diff --git a/Source/monstdat.cpp b/Source/monstdat.cpp
index e39a6a452..83689353f 100644
--- a/Source/monstdat.cpp
+++ b/Source/monstdat.cpp
@@ -487,7 +487,7 @@ void LoadMonstDat()
 			const auto [it, inserted] = spritePathToId.emplace(assetsSuffix, spritePathToId.size());
 			if (inserted)
 				MonsterSpritePaths.push_back(it->first);
-			monster.spriteId = it->second;
+			monster.spriteId = static_cast<uint16_t>(it->second);
 		}
 		reader.readString("soundSuffix", monster.soundSuffix);
 		reader.readString("trnFile", monster.trnFile);
diff --git a/Source/monster.cpp b/Source/monster.cpp
index 303b2b70a..f8b1ca813 100644
--- a/Source/monster.cpp
+++ b/Source/monster.cpp
@@ -141,7 +141,7 @@ void InitMonster(Monster &monster, Direction rd, size_t typeIndex, Point positio
 	monster.position.tile = position;
 	monster.position.future = position;
 	monster.position.old = position;
-	monster.levelType = typeIndex;
+	monster.levelType = static_cast<uint8_t>(typeIndex);
 	monster.mode = MonsterMode::Stand;
 	monster.animInfo = {};
 	monster.changeAnimationData(MonsterGraphic::Stand);
@@ -231,7 +231,7 @@ bool CanPlaceMonster(Point position)
 	    && !IsTileOccupied(position);
 }
 
-void PlaceMonster(int i, size_t typeIndex, Point position)
+void PlaceMonster(size_t i, size_t typeIndex, Point position)
 {
 	if (LevelMonsterTypes[typeIndex].type == MT_NAKRUL) {
 		for (size_t j = 0; j < ActiveMonsterCount; j++) {
@@ -247,9 +247,9 @@ void PlaceMonster(int i, size_t typeIndex, Point position)
 	InitMonster(monster, rd, typeIndex, position);
 }
 
-void PlaceGroup(size_t typeIndex, unsigned num, Monster *leader = nullptr, bool leashed = false)
+void PlaceGroup(size_t typeIndex, size_t num, Monster *leader = nullptr, bool leashed = false)
 {
-	unsigned placed = 0;
+	uint8_t placed = 0;
 
 	for (int try1 = 0; try1 < 10; try1++) {
 		while (placed != 0) {
@@ -1122,7 +1122,7 @@ void MonsterAttackMonster(Monster &attacker, Monster &target, int hper, int mind
 	ApplyMonsterDamage(DamageType::Physical, target, dam);
 
 	if (attacker.isPlayerMinion()) {
-		int playerId = attacker.getId();
+		size_t playerId = attacker.getId();
 		const Player &player = Players[playerId];
 		target.tag(player);
 	}
@@ -1573,7 +1573,7 @@ void MonsterPetrified(Monster &monster)
 
 Monster *AddSkeleton(Point position, Direction dir, bool inMap)
 {
-	size_t typeCount = 0;
+	int32_t typeCount = 0;
 	size_t skeletonIndexes[SkeletonTypes.size()];
 	for (size_t i = 0; i < LevelMonsterTypeCount; i++) {
 		if (IsSkel(LevelMonsterTypes[i].type)) {
@@ -2892,7 +2892,7 @@ void LachdananAi(Monster &monster)
 				NetSendCmdQuest(true, Quests[Q_VEIL]);
 				MonsterDeath(monster, monster.direction, true);
 				delta_kill_monster(monster, monster.position.tile, *MyPlayer);
-				NetSendCmdLocParam1(false, CMD_MONSTDEATH, monster.position.tile, monster.getId());
+				NetSendCmdLocParam1(false, CMD_MONSTDEATH, monster.position.tile, static_cast<uint16_t>(monster.getId()));
 			}
 		}
 	}
@@ -3148,11 +3148,11 @@ MonsterSpritesData LoadMonsterSpritesData(const MonsterData &monsterData)
 		clxData.emplace_back();
 		Cl2ToClx(reinterpret_cast<uint8_t *>(&result.data[begin]), end - begin,
 		    PointerOrValue<uint16_t> { monsterData.width }, clxData.back());
-		result.offsets[j] = accumulatedSize;
+		result.offsets[j] = static_cast<uint32_t>(accumulatedSize);
 		accumulatedSize += clxData.back().size();
 		++j;
 	}
-	result.offsets[clxData.size()] = accumulatedSize;
+	result.offsets[clxData.size()] = static_cast<uint32_t>(accumulatedSize);
 	result.data = nullptr;
 	result.data = std::unique_ptr<std::byte[]>(new std::byte[accumulatedSize]);
 	for (size_t i = 0; i < clxData.size(); ++i) {
@@ -3278,7 +3278,7 @@ void InitLevelMonsters()
 	totalmonsters = MaxMonsters;
 
 	for (size_t i = 0; i < MaxMonsters; i++) {
-		ActiveMonsters[i] = i;
+		ActiveMonsters[i] = static_cast<int>(i);
 	}
 
 	uniquetrans = 0;
@@ -3474,13 +3474,13 @@ void InitAllMonsterGFX()
 	if (HeadlessMode)
 		return;
 
-	using LevelMonsterTypeIndices = StaticVector<uint8_t, 8>;
+	using LevelMonsterTypeIndices = StaticVector<size_t, 8>;
 	std::vector<LevelMonsterTypeIndices> monstersBySprite(GetNumMonsterSprites());
 	for (size_t i = 0; i < LevelMonsterTypeCount; ++i) {
 		monstersBySprite[static_cast<size_t>(LevelMonsterTypes[i].data().spriteId)].emplace_back(i);
 	}
-	uint32_t totalUniqueBytes = 0;
-	uint32_t totalBytes = 0;
+	size_t totalUniqueBytes = 0;
+	size_t totalBytes = 0;
 	for (const LevelMonsterTypeIndices &monsterTypes : monstersBySprite) {
 		if (monsterTypes.empty())
 			continue;
@@ -3543,14 +3543,14 @@ void InitMonsters()
 	if (!setlevel) {
 		if (!gbIsSpawn)
 			PlaceUniqueMonsters();
-		int na = 0;
+		size_t na = 0;
 		for (int s = 16; s < 96; s++) {
 			for (int t = 16; t < 96; t++) {
 				if (!IsTileSolid({ s, t }))
 					na++;
 			}
 		}
-		int numplacemonsters = na / 30;
+		size_t numplacemonsters = na / 30;
 		if (gbIsMultiplayer)
 			numplacemonsters += numplacemonsters / 2;
 		if (ActiveMonsterCount + numplacemonsters > MaxMonsters - 10)
@@ -3657,12 +3657,12 @@ void ApplyMonsterDamage(DamageType damageType, Monster &monster, int damage)
 
 	if (monster.hitPoints >> 6 <= 0) {
 		delta_kill_monster(monster, monster.position.tile, *MyPlayer);
-		NetSendCmdLocParam1(false, CMD_MONSTDEATH, monster.position.tile, monster.getId());
+		NetSendCmdLocParam1(false, CMD_MONSTDEATH, monster.position.tile, static_cast<uint16_t>(monster.getId()));
 		return;
 	}
 
 	delta_monster_hp(monster, *MyPlayer);
-	NetSendCmdMonDmg(false, monster.getId(), damage);
+	NetSendCmdMonDmg(false, static_cast<uint16_t>(monster.getId()), damage);
 }
 
 bool M_Talker(const Monster &monster)
@@ -3727,7 +3727,7 @@ void M_StartHit(Monster &monster, const Player &player, int dam)
 {
 	monster.tag(player);
 	if (IsHardHit(monster, dam)) {
-		monster.enemy = player.getId();
+		monster.enemy = static_cast<uint8_t>(player.getId());
 		monster.enemyPosition = player.position.future;
 		monster.flags &= ~MFLAG_TARGETS_MONSTER;
 		if (monster.mode != MonsterMode::Petrified) {
@@ -4686,7 +4686,7 @@ void Monster::setLeader(const Monster *leader)
 		return;
 	}
 
-	this->leader = leader->getId();
+	this->leader = static_cast<uint8_t>(leader->getId());
 	leaderRelation = LeaderRelation::Leashed;
 	ai = leader->ai;
 }