diff --git a/Source/debug.cpp b/Source/debug.cpp
index 0fa128a93..7e7c0859e 100644
--- a/Source/debug.cpp
+++ b/Source/debug.cpp
@@ -15,7 +15,6 @@
 namespace devilution {
 
 #ifdef _DEBUG
-bool update_seed_check = false;
 
 #define DEBUGSEEDS 4096
 int seed_index;
@@ -39,10 +38,8 @@ void FreeDebugGFX()
 
 void CheckDungeonClear()
 {
-	int i, j;
-
-	for (j = 0; j < MAXDUNY; j++) {
-		for (i = 0; i < MAXDUNX; i++) {
+	for (int j = 0; j < MAXDUNY; j++) {
+		for (int i = 0; i < MAXDUNX; i++) {
 			if (dMonster[i][j] != 0)
 				app_fatal("Monsters not cleared");
 			if (dPlayer[i][j] != 0)
@@ -58,16 +55,17 @@ void GiveGoldCheat()
 {
 	auto &myPlayer = plr[myplr];
 
-	for (int i = 0; i < NUM_INV_GRID_ELEM; i++) {
-		if (myPlayer.InvGrid[i] == 0) {
-			int ni = myPlayer._pNumInv++;
-			SetPlrHandItem(&myPlayer.InvList[ni], IDI_GOLD);
-			GetPlrHandSeed(&myPlayer.InvList[ni]);
-			myPlayer.InvList[ni]._ivalue = GOLD_MAX_LIMIT;
-			myPlayer.InvList[ni]._iCurs = ICURS_GOLD_LARGE;
-			myPlayer._pGold += GOLD_MAX_LIMIT;
-			myPlayer.InvGrid[i] = myPlayer._pNumInv;
-		}
+	for (int8_t &itemId : myPlayer.InvGrid) {
+		if (itemId != 0)
+			continue;
+
+		int ni = myPlayer._pNumInv++;
+		SetPlrHandItem(&myPlayer.InvList[ni], IDI_GOLD);
+		GetPlrHandSeed(&myPlayer.InvList[ni]);
+		myPlayer.InvList[ni]._ivalue = GOLD_MAX_LIMIT;
+		myPlayer.InvList[ni]._iCurs = ICURS_GOLD_LARGE;
+		myPlayer._pGold += GOLD_MAX_LIMIT;
+		itemId = myPlayer._pNumInv;
 	}
 }
 
@@ -75,15 +73,15 @@ void TakeGoldCheat()
 {
 	auto &myPlayer = plr[myplr];
 
-	for (int i = 0; i < NUM_INV_GRID_ELEM; i++) {
-		int8_t ig = myPlayer.InvGrid[i];
-		if (ig > 0 && myPlayer.InvList[ig - 1]._itype == ITYPE_GOLD)
-			myPlayer.RemoveInvItem(ig - 1);
-	}
+	for (auto itemId : myPlayer.InvGrid) {
+		itemId -= 1;
 
-	for (int i = 0; i < MAXBELTITEMS; i++) {
-		if (myPlayer.SpdList[i]._itype == ITYPE_GOLD)
-			myPlayer.SpdList[i]._itype = ITYPE_NONE;
+		if (itemId < 0)
+			continue;
+		if (myPlayer.InvList[itemId]._itype != ITYPE_GOLD)
+			continue;
+
+		myPlayer.RemoveInvItem(itemId);
 	}
 
 	myPlayer._pGold = 0;
@@ -146,20 +144,20 @@ void PrintDebugPlayer(bool bNextPlayer)
 
 	auto &player = plr[dbgplr];
 
-	sprintf(dstr, "Plr %i : Active = %i", dbgplr, player.plractive);
+	sprintf(dstr, "Plr %i : Active = %i", dbgplr, player.plractive ? 1 : 0);
 	NetSendCmdString(1 << myplr, dstr);
 
 	if (player.plractive) {
 		sprintf(dstr, "  Plr %i is %s", dbgplr, player._pName);
 		NetSendCmdString(1 << myplr, dstr);
-		sprintf(dstr, "  Lvl = %i : Change = %i", player.plrlevel, player._pLvlChanging);
+		sprintf(dstr, "  Lvl = %i : Change = %i", player.plrlevel, player._pLvlChanging ? 1 : 0);
 		NetSendCmdString(1 << myplr, dstr);
 		const Point target = player.GetTargetPosition();
 		sprintf(dstr, "  x = %i, y = %i : tx = %i, ty = %i", player.position.tile.x, player.position.tile.y, target.x, target.y);
 		NetSendCmdString(1 << myplr, dstr);
 		sprintf(dstr, "  mode = %i : daction = %i : walk[0] = %i", player._pmode, player.destAction, player.walkpath[0]);
 		NetSendCmdString(1 << myplr, dstr);
-		sprintf(dstr, "  inv = %i : hp = %i", player._pInvincible, player._pHitPoints);
+		sprintf(dstr, "  inv = %i : hp = %i", player._pInvincible ? 1 : 0, player._pHitPoints);
 		NetSendCmdString(1 << myplr, dstr);
 	}
 }
@@ -200,7 +198,7 @@ void PrintDebugMonster(int m)
 			bActive = true;
 	}
 
-	sprintf(dstr, "Active List = %i, Squelch = %i", bActive, monster[m]._msquelch);
+	sprintf(dstr, "Active List = %i, Squelch = %i", bActive ? 1 : 0, monster[m]._msquelch);
 	NetSendCmdString(1 << myplr, dstr);
 }
 
@@ -208,11 +206,9 @@ int dbgmon;
 
 void GetDebugMonster()
 {
-	int mi1, mi2;
-
-	mi1 = pcursmonst;
+	int mi1 = pcursmonst;
 	if (mi1 == -1) {
-		mi2 = dMonster[cursmx][cursmy];
+		int mi2 = dMonster[cursmx][cursmy];
 		if (mi2 != 0) {
 			mi1 = mi2 - 1;
 			if (mi2 <= 0)
@@ -235,6 +231,7 @@ void NextDebugMonster()
 	sprintf(dstr, "Current debug monster = %i", dbgmon);
 	NetSendCmdString(1 << myplr, dstr);
 }
+
 #endif
 
 } // namespace devilution
diff --git a/Source/diablo.cpp b/Source/diablo.cpp
index 8ea2b49ba..10a5558e7 100644
--- a/Source/diablo.cpp
+++ b/Source/diablo.cpp
@@ -1198,7 +1198,7 @@ static void PressChar(int32_t vkey)
 
 static void GetMousePos(int32_t lParam)
 {
-	MousePosition = { (short)(lParam & 0xffff), (short)((lParam >> 16) & 0xffff) };
+	MousePosition = { (std::int16_t)(lParam & 0xffff), (std::int16_t)((lParam >> 16) & 0xffff) };
 }
 
 void DisableInputWndProc(uint32_t uMsg, int32_t /*wParam*/, int32_t lParam)
diff --git a/Source/doom.cpp b/Source/doom.cpp
index 686c28d27..0f94f3e9f 100644
--- a/Source/doom.cpp
+++ b/Source/doom.cpp
@@ -21,24 +21,6 @@ int DoomQuestTime;
 bool DoomFlag;
 int DoomQuestState;
 
-/*
-void doom_reset_state()
-{
-	DoomQuestState = std::max(DoomQuestState, 0);
-}
-
-void doom_play_movie()
-{
-	if (DoomQuestState >= 36001)
-		return;
-        DoomQuestState++;
-	if (DoomQuestState == 36001) {
-		PlayInGameMovie("gendata\\doom.smk");
-		DoomQuestState++;
-	}
-}
-*/
-
 int doom_get_frame_from_time()
 {
 	if (DoomQuestState == 36001) {
diff --git a/Source/lighting.cpp b/Source/lighting.cpp
index 7feadd616..0e5f90aef 100644
--- a/Source/lighting.cpp
+++ b/Source/lighting.cpp
@@ -667,7 +667,7 @@ void DoVision(Point position, int nRadius, bool doautomap, bool visible)
 	int nCrawlX, nCrawlY, nLineLen, nTrans;
 	int j, k, v, x1adj, x2adj, y1adj, y2adj;
 
-	if (position.x >= 0 && position.x<= MAXDUNX && position.y >= 0 && position.y <= MAXDUNY) {
+	if (position.x >= 0 && position.x <= MAXDUNX && position.y >= 0 && position.y <= MAXDUNY) {
 		if (doautomap) {
 			if (dFlags[position.x][position.y] != 0) {
 				SetAutomapView(position);
@@ -941,7 +941,7 @@ void MakeLightTable()
 #ifdef _DEBUG
 void ToggleLighting()
 {
-	lightflag ^= true;
+	lightflag = !lightflag;
 
 	if (lightflag) {
 		memset(dLight, 0, sizeof(dLight));
diff --git a/Source/player.cpp b/Source/player.cpp
index 2ef7fb54a..43186616c 100644
--- a/Source/player.cpp
+++ b/Source/player.cpp
@@ -1260,7 +1260,7 @@ void InitPlayer(int pnum, bool FirstTime)
 #ifdef _DEBUG
 	if (debug_mode_dollar_sign && FirstTime) {
 		player._pMemSpells |= 1 << (SPL_TELEPORT - 1);
-		if (!myPlayer._pSplLvl[SPL_TELEPORT]) {
+		if (myPlayer._pSplLvl[SPL_TELEPORT] == 0) {
 			myPlayer._pSplLvl[SPL_TELEPORT] = 1;
 		}
 	}
diff --git a/Source/scrollrt.cpp b/Source/scrollrt.cpp
index e20a14d32..c71422f7d 100644
--- a/Source/scrollrt.cpp
+++ b/Source/scrollrt.cpp
@@ -767,7 +767,7 @@ static void scrollrt_draw_dungeon(const CelOutputBuffer &out, int sx, int sy, in
 		negMon = dMonster[sx][sy - 1];
 
 #ifdef _DEBUG
-	if (visiondebug && bFlag & BFLAG_LIT) {
+	if (visiondebug && (bFlag & BFLAG_LIT) != 0) {
 		CelClippedDrawTo(out, { dx, dy }, *pSquareCel, 1);
 	}
 #endif
diff --git a/Source/trigs.cpp b/Source/trigs.cpp
index 290ec4bb4..8c2a3b9fd 100644
--- a/Source/trigs.cpp
+++ b/Source/trigs.cpp
@@ -84,7 +84,7 @@ void InitTownTriggers()
 			trigs[numtrigs]._tmsg = WM_DIABTOWNWARP;
 			trigs[numtrigs]._tlvl = 5;
 #ifdef _DEBUG
-			if (debug_mode_key_j)
+			if (debug_mode_key_j != 0)
 				trigs[numtrigs]._tlvl = debug_mode_key_j;
 #endif
 			numtrigs++;