::processGuildMemberList(Net::MessageIn &msg)
         std::string name = msg.readString(24, "name");
 
         GuildMember *const m = taGuild->addMember(id, charId, name);
-        if (m)
+        if (m != nullptr)
         {
-            m->setOnline(online);
+            m->setOnline(online != 0);
             m->setID(id);
             m->setCharId(charId);
             m->setGender(Being::intToGender(CAST_U8(gender)));
@@ -205,11 +205,11 @@ void GuildRecv::processGuildMemberList(Net::MessageIn &msg)
             m->setExp(exp);
             m->setPos(pos);
             m->setRace(race);
-            if (actorManager)
+            if (actorManager != nullptr)
             {
                 Being *const being = actorManager->findBeingByName(
                     name, ActorType::Player);
-                if (being)
+                if (being != nullptr)
                 {
                     being->setGuildName(taGuild->getName());
                     if (being->getLevel() != level)
@@ -219,24 +219,24 @@ void GuildRecv::processGuildMemberList(Net::MessageIn &msg)
                     }
                 }
             }
-            if (online)
+            if (online != 0)
                 onlineNum ++;
             totalNum ++;
         }
     }
     taGuild->sort();
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         actorManager->updatePlayerGuild();
         actorManager->updatePlayerColors();
     }
-    if (socialWindow)
+    if (socialWindow != nullptr)
         socialWindow->updateGuildCounter(onlineNum, totalNum);
 }
 
 void GuildRecv::processGuildPosNameList(Net::MessageIn &msg)
 {
-    if (!taGuild)
+    if (taGuild == nullptr)
     {
         logger->log1("!taGuild");
         return;
@@ -288,10 +288,10 @@ void GuildRecv::processGuildMemberPosChange(Net::MessageIn &msg)
     const BeingId accountId = msg.readBeingId("account id");
     const int charId = msg.readInt32("char id");
     const int pos = msg.readInt32("position");
-    if (taGuild)
+    if (taGuild != nullptr)
     {
         GuildMember *const m = taGuild->getMember(accountId, charId);
-        if (m)
+        if (m != nullptr)
             m->setPos(pos);
     }
 }
@@ -313,7 +313,7 @@ void GuildRecv::processGuildSkillInfo(Net::MessageIn &msg)
     const int count = (msg.readInt16("len") - 6) / 37;
     msg.readInt16("skill points");
 
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->hideSkills(SkillOwner::Guild);
     for (int i = 0; i < count; i++)
     {
@@ -326,7 +326,7 @@ void GuildRecv::processGuildSkillInfo(Net::MessageIn &msg)
         const std::string name = msg.readString(24, "skill name");
         const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
         PlayerInfo::setSkillLevel(skillId, level);
-        if (skillDialog)
+        if (skillDialog != nullptr)
         {
             if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
             {
@@ -335,7 +335,7 @@ void GuildRecv::processGuildSkillInfo(Net::MessageIn &msg)
             }
         }
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->updateModels();
 }
 
@@ -343,7 +343,7 @@ void GuildRecv::processGuildNotice(Net::MessageIn &msg)
 {
     const std::string msg1 = msg.readString(60, "msg1");
     const std::string msg2 = msg.readString(120, "msg2");
-    if (guildTab)
+    if (guildTab != nullptr)
     {
         guildTab->chatLog(msg1, ChatMsgType::BY_SERVER);
         guildTab->chatLog(msg2, ChatMsgType::BY_SERVER);
@@ -355,14 +355,14 @@ void GuildRecv::processGuildInvite(Net::MessageIn &msg)
     const int guildId = msg.readInt32("guild id");
     const std::string guildName = msg.readString(24, "guild name");
 
-    if (socialWindow)
+    if (socialWindow != nullptr)
         socialWindow->showGuildInvite(guildName, guildId, "");
 }
 
 void GuildRecv::processGuildInviteAck(Net::MessageIn &msg)
 {
     const uint8_t flag = msg.readUInt8("flag");
-    if (!guildTab)
+    if (guildTab == nullptr)
         return;
 
     switch (flag)
@@ -394,15 +394,15 @@ void GuildRecv::processGuildLeave(Net::MessageIn &msg)
     const std::string nick = msg.readString(24, "nick");
     msg.readString(40, "message");
 
-    if (taGuild)
+    if (taGuild != nullptr)
         taGuild->removeMember(nick);
 
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (nick == localPlayer->getName())
     {
-        if (taGuild)
+        if (taGuild != nullptr)
         {
             taGuild->removeFromMembers();
             taGuild->clearMembers();
@@ -411,22 +411,22 @@ void GuildRecv::processGuildLeave(Net::MessageIn &msg)
         NotifyManager::notify(NotifyTypes::GUILD_LEFT);
         delete2(guildTab)
 
-        if (socialWindow && taGuild)
+        if ((socialWindow != nullptr) && (taGuild != nullptr))
             socialWindow->removeTab(taGuild);
-        if (actorManager)
+        if (actorManager != nullptr)
             actorManager->updatePlayerColors();
     }
     else
     {
         NotifyManager::notify(NotifyTypes::GUILD_USER_LEFT, nick);
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             Being *const b = actorManager->findBeingByName(
                 nick, ActorType::Player);
 
-            if (b)
+            if (b != nullptr)
                 b->clearGuilds();
-            if (taGuild)
+            if (taGuild != nullptr)
                 taGuild->removeMember(nick);
         }
     }
@@ -438,7 +438,7 @@ void GuildRecv::processGuildMessage(Net::MessageIn &msg)
 
     if (msgLength <= 0)
         return;
-    if (guildTab)
+    if (guildTab != nullptr)
     {
         std::string chatMsg = msg.readString(msgLength, "message");
         const size_t pos = chatMsg.find(" : ", 0);
@@ -505,15 +505,15 @@ void GuildRecv::processGuildBroken(Net::MessageIn &msg)
 
 void GuildRecv::processGuildExpulsionContinue(const std::string &nick)
 {
-    if (taGuild)
+    if (taGuild != nullptr)
         taGuild->removeMember(nick);
 
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     if (nick == localPlayer->getName())
     {
-        if (taGuild)
+        if (taGuild != nullptr)
         {
             taGuild->removeFromMembers();
             taGuild->clearMembers();
@@ -521,22 +521,22 @@ void GuildRecv::processGuildExpulsionContinue(const std::string &nick)
         NotifyManager::notify(NotifyTypes::GUILD_KICKED);
         delete2(guildTab)
 
-        if (socialWindow && taGuild)
+        if ((socialWindow != nullptr) && (taGuild != nullptr))
             socialWindow->removeTab(taGuild);
-        if (actorManager)
+        if (actorManager != nullptr)
             actorManager->updatePlayerColors();
     }
     else
     {
         NotifyManager::notify(NotifyTypes::GUILD_USER_KICKED, nick);
-        if (actorManager)
+        if (actorManager != nullptr)
         {
             Being *const b = actorManager->findBeingByName(
                 nick, ActorType::Player);
 
-            if (b)
+            if (b != nullptr)
                 b->clearGuilds();
-            if (taGuild)
+            if (taGuild != nullptr)
                 taGuild->removeMember(nick);
         }
     }
@@ -547,10 +547,10 @@ void GuildRecv::processGuildUpdateCoords(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("account id");
     const int x = msg.readInt16("x");
     const int y = msg.readInt16("y");
-    if (taGuild)
+    if (taGuild != nullptr)
     {
         GuildMember *const m = taGuild->getMember(id);
-        if (m)
+        if (m != nullptr)
         {
             m->setX(x);
             m->setY(y);
@@ -569,24 +569,24 @@ void GuildRecv::processGuildPositionInfo(Net::MessageIn &msg)
     std::string guildName = msg.readString(24, "guild name");
 
     Guild *const g = Guild::getGuild(CAST_S16(guildId));
-    if (!g)
+    if (g == nullptr)
         return;
 
     g->setName(guildName);
     g->setEmblemId(emblem);
-    if (!taGuild)
+    if (taGuild == nullptr)
         taGuild = g;
-    if (!guildTab && chatWindow)
+    if ((guildTab == nullptr) && (chatWindow != nullptr))
     {
         guildTab = new GuildTab(chatWindow);
         if (config.getBoolValue("showChatHistory"))
             guildTab->loadFromLogFile("#Guild");
-        if (localPlayer)
+        if (localPlayer != nullptr)
             localPlayer->addGuild(taGuild);
         guildHandler->memberList();
     }
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         localPlayer->setGuild(g);
         localPlayer->setGuildName(g->getName());
@@ -602,17 +602,17 @@ void GuildRecv::processGuildMemberLogin(Net::MessageIn &msg)
         msg.readInt16("sex")));
     msg.readInt16("hair");
     msg.readInt16("hair color");
-    if (taGuild)
+    if (taGuild != nullptr)
     {
         GuildMember *const m = taGuild->getMember(accountId, charId);
-        if (m)
+        if (m != nullptr)
         {
-            m->setOnline(online);
-            if (online)
+            m->setOnline(online != 0);
+            if (online != 0)
                 m->setGender(gender);
-            if (guildTab)
+            if (guildTab != nullptr)
                 guildTab->showOnline(m->getName(), fromBool(online, Online));
-            if (socialWindow)
+            if (socialWindow != nullptr)
                 socialWindow->updateGuildCounter();
         }
     }
diff --git a/src/net/eathena/homunculusrecv.cpp b/src/net/eathena/homunculusrecv.cpp
index a30e81662..204b618a7 100644
--- a/src/net/eathena/homunculusrecv.cpp
+++ b/src/net/eathena/homunculusrecv.cpp
@@ -46,7 +46,7 @@ namespace EAthena
 
 void HomunculusRecv::processHomunculusSkills(Net::MessageIn &msg)
 {
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->hideSkills(SkillOwner::Homunculus);
 
     const int count = (msg.readInt16("len") - 4) / 37;
@@ -62,7 +62,7 @@ void HomunculusRecv::processHomunculusSkills(Net::MessageIn &msg)
         const std::string name = msg.readString(24, "skill name");
         const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
         PlayerInfo::setSkillLevel(skillId, level);
-        if (skillDialog)
+        if (skillDialog != nullptr)
         {
             if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
             {
@@ -71,7 +71,7 @@ void HomunculusRecv::processHomunculusSkills(Net::MessageIn &msg)
             }
         }
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->updateModels();
 }
 
@@ -82,7 +82,7 @@ void HomunculusRecv::processHomunculusData(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("homunculus id");
     Being *const dstBeing = actorManager->findBeing(id);
     const int data = msg.readInt32("data");
-    if (!cmd)  // pre init
+    if (cmd == 0)  // pre init
     {
         HomunculusInfo *const info = new HomunculusInfo;
         info->id = id;
@@ -91,7 +91,7 @@ void HomunculusRecv::processHomunculusData(Net::MessageIn &msg)
         return;
     }
     HomunculusInfo *const info = PlayerInfo::getHomunculus();
-    if (!info)
+    if (info == nullptr)
         return;
     switch (cmd)
     {
@@ -164,7 +164,7 @@ void HomunculusRecv::processHomunculusInfo(Net::MessageIn &msg)
 
     PlayerInfo::updateAttrs();
     HomunculusInfo *const info = PlayerInfo::getHomunculus();
-    if (!info)  // we can't find homunculus being because id is missing
+    if (info == nullptr)
         return;
     Being *const dstBeing = actorManager->findBeing(info->id);
 
@@ -185,10 +185,10 @@ void HomunculusRecv::processHomunculusSkillUp(Net::MessageIn &msg)
     const int range = msg.readInt16("range");
     const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
 
-    if (skillDialog && PlayerInfo::getSkillLevel(skillId) != level)
+    if (skillDialog != nullptr && PlayerInfo::getSkillLevel(skillId) != level)
         skillDialog->playUpdateEffect(skillId);
     PlayerInfo::setSkillLevel(skillId, level);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         if (!skillDialog->updateSkill(skillId, range,
             up, SkillType::Unknown, sp))
@@ -204,7 +204,7 @@ void HomunculusRecv::processHomunculusFood(Net::MessageIn &msg)
 {
     const int flag = msg.readUInt8("fail");
     const int itemId = msg.readInt16("food id");
-    if (flag)
+    if (flag != 0)
     {
         NotifyManager::notify(NotifyTypes::HOMUNCULUS_FEED_OK);
     }
@@ -220,7 +220,7 @@ void HomunculusRecv::processHomunculusExp(Net::MessageIn &msg)
 {
     const int exp = msg.readInt32("exp");
     msg.readInt32("unused");
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->addHomunXpMessage(exp);
 }
 
diff --git a/src/net/eathena/inventoryhandler.cpp b/src/net/eathena/inventoryhandler.cpp
index a7fde5a05..6a5152fad 100644
--- a/src/net/eathena/inventoryhandler.cpp
+++ b/src/net/eathena/inventoryhandler.cpp
@@ -80,7 +80,7 @@ InventoryHandler::~InventoryHandler()
 
 void InventoryHandler::equipItem(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     createOutPacket(CMSG_PLAYER_EQUIP);
@@ -96,7 +96,7 @@ void InventoryHandler::equipItem(const Item *const item) const
 
 void InventoryHandler::unequipItem(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     createOutPacket(CMSG_PLAYER_UNEQUIP);
@@ -106,7 +106,7 @@ void InventoryHandler::unequipItem(const Item *const item) const
 
 void InventoryHandler::useItem(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     createOutPacket(CMSG_PLAYER_INVENTORY_USE);
@@ -117,7 +117,7 @@ void InventoryHandler::useItem(const Item *const item) const
 
 void InventoryHandler::dropItem(const Item *const item, const int amount) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     createOutPacket(CMSG_PLAYER_INVENTORY_DROP);
@@ -477,7 +477,7 @@ void InventoryHandler::moveItem2(const InventoryTypeT source,
     }
 
     // for packetVersion < 20101124 need use other packet offset
-    if (packet)
+    if (packet != 0)
     {
         createOutPacket(packet);
         outMsg.writeInt16(CAST_S16(slot + offset), "index");
@@ -487,7 +487,7 @@ void InventoryHandler::moveItem2(const InventoryTypeT source,
 
 void InventoryHandler::useCard(const Item *const item)
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     mItemIndex = item->getInvIndex();
@@ -509,7 +509,7 @@ void InventoryHandler::insertCard(const int cardIndex,
 void InventoryHandler::favoriteItem(const Item *const item,
                                     const bool favorite) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
     if (packetVersion < 20120410)
         return;
@@ -517,12 +517,12 @@ void InventoryHandler::favoriteItem(const Item *const item,
     outMsg.writeInt16(CAST_S16(item->getInvIndex()
         + INVENTORY_OFFSET),
         "item index");
-    outMsg.writeInt8(favorite, "favorite flag");
+    outMsg.writeInt8(static_cast<int8_t>(favorite), "favorite flag");
 }
 
 void InventoryHandler::selectEgg(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
     createOutPacket(CMSG_PET_SELECT_EGG);
     outMsg.writeInt16(CAST_S16(
diff --git a/src/net/eathena/inventoryrecv.cpp b/src/net/eathena/inventoryrecv.cpp
index 5403e773b..08cd1975e 100644
--- a/src/net/eathena/inventoryrecv.cpp
+++ b/src/net/eathena/inventoryrecv.cpp
@@ -100,12 +100,12 @@ namespace InventoryRecv
 void InventoryRecv::processPlayerEquipment(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerEquipment")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
     msg.readInt16("len");
     Equipment *const equipment = PlayerInfo::getEquipment();
-    if (equipment && !equipment->getBackend())
+    if ((equipment != nullptr) && (equipment->getBackend() == nullptr))
     {   // look like SMSG_PLAYER_INVENTORY was not received
         Ea::InventoryRecv::mEquips.clear();
         equipment->setBackend(&Ea::InventoryRecv::mEquips);
@@ -173,7 +173,7 @@ void InventoryRecv::processPlayerEquipment(Net::MessageIn &msg)
             flags.byte = msg.readUInt8("flags");
         else
             flags.byte = 0;
-        if (inventory)
+        if (inventory != nullptr)
         {
             inventory->setItem(index,
                 itemId,
@@ -191,7 +191,7 @@ void InventoryRecv::processPlayerEquipment(Net::MessageIn &msg)
         }
         delete options;
 
-        if (equipType)
+        if (equipType != 0)
         {
             Ea::InventoryRecv::mEquips.setEquipment(
                 InventoryRecv::getSlot(equipType),
@@ -204,11 +204,11 @@ void InventoryRecv::processPlayerEquipment(Net::MessageIn &msg)
 void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerInventoryAdd")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
-    if (PlayerInfo::getEquipment()
-        && !PlayerInfo::getEquipment()->getBackend())
+    if ((PlayerInfo::getEquipment() != nullptr)
+        && (PlayerInfo::getEquipment()->getBackend() == nullptr))
     {   // look like SMSG_PLAYER_INVENTORY was not received
         Ea::InventoryRecv::mEquips.clear();
         PlayerInfo::getEquipment()->setBackend(&Ea::InventoryRecv::mEquips);
@@ -259,7 +259,7 @@ void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
         Ea::InventoryRecv::mSentPickups.pop();
     }
 
-    if (err)
+    if (err != 0u)
     {
         PickupT pickup;
         switch (err)
@@ -287,7 +287,7 @@ void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
                 UNIMPLEMENTEDPACKETFIELD(err);
                 break;
         }
-        if (localPlayer)
+        if (localPlayer != nullptr)
         {
             if (itemId == 0)
             {
@@ -309,7 +309,7 @@ void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
     }
     else
     {
-        if (localPlayer)
+        if (localPlayer != nullptr)
         {
             if (itemId == 0)
             {
@@ -329,11 +329,11 @@ void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
             }
         }
 
-        if (inventory)
+        if (inventory != nullptr)
         {
             const Item *const item = inventory->getItem(index);
 
-            if (item && item->getId() == itemId)
+            if ((item != nullptr) && item->getId() == itemId)
                 amount += item->getQuantity();
 
             inventory->setItem(index,
@@ -359,16 +359,16 @@ void InventoryRecv::processPlayerInventoryAdd(Net::MessageIn &msg)
 void InventoryRecv::processPlayerInventory(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerInventory")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
-    if (PlayerInfo::getEquipment())
+    if (PlayerInfo::getEquipment() != nullptr)
     {
         // Clear inventory - this will be a complete refresh
         Ea::InventoryRecv::mEquips.clear();
         PlayerInfo::getEquipment()->setBackend(&Ea::InventoryRecv::mEquips);
     }
 
-    if (inventory)
+    if (inventory != nullptr)
         inventory->clear();
 
     msg.readInt16("len");
@@ -417,7 +417,7 @@ void InventoryRecv::processPlayerInventory(Net::MessageIn &msg)
         else
             flags.byte = 0;
 
-        if (inventory)
+        if (inventory != nullptr)
         {
             inventory->setItem(index,
                 itemId,
@@ -556,7 +556,7 @@ void InventoryRecv::processPlayerUnEquip(Net::MessageIn &msg)
         equipType = msg.readInt16("wear location");
     const uint8_t flag = msg.readUInt8("result");
 
-    if (flag)
+    if (flag != 0u)
     {
         NotifyManager::notify(NotifyTypes::UNEQUIP_FAILED);
     }
@@ -566,7 +566,7 @@ void InventoryRecv::processPlayerUnEquip(Net::MessageIn &msg)
             InventoryRecv::getSlot(equipType),
             -1);
     }
-    if (equipType & 0x8000)
+    if ((equipType & 0x8000) != 0)
         ArrowsListener::distributeEvent();
     BLOCK_END("InventoryRecv::processPlayerUnEquip")
 }
@@ -574,7 +574,7 @@ void InventoryRecv::processPlayerUnEquip(Net::MessageIn &msg)
 void InventoryRecv::processPlayerInventoryRemove2(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerInventoryRemove2")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
     const DeleteItemReasonT reason = static_cast<DeleteItemReasonT>(
@@ -582,7 +582,7 @@ void InventoryRecv::processPlayerInventoryRemove2(Net::MessageIn &msg)
     const int index = msg.readInt16("index") - INVENTORY_OFFSET;
     const int amount = msg.readInt16("amount");
 
-    if (inventory)
+    if (inventory != nullptr)
     {
         if (Item *const item = inventory->getItem(index))
         {
@@ -771,7 +771,7 @@ void InventoryRecv::processPlayerStorageAdd(Net::MessageIn &msg)
     }
     else
     {
-        if (Ea::InventoryRecv::mStorage)
+        if (Ea::InventoryRecv::mStorage != nullptr)
         {
             Ea::InventoryRecv::mStorage->setItem(index,
                 itemId,
@@ -797,7 +797,7 @@ void InventoryRecv::processPlayerUseCard(Net::MessageIn &msg)
     const Inventory *const inv = PlayerInfo::getInventory();
     const int index = inventoryHandler->getItemIndex();
     const Item *item1 = nullptr;
-    if (inv)
+    if (inv != nullptr)
         item1 = inv->getItem(index);
     SellDialog *const dialog = CREATEWIDGETR(InsertCardDialog,
         index, item1);
@@ -806,10 +806,10 @@ void InventoryRecv::processPlayerUseCard(Net::MessageIn &msg)
     for (int f = 0; f < count; f ++)
     {
         const int itemIndex = msg.readInt16("item index") - INVENTORY_OFFSET;
-        if (!inv)
+        if (inv == nullptr)
             continue;
         const Item *const item = inv->getItem(itemIndex);
-        if (!item)
+        if (item == nullptr)
             continue;
         dialog->addItem(item, 0);
     }
@@ -819,7 +819,7 @@ void InventoryRecv::processPlayerInsertCard(Net::MessageIn &msg)
 {
     const int itemIndex = msg.readInt16("item index") - INVENTORY_OFFSET;
     const int cardIndex = msg.readInt16("card index") - INVENTORY_OFFSET;
-    if (msg.readUInt8("flag"))
+    if (msg.readUInt8("flag") != 0u)
     {
         NotifyManager::notify(NotifyTypes::CARD_INSERT_FAILED);
     }
@@ -827,11 +827,11 @@ void InventoryRecv::processPlayerInsertCard(Net::MessageIn &msg)
     {
         NotifyManager::notify(NotifyTypes::CARD_INSERT_SUCCESS);
         Inventory *const inv = PlayerInfo::getInventory();
-        if (!inv)
+        if (inv == nullptr)
             return;
         Item *const card = inv->getItem(cardIndex);
         int cardId = 0;
-        if (card)
+        if (card != nullptr)
         {
             cardId = card->getId();
             card->increaseQuantity(-1);
@@ -839,7 +839,7 @@ void InventoryRecv::processPlayerInsertCard(Net::MessageIn &msg)
                 inv->removeItemAt(cardIndex);
         }
         Item *const item = inv->getItem(itemIndex);
-        if (item)
+        if (item != nullptr)
         {
             item->addCard(cardId);
             item->updateColor();
@@ -862,7 +862,7 @@ void InventoryRecv::processPlayerItemRentalTime(Net::MessageIn &msg)
 
 void InventoryRecv::processPlayerItemRentalExpired(Net::MessageIn &msg)
 {
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
     const int index = msg.readInt16("index") - INVENTORY_OFFSET;
@@ -871,7 +871,7 @@ void InventoryRecv::processPlayerItemRentalExpired(Net::MessageIn &msg)
 
     NotifyManager::notify(NotifyTypes::RENTAL_TIME_EXPIRED,
         info.getName());
-    if (inventory)
+    if (inventory != nullptr)
     {
         if (Item *const item = inventory->getItem(index))
         {
@@ -888,7 +888,7 @@ void InventoryRecv::processPlayerStorageRemove(Net::MessageIn &msg)
     // Move an item out of storage
     const int index = msg.readInt16("index") - STORAGE_OFFSET;
     const int amount = msg.readInt32("amount");
-    if (Ea::InventoryRecv::mStorage)
+    if (Ea::InventoryRecv::mStorage != nullptr)
     {
         if (Item *const item = Ea::InventoryRecv::mStorage->getItem(index))
         {
@@ -912,7 +912,7 @@ void InventoryRecv::processCartInfo(Net::MessageIn &msg)
         return;
 
     Inventory *const inv = PlayerInfo::getCartInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     inv->resize(size);
@@ -943,7 +943,7 @@ void InventoryRecv::processCartRemove(Net::MessageIn &msg)
 void InventoryRecv::processPlayerCartAdd(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerCartAdd")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getCartInventory() : nullptr;
 
     const int index = msg.readInt16("index") - INVENTORY_OFFSET;
@@ -975,11 +975,11 @@ void InventoryRecv::processPlayerCartAdd(Net::MessageIn &msg)
     }
 
     // check what cart was created, if not add delayed items
-    if (inventory && inventory->getSize() > 0)
+    if ((inventory != nullptr) && inventory->getSize() > 0)
     {
         const Item *const item = inventory->getItem(index);
 
-        if (item && item->getId() == itemId)
+        if ((item != nullptr) && item->getId() == itemId)
             amount += item->getQuantity();
 
         inventory->setItem(index,
@@ -1170,7 +1170,7 @@ void InventoryRecv::processPlayerCartRemove(Net::MessageIn &msg)
     const int amount = msg.readInt32("amount");
 
     Inventory *const inv = PlayerInfo::getCartInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
 
     if (Item *const item = inv->getItem(index))
@@ -1209,9 +1209,9 @@ void InventoryRecv::processPlayerRefine(Net::MessageIn &msg)
     const Item *item = nullptr;
     int notifyType;
     std::string itemName;
-    if (inv)
+    if (inv != nullptr)
         item = inv->getItem(index);
-    if (item)
+    if (item != nullptr)
     {
         itemName = item->getName();
     }
@@ -1340,11 +1340,11 @@ void InventoryRecv::processBindItem(Net::MessageIn &msg)
 {
     const int index = msg.readInt16("item index") - INVENTORY_OFFSET;
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (inv)
+    if (inv != nullptr)
     {
         std::string itemName;
         const Item *const item = inv->getItem(index);
-        if (item)
+        if (item != nullptr)
         {
             itemName = item->getName();
         }
@@ -1360,16 +1360,16 @@ void InventoryRecv::processBindItem(Net::MessageIn &msg)
 void InventoryRecv::processPlayerInventoryRemove(Net::MessageIn &msg)
 {
     BLOCK_START("InventoryRecv::processPlayerInventoryRemove")
-    Inventory *const inventory = localPlayer
+    Inventory *const inventory = localPlayer != nullptr
         ? PlayerInfo::getInventory() : nullptr;
 
     const int index = msg.readInt16("index") - INVENTORY_OFFSET;
     const int amount = msg.readInt16("amount");
-    if (inventory)
+    if (inventory != nullptr)
     {
         if (Item *const item = inventory->getItem(index))
         {
-            if (amount)
+            if (amount != 0)
             {
                 NotifyManager::notify(NotifyTypes::DELETE_ITEM_DROPPED,
                     item->getName());
@@ -1398,12 +1398,12 @@ int InventoryRecv::getSlot(const int eAthenaSlot)
     if (eAthenaSlot == 0)
         return EquipSlot::VECTOREND;
 
-    if (eAthenaSlot & 0x8000)
+    if ((eAthenaSlot & 0x8000) != 0)
         return inventoryHandler->getProjectileSlot();
 
     unsigned int mask = 1;
     int position = 0;
-    while (!(eAthenaSlot & mask))
+    while ((eAthenaSlot & mask) == 0u)
     {
         mask <<= 1;
         position++;
diff --git a/src/net/eathena/itemrecv.cpp b/src/net/eathena/itemrecv.cpp
index 062063a55..f0a6bd585 100644
--- a/src/net/eathena/itemrecv.cpp
+++ b/src/net/eathena/itemrecv.cpp
@@ -50,7 +50,7 @@ void ItemRecv::processItemDropped(Net::MessageIn &msg)
     const int subY = CAST_S32(msg.readInt8("suby"));
     const int amount = msg.readInt16("count");
 
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         actorManager->createItem(id,
             itemId,
@@ -84,7 +84,7 @@ void ItemRecv::processItemDropped2(Net::MessageIn &msg)
     const int subX = CAST_S32(msg.readInt8("subx"));
     const int subY = CAST_S32(msg.readInt8("suby"));
 
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         actorManager->createItem(id,
             itemId,
@@ -124,7 +124,7 @@ void ItemRecv::processItemVisible(Net::MessageIn &msg)
     const int subX = CAST_S32(msg.readInt8("sub x"));
     const int subY = CAST_S32(msg.readInt8("sub y"));
 
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         actorManager->createItem(id,
             itemId,
@@ -159,7 +159,7 @@ void ItemRecv::processItemVisible2(Net::MessageIn &msg)
     const int subX = CAST_S32(msg.readInt8("sub x"));
     const int subY = CAST_S32(msg.readInt8("sub y"));
 
-    if (actorManager)
+    if (actorManager != nullptr)
     {
         actorManager->createItem(id,
             itemId,
diff --git a/src/net/eathena/loginhandler.cpp b/src/net/eathena/loginhandler.cpp
index 08c601434..f6ebe8e45 100644
--- a/src/net/eathena/loginhandler.cpp
+++ b/src/net/eathena/loginhandler.cpp
@@ -54,7 +54,7 @@ LoginHandler::~LoginHandler()
 
 void LoginHandler::connect() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return;
 
     Network::mInstance->connect(mServer);
@@ -71,7 +71,7 @@ void LoginHandler::connect() const
 
 bool LoginHandler::isConnected() const
 {
-    if (!Network::mInstance)
+    if (Network::mInstance == nullptr)
         return false;
 
     return Network::mInstance->isConnected();
@@ -79,8 +79,11 @@ bool LoginHandler::isConnected() const
 
 void LoginHandler::disconnect() const
 {
-    if (Network::mInstance && Network::mInstance->getServer() == mServer)
+    if (Network::mInstance != nullptr &&
+        Network::mInstance->getServer() == mServer)
+    {
         Network::mInstance->disconnect();
+    }
 }
 
 void LoginHandler::changePassword(const std::string &restrict oldPassword,
diff --git a/src/net/eathena/mailrecv.cpp b/src/net/eathena/mailrecv.cpp
index 38366d986..c098b6857 100644
--- a/src/net/eathena/mailrecv.cpp
+++ b/src/net/eathena/mailrecv.cpp
@@ -45,7 +45,7 @@ void MailRecv::processMailOpen(Net::MessageIn &msg)
     switch (flag)
     {
         case 0:  // open window
-            if (mailWindow)
+            if (mailWindow != nullptr)
             {
                 if (!mailWindow->isWindowVisible())
                     mailWindow->setVisible(Visible_true);
@@ -54,7 +54,7 @@ void MailRecv::processMailOpen(Net::MessageIn &msg)
             break;
 
         case 1:  // close window
-            if (mailWindow)
+            if (mailWindow != nullptr)
             {
                 if (mailWindow->isWindowVisible())
                     mailWindow->setVisible(Visible_false);
@@ -79,7 +79,7 @@ void MailRecv::processMailList(Net::MessageIn &msg)
         MailMessage *const mail = new MailMessage;
         mail->id = msg.readInt32("message id");
         mail->title = msg.readString(40, "title");
-        mail->unread = msg.readUInt8("unread flag") ? true : false;
+        mail->unread = msg.readUInt8("unread flag") != 0u ? true : false;
         mail->sender = msg.readString(24, "sender name");
         mail->time = msg.readInt32("time stamp");
         mail->strTime = timeToStr(mail->time);
@@ -99,7 +99,7 @@ void MailRecv::processReadMail(Net::MessageIn &msg)
     mail->itemAmount = msg.readInt32("item amount");
     mail->itemId = msg.readInt16("item id");
     mail->itemType = msg.readInt16("item type");
-    mail->itemIdentify = msg.readUInt8("identify");
+    mail->itemIdentify = (msg.readUInt8("identify") != 0u);
     mail->itemAttribute = msg.readUInt8("attribute");
     mail->itemRefine = msg.readUInt8("refine");
     for (int f = 0; f < maxCards; f ++)
@@ -166,9 +166,9 @@ void MailRecv::processSetAttachmentAck(Net::MessageIn &msg)
 {
     const int index = msg.readInt16("index");
     const int flag = msg.readUInt8("flag");
-    if (flag)
+    if (flag != 0)
     {
-        if (index)
+        if (index != 0)
             NotifyManager::notify(NotifyTypes::MAIL_ATTACH_ITEM_ERROR);
         else
             NotifyManager::notify(NotifyTypes::MAIL_ATTACH_MONEY_ERROR);
@@ -179,7 +179,7 @@ void MailRecv::processDeleteAck(Net::MessageIn &msg)
 {
     const int mail = msg.readInt32("message id");
     const int flag = msg.readInt16("fail flag");
-    if (flag)
+    if (flag != 0)
     {
         NotifyManager::notify(NotifyTypes::MAIL_DELETE_ERROR);
     }
@@ -194,7 +194,7 @@ void MailRecv::processMailReturn(Net::MessageIn &msg)
 {
     const int mail = msg.readInt32("message id");
     const int flag = msg.readInt16("fail flag");
-    if (flag)
+    if (flag != 0)
     {
         NotifyManager::notify(NotifyTypes::MAIL_RETURN_ERROR);
     }
diff --git a/src/net/eathena/markethandler.cpp b/src/net/eathena/markethandler.cpp
index ba3304aa5..a75aec961 100644
--- a/src/net/eathena/markethandler.cpp
+++ b/src/net/eathena/markethandler.cpp
@@ -86,7 +86,7 @@ void MarketHandler::buyItems(const std::vector<ShopItem*> &items) const
         const ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
         const ItemTypeT type = item->getType();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         if (type == ItemType::Weapon ||
             type == ItemType::Armor ||
@@ -110,7 +110,7 @@ void MarketHandler::buyItems(const std::vector<ShopItem*> &items) const
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         item->increaseQuantity(usedQuantity);
         item->increaseUsedQuantity(-usedQuantity);
diff --git a/src/net/eathena/marketrecv.cpp b/src/net/eathena/marketrecv.cpp
index cfe7aa4c8..8563c67ca 100644
--- a/src/net/eathena/marketrecv.cpp
+++ b/src/net/eathena/marketrecv.cpp
@@ -61,7 +61,7 @@ void MarketRecv::processMarketOpen(Net::MessageIn &msg)
     if (npcId != BeingTypeId_zero)
     {
         const BeingInfo *const info = NPCDB::get(npcId);
-        if (info)
+        if (info != nullptr)
             currency = info->getCurrency();
         else
             currency = DEFAULT_CURRENCY;
@@ -99,7 +99,7 @@ void MarketRecv::processMarketBuyAck(Net::MessageIn &msg)
         msg.readInt16("amount");
         msg.readInt32("price");
     }
-    if (res)
+    if (res != 0)
         NotifyManager::notify(NotifyTypes::BUY_DONE);
     else
         NotifyManager::notify(NotifyTypes::BUY_FAILED);
diff --git a/src/net/eathena/mercenaryrecv.cpp b/src/net/eathena/mercenaryrecv.cpp
index 042c87451..594c96b6a 100644
--- a/src/net/eathena/mercenaryrecv.cpp
+++ b/src/net/eathena/mercenaryrecv.cpp
@@ -120,7 +120,7 @@ void MercenaryRecv::processMercenaryInfo(Net::MessageIn &msg)
         range);
     PlayerInfo::updateAttrs();
 
-    if (dstBeing && localPlayer)
+    if ((dstBeing != nullptr) && (localPlayer != nullptr))
     {
         MercenaryInfo *const mercenary = new MercenaryInfo;
         mercenary->id = dstBeing->getId();
@@ -134,7 +134,7 @@ void MercenaryRecv::processMercenaryInfo(Net::MessageIn &msg)
 
 void MercenaryRecv::processMercenarySkills(Net::MessageIn &msg)
 {
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->hideSkills(SkillOwner::Mercenary);
     const int count = (msg.readInt16("len") - 4) / 37;
     for (int f = 0; f < count; f ++)
@@ -148,7 +148,7 @@ void MercenaryRecv::processMercenarySkills(Net::MessageIn &msg)
         const std::string name = msg.readString(24, "skill name");
         const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
         PlayerInfo::setSkillLevel(skillId, level);
-        if (skillDialog)
+        if (skillDialog != nullptr)
         {
             if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
             {
@@ -157,14 +157,14 @@ void MercenaryRecv::processMercenarySkills(Net::MessageIn &msg)
             }
         }
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->updateModels();
 }
 
 void MercenaryRecv::handleMercenaryMessage(const int cmd)
 {
     PlayerInfo::setMercenary(nullptr);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->hideSkills(SkillOwner::Mercenary);
         skillDialog->updateModels();
diff --git a/src/net/eathena/network.cpp b/src/net/eathena/network.cpp
index 8ea30fe50..8b3504e4e 100644
--- a/src/net/eathena/network.cpp
+++ b/src/net/eathena/network.cpp
@@ -207,7 +207,7 @@ void Network::dispatchMessages()
         if (msgId < messagesSize)
         {
             const PacketFuncPtr func = mPackets[msgId].func;
-            if (func)
+            if (func != nullptr)
                 func(msg);
             else
                 logger->log("Unhandled packet: %u 0x%x", msgId, msgId);
diff --git a/src/net/eathena/npchandler.cpp b/src/net/eathena/npchandler.cpp
index 5f2da7255..85349ce9d 100644
--- a/src/net/eathena/npchandler.cpp
+++ b/src/net/eathena/npchandler.cpp
@@ -57,7 +57,7 @@ NpcHandler::NpcHandler() :
 
 void NpcHandler::talk(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
     createOutPacket(CMSG_NPC_TALK);
     outMsg.writeBeingId(being->getId(), "npc id");
@@ -80,7 +80,7 @@ void NpcHandler::closeDialog(const BeingId npcId)
     if (it != NpcDialog::mNpcDialogs.end())
     {
         NpcDialog *const dialog = (*it).second;
-        if (dialog)
+        if (dialog != nullptr)
             dialog->close();
         if (dialog == Ea::NpcRecv::mDialog)
             Ea::NpcRecv::mDialog = nullptr;
@@ -125,7 +125,7 @@ void NpcHandler::stringInput(const BeingId npcId,
 
 void NpcHandler::buy(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
     createOutPacket(CMSG_NPC_BUY_SELL_REQUEST);
     outMsg.writeBeingId(being->getId(), "npc id");
@@ -169,7 +169,7 @@ void NpcHandler::buyItems(std::vector<ShopItem*> &items) const
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
         const ItemTypeT type = item->getType();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         if (type == ItemType::Weapon ||
             type == ItemType::Armor ||
@@ -193,7 +193,7 @@ void NpcHandler::buyItems(std::vector<ShopItem*> &items) const
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         item->increaseUsedQuantity(-usedQuantity);
         item->update();
@@ -237,7 +237,7 @@ void NpcHandler::sellItems(std::vector<ShopItem*> &items) const
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         cnt ++;
     }
@@ -248,7 +248,7 @@ void NpcHandler::sellItems(std::vector<ShopItem*> &items) const
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         item->increaseUsedQuantity(-usedQuantity);
         item->update();
@@ -339,7 +339,7 @@ BeingId NpcHandler::getNpc(Net::MessageIn &msg,
         {
             CREATEWIDGETV(Ea::NpcRecv::mDialog, NpcDialog, npcId);
             Ea::NpcRecv::mDialog->saveCamera();
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 localPlayer->stopWalking(false);
             NpcDialog::mNpcDialogs[npcId] = Ea::NpcRecv::mDialog;
         }
@@ -347,10 +347,10 @@ BeingId NpcHandler::getNpc(Net::MessageIn &msg,
     else
     {
         NpcDialog *const dialog = diag->second;
-        if (Ea::NpcRecv::mDialog && Ea::NpcRecv::mDialog != dialog)
+        if (Ea::NpcRecv::mDialog != nullptr && Ea::NpcRecv::mDialog != dialog)
             Ea::NpcRecv::mDialog->restoreCamera();
         Ea::NpcRecv::mDialog = dialog;
-        if (Ea::NpcRecv::mDialog)
+        if (Ea::NpcRecv::mDialog != nullptr)
             Ea::NpcRecv::mDialog->saveCamera();
     }
     return npcId;
diff --git a/src/net/eathena/npcrecv.cpp b/src/net/eathena/npcrecv.cpp
index c23d9d11b..875718768 100644
--- a/src/net/eathena/npcrecv.cpp
+++ b/src/net/eathena/npcrecv.cpp
@@ -47,7 +47,7 @@ void NpcRecv::processNpcCutin(Net::MessageIn &msg)
     Ea::NpcRecv::mRequestLang = false;
     const std::string image = msg.readString(64, "image name");
     const CutInT cutin = static_cast<CutInT>(msg.readUInt8("type"));
-    if (cutInWindow)
+    if (cutInWindow != nullptr)
         cutInWindow->show(image, cutin);
 }
 
@@ -91,7 +91,7 @@ void NpcRecv::processArea(Net::MessageIn &msg)
     Being *const dstBeing = actorManager->findBeing(
         msg.readBeingId("npc id"));
     const int area = msg.readInt32("area size");
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setAreaSize(area);
 }
 
@@ -113,7 +113,7 @@ void NpcRecv::processNpcSkin(Net::MessageIn &msg)
     const int len = msg.readInt16("len");
     npcHandler->getNpc(msg, NpcAction::Other);
     const std::string skin = msg.readString(len - 8, "skin");
-    if (Ea::NpcRecv::mDialog)
+    if (Ea::NpcRecv::mDialog != nullptr)
         Ea::NpcRecv::mDialog->setSkin(skin);
 }
 
diff --git a/src/net/eathena/partyhandler.cpp b/src/net/eathena/partyhandler.cpp
index 590f85ec8..dd0309f0d 100644
--- a/src/net/eathena/partyhandler.cpp
+++ b/src/net/eathena/partyhandler.cpp
@@ -61,11 +61,11 @@ void PartyHandler::create(const std::string &name) const
 
 void PartyHandler::invite(const std::string &name) const
 {
-    if (!actorManager)
+    if (actorManager == nullptr)
         return;
     const Being *const being = actorManager->findBeingByName(
         name, ActorType::Player);
-    if (being)
+    if (being != nullptr)
     {
         createOutPacket(CMSG_PARTY_INVITE);
         outMsg.writeBeingId(being->getId(), "account id");
@@ -82,7 +82,7 @@ void PartyHandler::invite(const std::string &name) const
 void PartyHandler::inviteResponse(const int partyId,
                                   const bool accept) const
 {
-    if (localPlayer)
+    if (localPlayer != nullptr)
     {
         createOutPacket(CMSG_PARTY_INVITED2);
         outMsg.writeInt32(partyId, "party id");
@@ -97,7 +97,7 @@ void PartyHandler::leave() const
 
 void PartyHandler::kick(const Being *const being) const
 {
-    if (being)
+    if (being != nullptr)
     {
         createOutPacket(CMSG_PARTY_KICK);
         outMsg.writeBeingId(being->getId(), "account id");
@@ -107,11 +107,11 @@ void PartyHandler::kick(const Being *const being) const
 
 void PartyHandler::kick(const std::string &name) const
 {
-    if (!Ea::taParty)
+    if (Ea::taParty == nullptr)
         return;
 
     const PartyMember *const m = Ea::taParty->getMember(name);
-    if (!m)
+    if (m == nullptr)
     {
         NotifyManager::notify(NotifyTypes::PARTY_USER_NOT_IN_PARTY, name);
         return;
@@ -183,7 +183,7 @@ void PartyHandler::changeLeader(const std::string &name) const
 {
     const Being *const being = actorManager->findBeingByName(
         name, ActorType::Player);
-    if (!being)
+    if (being == nullptr)
         return;
     createOutPacket(CMSG_PARTY_CHANGE_LEADER);
     outMsg.writeBeingId(being->getId(), "account id");
diff --git a/src/net/eathena/partyrecv.cpp b/src/net/eathena/partyrecv.cpp
index 2a0b7476a..0947a525e 100644
--- a/src/net/eathena/partyrecv.cpp
+++ b/src/net/eathena/partyrecv.cpp
@@ -66,13 +66,13 @@ void PartyRecv::processPartyMemberInfo(Net::MessageIn &msg)
     msg.readInt8("pickup item share (&1)");
     msg.readInt8("get item share (&2)");
 
-    if (!Ea::taParty)
+    if (Ea::taParty == nullptr)
         return;
 
     PartyMember *const member = Ea::taParty->addMember(id, nick);
-    if (member)
+    if (member != nullptr)
     {
-        if (partyTab && member->getOnline() != online)
+        if ((partyTab != nullptr) && member->getOnline() != online)
             partyTab->showOnline(nick, fromBool(online, Online));
         member->setLeader(leader);
         member->setOnline(online);
@@ -84,9 +84,9 @@ void PartyRecv::processPartyMemberInfo(Net::MessageIn &msg)
 
 void PartyRecv::processPartySettings(Net::MessageIn &msg)
 {
-    if (!partyTab)
+    if (partyTab == nullptr)
     {
-        if (!chatWindow)
+        if (chatWindow == nullptr)
             return;
 
         Ea::PartyRecv::createTab();
@@ -111,15 +111,15 @@ void PartyRecv::processPartyInfo(Net::MessageIn &msg)
     bool isOldParty = false;
     std::set<std::string> names;
     std::set<std::string> onlineNames;
-    if (!Ea::taParty)
+    if (Ea::taParty == nullptr)
     {
         logger->log1("error: party empty in SMSG_PARTY_INFO");
         Ea::taParty = Party::getParty(1);
     }
-    if (!partyTab)
+    if (partyTab == nullptr)
         Ea::PartyRecv::createTab();
 
-    if (Ea::taParty)
+    if (Ea::taParty != nullptr)
     {
         if (Ea::taParty->getNumberOfElements() > 1)
         {
@@ -131,24 +131,24 @@ void PartyRecv::processPartyInfo(Net::MessageIn &msg)
                 if ((*it)->getOnline())
                     onlineNames.insert((*it)->getName());
             }
-            if (localPlayer)
+            if (localPlayer != nullptr)
                 onlineNames.insert(localPlayer->getName());
         }
     }
 
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         logger->log1("error: localPlayer==0 in SMSG_PARTY_INFO");
 
-    if (Ea::taParty)
+    if (Ea::taParty != nullptr)
         Ea::taParty->clearMembers();
 
     const int length = msg.readInt16("len");
     const std::string name = msg.readString(24, "party name");
-    if (Ea::taParty)
+    if (Ea::taParty != nullptr)
         Ea::taParty->setName(name);
 
     const int count = (length - 28) / 46;
-    if (localPlayer && Ea::taParty)
+    if ((localPlayer != nullptr) && (Ea::taParty != nullptr))
     {
         localPlayer->setParty(Ea::taParty);
         localPlayer->setPartyName(Ea::taParty->getName());
@@ -162,7 +162,7 @@ void PartyRecv::processPartyInfo(Net::MessageIn &msg)
         const bool leader = msg.readUInt8("leader") == 0U;
         const bool online = msg.readUInt8("online") == 0U;
 
-        if (Ea::taParty)
+        if (Ea::taParty != nullptr)
         {
             bool joined(false);
 
@@ -176,9 +176,9 @@ void PartyRecv::processPartyInfo(Net::MessageIn &msg)
                 }
             }
             PartyMember *const member = Ea::taParty->addMember(id, nick);
-            if (member)
+            if (member != nullptr)
             {
-                if (!joined && partyTab)
+                if (!joined && (partyTab != nullptr))
                 {
                     if (!names.empty() && ((onlineNames.find(nick)
                         == onlineNames.end() && online)
@@ -202,14 +202,14 @@ void PartyRecv::processPartyInfo(Net::MessageIn &msg)
         }
     }
 
-    if (Ea::taParty)
+    if (Ea::taParty != nullptr)
         Ea::taParty->sort();
 
-    if (localPlayer && Ea::taParty)
+    if ((localPlayer != nullptr) && (Ea::taParty != nullptr))
     {
         localPlayer->setParty(Ea::taParty);
         localPlayer->setPartyName(Ea::taParty->getName());
-        if (socialWindow)
+        if (socialWindow != nullptr)
             socialWindow->updateParty();
     }
 }
@@ -227,10 +227,10 @@ void PartyRecv::processPartyMessage(Net::MessageIn &msg)
     if (pos != std::string::npos)
         chatMsg.erase(0, pos + 3);
 
-    if (Ea::taParty && partyTab)
+    if ((Ea::taParty != nullptr) && (partyTab != nullptr))
     {
         const PartyMember *const member = Ea::taParty->getMember(id);
-        if (member)
+        if (member != nullptr)
         {
             partyTab->chatLog(member->getName(), chatMsg);
         }
@@ -244,7 +244,7 @@ void PartyRecv::processPartyMessage(Net::MessageIn &msg)
 
 void PartyRecv::processPartyInviteResponse(Net::MessageIn &msg)
 {
-    if (!partyTab)
+    if (partyTab == nullptr)
         return;
 
     const std::string nick = msg.readString(24, "nick");
@@ -307,9 +307,9 @@ void PartyRecv::processPartyLeader(Net::MessageIn &msg)
         msg.readBeingId("old leder id"));
     PartyMember *const newMember = Ea::taParty->getMember(
         msg.readBeingId("new leder id"));
-    if (oldMember)
+    if (oldMember != nullptr)
         oldMember->setLeader(false);
-    if (newMember)
+    if (newMember != nullptr)
         newMember->setLeader(true);
 }
 
@@ -318,7 +318,7 @@ void PartyRecv::processPartyInvited(Net::MessageIn &msg)
     const int id = msg.readInt32("party id");
     const std::string partyName = msg.readString(24, "party name");
 
-    if (socialWindow)
+    if (socialWindow != nullptr)
         socialWindow->showPartyInvite(partyName, std::string(), id);
 }
 
diff --git a/src/net/eathena/pethandler.cpp b/src/net/eathena/pethandler.cpp
index a7062b21b..602f9cd88 100644
--- a/src/net/eathena/pethandler.cpp
+++ b/src/net/eathena/pethandler.cpp
@@ -58,7 +58,7 @@ void PetHandler::emote(const uint8_t emoteId)
 
 void PetHandler::catchPet(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_PET_CATCH);
diff --git a/src/net/eathena/petrecv.cpp b/src/net/eathena/petrecv.cpp
index 50bf43eed..f2cf65a28 100644
--- a/src/net/eathena/petrecv.cpp
+++ b/src/net/eathena/petrecv.cpp
@@ -74,7 +74,7 @@ void PetRecv::processEggsList(Net::MessageIn &msg)
 {
     const int count = (msg.readInt16("len") - 4) / 2;
     const Inventory *const inv = PlayerInfo::getInventory();
-    if (!inv)
+    if (inv == nullptr)
         return;
     menu = MenuType::Eggs;
 
@@ -92,7 +92,7 @@ void PetRecv::processEggsList(Net::MessageIn &msg)
         const int index = msg.readInt16("index") - INVENTORY_OFFSET;
         const Item *const item = inv->getItem(index);
 
-        if (item)
+        if (item != nullptr)
             dialog->addItem(item, 0);
     }
 }
@@ -103,7 +103,7 @@ void PetRecv::processPetData(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("pet id");
     Being *const dstBeing = actorManager->findBeing(id);
     const int data = msg.readInt32("data");
-    if (!cmd)  // pre init
+    if (cmd == 0)  // pre init
     {
         PetInfo *const info = new PetInfo;
         info->id = id;
@@ -112,7 +112,7 @@ void PetRecv::processPetData(Net::MessageIn &msg)
         return;
     }
     PetInfo *const info = PlayerInfo::getPet();
-    if (!info)
+    if (info == nullptr)
         return;
     switch (cmd)
     {
@@ -150,7 +150,7 @@ void PetRecv::processPetStatus(Net::MessageIn &msg)
 //        being->setLevel(level);
 
     PetInfo *const info = PlayerInfo::getPet();
-    if (!info)
+    if (info == nullptr)
         return;
     info->name = name;
     info->level = level;
@@ -167,7 +167,7 @@ void PetRecv::processPetFood(Net::MessageIn &msg)
 {
     const int result = msg.readUInt8("result");
     msg.readInt16("food id");
-    if (result)
+    if (result != 0)
         NotifyManager::notify(NotifyTypes::PET_FEED_OK);
     else
         NotifyManager::notify(NotifyTypes::PET_FEED_ERROR);
diff --git a/src/net/eathena/playerhandler.cpp b/src/net/eathena/playerhandler.cpp
index 818fffde9..ef7afa6e4 100644
--- a/src/net/eathena/playerhandler.cpp
+++ b/src/net/eathena/playerhandler.cpp
@@ -101,7 +101,7 @@ void PlayerHandler::increaseSkill(const uint16_t skillId) const
 
 void PlayerHandler::pickUp(const FloorItem *const floorItem) const
 {
-    if (!floorItem)
+    if (floorItem == nullptr)
         return;
 
     createOutPacket(CMSG_ITEM_PICKUP);
@@ -203,7 +203,7 @@ void PlayerHandler::pickUp(const FloorItem *const floorItem) const
 
     EAthena::InventoryHandler *const handler =
         static_cast<EAthena::InventoryHandler*>(inventoryHandler);
-    if (handler)
+    if (handler != nullptr)
         handler->pushPickup(floorItem->getId());
 }
 
@@ -543,11 +543,11 @@ void PlayerHandler::setStat(Net::MessageIn &msg,
             break;
         case Sp::HP:
             PlayerInfo::setAttribute(Attributes::PLAYER_HP, base);
-            if (localPlayer->isInParty() && Party::getParty(1))
+            if (localPlayer->isInParty() && (Party::getParty(1) != nullptr))
             {
                 PartyMember *const m = Party::getParty(1)
                     ->getMember(localPlayer->getId());
-                if (m)
+                if (m != nullptr)
                 {
                     m->setHp(base);
                     m->setMaxHp(PlayerInfo::getAttribute(
@@ -558,11 +558,11 @@ void PlayerHandler::setStat(Net::MessageIn &msg,
         case Sp::MAXHP:
             PlayerInfo::setAttribute(Attributes::PLAYER_MAX_HP, base);
 
-            if (localPlayer->isInParty() && Party::getParty(1))
+            if (localPlayer->isInParty() && (Party::getParty(1) != nullptr))
             {
                 PartyMember *const m = Party::getParty(1)->getMember(
                     localPlayer->getId());
-                if (m)
+                if (m != nullptr)
                 {
                     m->setHp(PlayerInfo::getAttribute(Attributes::PLAYER_HP));
                     m->setMaxHp(base);
@@ -580,7 +580,7 @@ void PlayerHandler::setStat(Net::MessageIn &msg,
             break;
         case Sp::BASELEVEL:
             PlayerInfo::setAttribute(Attributes::PLAYER_LEVEL, base);
-            if (localPlayer)
+            if (localPlayer != nullptr)
             {
                 localPlayer->setLevel(base);
                 localPlayer->updateName();
@@ -588,7 +588,7 @@ void PlayerHandler::setStat(Net::MessageIn &msg,
             break;
         case Sp::SKILLPOINT:
             PlayerInfo::setAttribute(Attributes::PLAYER_SKILL_POINTS, base);
-            if (skillDialog)
+            if (skillDialog != nullptr)
                 skillDialog->update();
             break;
         case Sp::STR:
diff --git a/src/net/eathena/playerrecv.cpp b/src/net/eathena/playerrecv.cpp
index 36ee19018..9eb57b687 100644
--- a/src/net/eathena/playerrecv.cpp
+++ b/src/net/eathena/playerrecv.cpp
@@ -79,7 +79,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     unsigned int val = msg.readUInt8("str");
     PlayerInfo::setStatBase(Attributes::PLAYER_STR, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_STR,
             msg.readUInt8("str cost"));
@@ -91,7 +91,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     val = msg.readUInt8("agi");
     PlayerInfo::setStatBase(Attributes::PLAYER_AGI, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_AGI,
             msg.readUInt8("agi cost"));
@@ -103,7 +103,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     val = msg.readUInt8("vit");
     PlayerInfo::setStatBase(Attributes::PLAYER_VIT, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_VIT,
             msg.readUInt8("vit cost"));
@@ -115,7 +115,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     val = msg.readUInt8("int");
     PlayerInfo::setStatBase(Attributes::PLAYER_INT, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_INT,
             msg.readUInt8("int cost"));
@@ -127,7 +127,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     val = msg.readUInt8("dex");
     PlayerInfo::setStatBase(Attributes::PLAYER_DEX, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_DEX,
             msg.readUInt8("dex cost"));
@@ -139,7 +139,7 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
     val = msg.readUInt8("luk");
     PlayerInfo::setStatBase(Attributes::PLAYER_LUK, val);
-    if (statusWindow)
+    if (statusWindow != nullptr)
     {
         statusWindow->setPointsNeeded(Attributes::PLAYER_LUK,
             msg.readUInt8("luk cost"));
@@ -191,12 +191,12 @@ void PlayerRecv::processPlayerStatUpdate5(Net::MessageIn &msg)
 
 void PlayerRecv::processPlayerGetExp(Net::MessageIn &msg)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
     const BeingId id = msg.readBeingId("player id");
     const int exp = msg.readInt32("exp amount");
     const int stat = msg.readInt16("exp type");
-    const bool fromQuest = msg.readInt16("is from quest");
+    const bool fromQuest = msg.readInt16("is from quest") != 0;
     if (!fromQuest && id == localPlayer->getId())
     {
         if (stat == 1)
@@ -221,7 +221,7 @@ void PlayerRecv::processWalkResponse(Net::MessageIn &msg)
     msg.readInt32("tick");
     msg.readCoordinatePair(srcX, srcY, dstX, dstY, "move path");
     msg.readUInt8("(sx<<4) | (sy&0x0f)");
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->setRealPos(dstX, dstY);
     BLOCK_END("PlayerRecv::processWalkResponse")
 }
@@ -231,7 +231,7 @@ void PlayerRecv::processWalkError(Net::MessageIn &msg)
     msg.readInt32("tick");
     const int x = msg.readInt16("x");
     const int y = msg.readInt16("y");
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->failMove(x, y);
 }
 
@@ -247,7 +247,7 @@ void PlayerRecv::processPvpInfo(Net::MessageIn &msg)
 
 void PlayerRecv::processPlayerHeal(Net::MessageIn &msg)
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     const int type = msg.readInt16("var id");
@@ -261,11 +261,11 @@ void PlayerRecv::processPlayerHeal(Net::MessageIn &msg)
         const int base = PlayerInfo::getAttribute(Attributes::PLAYER_HP) +
             amount;
         PlayerInfo::setAttribute(Attributes::PLAYER_HP, base);
-        if (localPlayer->isInParty() && Party::getParty(1))
+        if (localPlayer->isInParty() && (Party::getParty(1) != nullptr))
         {
             PartyMember *const m = Party::getParty(1)
                 ->getMember(localPlayer->getId());
-            if (m)
+            if (m != nullptr)
             {
                 m->setHp(base);
                 m->setMaxHp(PlayerInfo::getAttribute(
@@ -390,23 +390,23 @@ void PlayerRecv::processPlayerRankPoints(Net::MessageIn &msg)
 
 void PlayerRecv::processOnlineList(Net::MessageIn &msg)
 {
-    if (!whoIsOnline)
+    if (whoIsOnline == nullptr)
         return;
 
     BLOCK_START("PlayerRecv::processOnlineList")
     const int size = msg.readInt16("len") - 4;
     std::vector<OnlinePlayer*> arr;
 
-    if (!size)
+    if (size == 0)
     {
-        if (whoIsOnline)
+        if (whoIsOnline != nullptr)
             whoIsOnline->loadList(arr);
         BLOCK_END("PlayerRecv::processOnlineList")
         return;
     }
 
     char *const start = reinterpret_cast<char*>(msg.readBytes(size, "nicks"));
-    if (!start)
+    if (start == nullptr)
     {
         BLOCK_END("PlayerRecv::processOnlineList")
         return;
@@ -417,7 +417,7 @@ void PlayerRecv::processOnlineList(Net::MessageIn &msg)
     int addVal = 3;
 
     while (buf - start + 1 < size
-           && *(buf + CAST_SIZE(addVal)))
+           && (*(buf + CAST_SIZE(addVal)) != 0))
     {
         const unsigned char status = *buf;
         buf ++;
@@ -429,9 +429,9 @@ void PlayerRecv::processOnlineList(Net::MessageIn &msg)
         GenderT gender = Gender::UNSPECIFIED;
         if (config.getBoolValue("showgender"))
         {
-            if (status & BeingFlag::GENDER_MALE)
+            if ((status & BeingFlag::GENDER_MALE) != 0)
                 gender = Gender::MALE;
-            else if (status & BeingFlag::GENDER_OTHER)
+            else if ((status & BeingFlag::GENDER_OTHER) != 0)
                 gender = Gender::OTHER;
             else
                 gender = Gender::FEMALE;
@@ -441,7 +441,7 @@ void PlayerRecv::processOnlineList(Net::MessageIn &msg)
         buf += strlen(buf) + 1;
     }
 
-    if (whoIsOnline)
+    if (whoIsOnline != nullptr)
         whoIsOnline->loadList(arr);
     delete [] start;
     BLOCK_END("PlayerRecv::processOnlineList")
@@ -466,7 +466,7 @@ void PlayerRecv::processKilledBy(Net::MessageIn &msg)
     else
     {
         std::string name;
-        if (dstBeing)
+        if (dstBeing != nullptr)
             name = dstBeing->getName();
         else
             name = strprintf("?%u", CAST_U32(id));
diff --git a/src/net/eathena/questrecv.cpp b/src/net/eathena/questrecv.cpp
index 19ba546a3..69ad93541 100644
--- a/src/net/eathena/questrecv.cpp
+++ b/src/net/eathena/questrecv.cpp
@@ -49,12 +49,12 @@ void QuestRecv::processAddQuest(Net::MessageIn &msg)
 
     msg.skipToEnd("unused");
 
-    if (questsWindow)
+    if (questsWindow != nullptr)
     {
         questsWindow->updateQuest(var, val, 0, 0, 0);
         questsWindow->rebuild(true);
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->updateQuest(var, val, 0, 0, 0);
         skillDialog->playUpdateEffect(var + SKILL_VAR_MIN_ID);
@@ -70,12 +70,12 @@ void QuestRecv::processAddQuest2(Net::MessageIn &msg)
     const int val3 = msg.readInt32("count3");
     const int time = msg.readInt32("time");
 
-    if (questsWindow)
+    if (questsWindow != nullptr)
     {
         questsWindow->updateQuest(var, val1, val2, val3, time);
         questsWindow->rebuild(true);
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->updateQuest(var, val1, val2, val3, time);
         skillDialog->playUpdateEffect(var + SKILL_VAR_MIN_ID);
@@ -96,13 +96,13 @@ void QuestRecv::processAddQuests(Net::MessageIn &msg)
             msg.readInt32("time");
             msg.readInt16("objectives count");
         }
-        if (questsWindow)
+        if (questsWindow != nullptr)
             questsWindow->updateQuest(var, val, 0, 0, 0);
-        if (skillDialog)
+        if (skillDialog != nullptr)
             skillDialog->updateQuest(var, val, 0, 0, 0);
     }
 
-    if (questsWindow)
+    if (questsWindow != nullptr)
         questsWindow->rebuild(false);
 }
 
@@ -118,13 +118,13 @@ void QuestRecv::processAddQuests2(Net::MessageIn &msg)
         const int val2 = msg.readInt32("count2");
         const int val3 = msg.readInt32("count3");
         const int time = msg.readInt32("time");
-        if (questsWindow)
+        if (questsWindow != nullptr)
             questsWindow->updateQuest(var, val1, val2, val3, time);
-        if (skillDialog)
+        if (skillDialog != nullptr)
             skillDialog->updateQuest(var, val1, val2, val3, time);
     }
 
-    if (questsWindow)
+    if (questsWindow != nullptr)
         questsWindow->rebuild(false);
 }
 
@@ -170,12 +170,12 @@ void QuestRecv::processRemoveQuest(Net::MessageIn &msg)
 
     // not removing quest, because this is impossible,
     // but changing status to -1
-    if (questsWindow)
+    if (questsWindow != nullptr)
     {
         questsWindow->updateQuest(var, val, 0, 0, 0);
         questsWindow->rebuild(true);
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->updateQuest(var, val, 0, 0, 0);
         skillDialog->playUpdateEffect(var + SKILL_VAR_MIN_ID);
diff --git a/src/net/eathena/skillrecv.cpp b/src/net/eathena/skillrecv.cpp
index a7db7fa29..e4b71a076 100644
--- a/src/net/eathena/skillrecv.cpp
+++ b/src/net/eathena/skillrecv.cpp
@@ -71,7 +71,7 @@ void SkillRecv::processPlayerSkills(Net::MessageIn &msg)
     const int skillCount = (msg.getLength() - 4) / sz;
     int updateSkill = 0;
 
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->hideSkills(SkillOwner::Player);
     for (int k = 0; k < skillCount; k++)
     {
@@ -86,10 +86,10 @@ void SkillRecv::processPlayerSkills(Net::MessageIn &msg)
         const std::string name = msg.readString(24, "skill name");
         const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
         const int oldLevel = PlayerInfo::getSkillLevel(skillId);
-        if (oldLevel && oldLevel != level)
+        if ((oldLevel != 0) && oldLevel != level)
             updateSkill = skillId;
         PlayerInfo::setSkillLevel(skillId, level);
-        if (skillDialog)
+        if (skillDialog != nullptr)
         {
             if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
             {
@@ -98,10 +98,10 @@ void SkillRecv::processPlayerSkills(Net::MessageIn &msg)
             }
         }
     }
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playUpdateEffect(updateSkill);
     }
 }
@@ -118,10 +118,10 @@ void SkillRecv::processSkillAdd(Net::MessageIn &msg)
     const std::string name = msg.readString(24, "skill name");
     const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
     const int oldLevel = PlayerInfo::getSkillLevel(skillId);
-    if (oldLevel && oldLevel != level)
+    if ((oldLevel != 0) && oldLevel != level)
         updateSkill = skillId;
     PlayerInfo::setSkillLevel(skillId, level);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
         {
@@ -129,7 +129,7 @@ void SkillRecv::processSkillAdd(Net::MessageIn &msg)
                 skillId, name, level, range, up, inf, sp);
         }
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playUpdateEffect(updateSkill);
     }
 }
@@ -148,10 +148,10 @@ void SkillRecv::processSkillAdd2(Net::MessageIn &msg)
     const std::string name = msg.readString(24, "skill name");
     const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
     const int oldLevel = PlayerInfo::getSkillLevel(skillId);
-    if (oldLevel && oldLevel != level)
+    if ((oldLevel != 0) && oldLevel != level)
         updateSkill = skillId;
     PlayerInfo::setSkillLevel(skillId, level);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
         {
@@ -159,7 +159,7 @@ void SkillRecv::processSkillAdd2(Net::MessageIn &msg)
                 skillId, name, level, range, up, inf, sp);
         }
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playUpdateEffect(updateSkill);
     }
 }
@@ -175,10 +175,10 @@ void SkillRecv::processSkillUpdate(Net::MessageIn &msg)
     const int range = msg.readInt16("range");
     const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
     const int oldLevel = PlayerInfo::getSkillLevel(skillId);
-    if (oldLevel && oldLevel != level)
+    if ((oldLevel != 0) && oldLevel != level)
         updateSkill = skillId;
     PlayerInfo::setSkillLevel(skillId, level);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
         {
@@ -186,7 +186,7 @@ void SkillRecv::processSkillUpdate(Net::MessageIn &msg)
                 skillId, "", level, range, up, inf, sp);
         }
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playUpdateEffect(updateSkill);
     }
 }
@@ -204,10 +204,10 @@ void SkillRecv::processSkillUpdate2(Net::MessageIn &msg)
     const int range = msg.readInt16("range");
     const Modifiable up = fromBool(msg.readUInt8("up flag"), Modifiable);
     const int oldLevel = PlayerInfo::getSkillLevel(skillId);
-    if (oldLevel && oldLevel != level)
+    if ((oldLevel != 0) && oldLevel != level)
         updateSkill = skillId;
     PlayerInfo::setSkillLevel(skillId, level);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         if (!skillDialog->updateSkill(skillId, range, up, inf, sp))
         {
@@ -215,7 +215,7 @@ void SkillRecv::processSkillUpdate2(Net::MessageIn &msg)
                 skillId, "", level, range, up, inf, sp);
         }
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playUpdateEffect(updateSkill);
     }
 }
@@ -228,11 +228,11 @@ void SkillRecv::processSkillDelete(Net::MessageIn &msg)
     if (oldLevel != 0)
         updateSkill = skillId;
     PlayerInfo::setSkillLevel(skillId, 0);
-    if (skillDialog)
+    if (skillDialog != nullptr)
     {
         skillDialog->removeSkill(skillId);
         skillDialog->update();
-        if (updateSkill)
+        if (updateSkill != 0)
             skillDialog->playRemoveEffect(updateSkill);
     }
 }
@@ -241,7 +241,7 @@ void SkillRecv::processSkillCoolDown(Net::MessageIn &msg)
 {
     const int skillId = msg.readInt16("skill id");
     const int duration = msg.readInt32("duration");
-    if (skillDialog)
+    if (skillDialog != nullptr)
         skillDialog->setSkillDuration(SkillOwner::Player, skillId, duration);
 }
 
@@ -259,7 +259,7 @@ void SkillRecv::processSkillCoolDownList(Net::MessageIn &msg)
         if (msg.getVersion() >= 20120604)
             msg.readInt32("total");
         const int duration = msg.readInt32("duration");
-        if (skillDialog)
+        if (skillDialog != nullptr)
         {
             skillDialog->setSkillDuration(SkillOwner::Player,
                 skillId, duration);
@@ -281,19 +281,19 @@ void SkillRecv::processSkillFailed(Net::MessageIn &msg)
         logger->log("Action: %d/%d", bskill, success);
     }
 
-    if (localPlayer)
+    if (localPlayer != nullptr)
         localPlayer->stopCast(true);
     std::string txt;
     if (success == CAST_S32(SKILL_FAILED) && bskill != 0)
     {
-        if (localPlayer && bskill == CAST_S32(BSKILL_EMOTE)
+        if ((localPlayer != nullptr) && bskill == CAST_S32(BSKILL_EMOTE)
             && reason == CAST_S32(RFAIL_SKILLDEP))
         {
             localPlayer->stopAdvert();
         }
 
         const SkillInfo *const info = skillDialog->getSkill(bskill);
-        if (info)
+        if (info != nullptr)
         {
             txt = info->errorText;
         }
@@ -306,7 +306,7 @@ void SkillRecv::processSkillFailed(Net::MessageIn &msg)
     else
     {
         const SkillInfo *const info = skillDialog->getSkill(skillId);
-        if (info)
+        if (info != nullptr)
         {
             txt = info->errorText + ".";
         }
diff --git a/src/net/eathena/tradehandler.cpp b/src/net/eathena/tradehandler.cpp
index 9db89dae4..65cb72cc8 100644
--- a/src/net/eathena/tradehandler.cpp
+++ b/src/net/eathena/tradehandler.cpp
@@ -48,7 +48,7 @@ TradeHandler::TradeHandler() :
 
 void TradeHandler::request(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_TRADE_REQUEST);
@@ -66,7 +66,7 @@ void TradeHandler::respond(const bool accept) const
 
 void TradeHandler::addItem(const Item *const item, const int amount) const
 {
-    if (!item)
+    if (item == nullptr)
         return;
 
     TradeRecv::mItemIndex = item->getInvIndex();
diff --git a/src/net/eathena/traderecv.cpp b/src/net/eathena/traderecv.cpp
index 2dcacc609..ac64d4fb0 100644
--- a/src/net/eathena/traderecv.cpp
+++ b/src/net/eathena/traderecv.cpp
@@ -101,7 +101,7 @@ void TradeRecv::processTradeItemAdd(Net::MessageIn &msg)
         }
     }
 
-    if (tradeWindow)
+    if (tradeWindow != nullptr)
     {
         if (type == 0)
         {
@@ -138,9 +138,9 @@ void TradeRecv::processTradeItemAddResponse(Net::MessageIn &msg)
         {
             Item *const item = PlayerInfo::getInventory()->getItem(
                 mItemIndex);
-            if (!item)
+            if (item == nullptr)
                 return;
-            if (tradeWindow)
+            if (tradeWindow != nullptr)
             {
                 tradeWindow->addItem2(item->getId(),
                     item->getType(),
diff --git a/src/net/eathena/updateprotocol.cpp b/src/net/eathena/updateprotocol.cpp
index 43b65c80c..afe25b874 100644
--- a/src/net/eathena/updateprotocol.cpp
+++ b/src/net/eathena/updateprotocol.cpp
@@ -41,7 +41,7 @@ void updateProtocol()
 #include "net/eathena/packetsout.inc"
 #undef packet
     Network *const network = Network::mInstance;
-    if (network)
+    if (network != nullptr)
     {
         network->clearHandlers();
         network->registerHandlers();
diff --git a/src/net/eathena/vendinghandler.cpp b/src/net/eathena/vendinghandler.cpp
index 307018680..e9d0643a3 100644
--- a/src/net/eathena/vendinghandler.cpp
+++ b/src/net/eathena/vendinghandler.cpp
@@ -52,7 +52,7 @@ void VendingHandler::close() const
 
 void VendingHandler::open(const Being *const being) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_VENDING_LIST_REQ);
@@ -63,7 +63,7 @@ void VendingHandler::buy(const Being *const being,
                          const int index,
                          const int amount) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_VENDING_BUY);
@@ -83,7 +83,7 @@ void VendingHandler::buyItems(const Being *const being,
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         cnt ++;
     }
@@ -98,7 +98,7 @@ void VendingHandler::buyItems(const Being *const being,
     {
         ShopItem *const item = *it;
         const int usedQuantity = item->getUsedQuantity();
-        if (!usedQuantity)
+        if (usedQuantity == 0)
             continue;
         item->increaseQuantity(usedQuantity);
         item->increaseUsedQuantity(-usedQuantity);
@@ -113,7 +113,7 @@ void VendingHandler::buy2(const Being *const being,
                           const int index,
                           const int amount) const
 {
-    if (!being)
+    if (being == nullptr)
         return;
 
     createOutPacket(CMSG_VENDING_BUY2);
diff --git a/src/net/eathena/vendingrecv.cpp b/src/net/eathena/vendingrecv.cpp
index bf0cd20eb..23d4843f1 100644
--- a/src/net/eathena/vendingrecv.cpp
+++ b/src/net/eathena/vendingrecv.cpp
@@ -77,7 +77,7 @@ void VendingRecv::processShowBoard(Net::MessageIn &msg)
     const BeingId id = msg.readBeingId("owner id");
     const std::string shopName = msg.readString(80, "shop name");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setSellBoard(shopName);
 }
 
@@ -85,7 +85,7 @@ void VendingRecv::processHideBoard(Net::MessageIn &msg)
 {
     const BeingId id = msg.readBeingId("owner id");
     Being *const dstBeing = actorManager->findBeing(id);
-    if (dstBeing)
+    if (dstBeing != nullptr)
         dstBeing->setSellBoard(std::string());
     if (dstBeing == localPlayer)
     {
@@ -106,7 +106,7 @@ void VendingRecv::processItemsList(Net::MessageIn &msg)
     const int count = (msg.readInt16("len") - offset) / packetLen;
     const BeingId id = msg.readBeingId("id");
     const Being *const being = actorManager->findBeing(id);
-    if (!being)
+    if (being == nullptr)
         return;
     int cards[maxCards];
     CREATEWIDGETV(mBuyDialog, BuyDialog, being, DEFAULT_CURRENCY);
@@ -142,7 +142,7 @@ void VendingRecv::processItemsList(Net::MessageIn &msg)
         const ItemColor color = ItemColorManager::getColorFromCards(&cards[0]);
         ShopItem *const item = mBuyDialog->addItem(itemId, type,
             color, amount, value);
-        if (item)
+        if (item != nullptr)
         {
             item->setInvIndex(index);
             item->setOptions(options);
@@ -230,10 +230,10 @@ void VendingRecv::processReport(Net::MessageIn &msg)
         money = msg.readInt32("zeny");
     }
     const Inventory *const inventory = PlayerInfo::getCartInventory();
-    if (!inventory)
+    if (inventory == nullptr)
         return;
     const Item *const item = inventory->getItem(index);
-    if (!item)
+    if (item == nullptr)
         return;
 
     const ItemInfo &info = item->getInfo();