diff --git a/engines/dm/detection.cpp b/engines/dm/detection.cpp
index 2d459c7d4a2..97019a987a0 100644
--- a/engines/dm/detection.cpp
+++ b/engines/dm/detection.cpp
@@ -35,7 +35,7 @@ namespace DM {
 
 static const PlainGameDescriptor DMGames[] = {
 	{"dm", "Dungeon Master"},
-	{0, 0}
+	{nullptr, nullptr}
 };
 
 static const DMADGameDescription gameDescriptions[] = {
diff --git a/engines/dm/dungeonman.cpp b/engines/dm/dungeonman.cpp
index 7f66253fc87..b62774c1c4c 100644
--- a/engines/dm/dungeonman.cpp
+++ b/engines/dm/dungeonman.cpp
@@ -1478,7 +1478,7 @@ Thing DungeonMan::getDiscardThing(uint16 thingType) {
 								} else {
 									projExpl.projectileDeleteEvent(squareThing);
 									unlinkThingFromList(squareThing, Thing(0), currMapX, currMapY);
-									projExpl.projectileDelete(squareThing, 0, currMapX, currMapY);
+									projExpl.projectileDelete(squareThing, nullptr, currMapX, currMapY);
 								}
 								break;
 							case kDMThingTypeArmour:
diff --git a/engines/dm/eventman.cpp b/engines/dm/eventman.cpp
index f87c1719dcc..f7011276d97 100644
--- a/engines/dm/eventman.cpp
+++ b/engines/dm/eventman.cpp
@@ -844,7 +844,7 @@ void EventManager::processCommandQueue() {
 			displMan.drawViewport(k2_viewportAsBeforeSleepOrFreezeGame);
 			_vm->_waitForInputMaxVerticalBlankCount = 0;
 			_primaryMouseInput = _primaryMouseInputPartySleeping;
-			_secondaryMouseInput = 0;
+			_secondaryMouseInput = nullptr;
 			_primaryKeyboardInput = _primaryKeyboardInputPartySleeping;
 			_secondaryKeyboardInput = nullptr;
 			discardAllInput();
@@ -890,7 +890,7 @@ void EventManager::processCommandQueue() {
 		primaryKeyboardInputBackup = _primaryKeyboardInput;
 		secondaryKeyboardInputBackup = _secondaryKeyboardInput;
 		_primaryMouseInput = _primaryMouseInputFrozenGame;
-		_secondaryMouseInput = 0;
+		_secondaryMouseInput = nullptr;
 		_primaryKeyboardInput = _primaryKeyboardInputFrozenGame;
 		_secondaryKeyboardInput = nullptr;
 		discardAllInput();
diff --git a/engines/dm/gfx.cpp b/engines/dm/gfx.cpp
index 813633c80c8..a82fa47b4ac 100644
--- a/engines/dm/gfx.cpp
+++ b/engines/dm/gfx.cpp
@@ -3806,7 +3806,7 @@ T0115171_BackFromT0115015_DrawProjectileAsObject:;
 					blitToBitmapShrinkWithPalChange(bitmapRedBanana, _tmpBitmap, 48, 32, 48, 32, _palChangeSmoke);
 					bitmapRedBanana = _tmpBitmap;
 				}
-				blitBoxFilledWithMaskedBitmap(bitmapRedBanana, _bitmapViewport, 0, getDerivedBitmap(kDMDerivedBitmapViewport), boxExplosionPatternD0C, _vm->getRandomNumber(4) + 87, _vm->getRandomNumber(64), k112_byteWidthViewport, Color(k0x0080_BlitDoNotUseMask | kDMColorFlesh), 0, 0, 136, 93);
+				blitBoxFilledWithMaskedBitmap(bitmapRedBanana, _bitmapViewport, nullptr, getDerivedBitmap(kDMDerivedBitmapViewport), boxExplosionPatternD0C, _vm->getRandomNumber(4) + 87, _vm->getRandomNumber(64), k112_byteWidthViewport, Color(k0x0080_BlitDoNotUseMask | kDMColorFlesh), 0, 0, 136, 93);
 				addDerivedBitmap(kDMDerivedBitmapViewport);
 				warning("DISABLED CODE: f480_releaseBlock in drawObjectsCreaturesProjectilesExplosions");
 				//f480_releaseBlock(k0_DerivedBitmapViewport | 0x8000);
@@ -3876,7 +3876,7 @@ T0115200_DrawExplosion:
 		}
 	} while ((thingParam = dungeon.getNextThing(thingParam))!= _vm->_thingEndOfList);
 
-	if ((fluxcageExplosion != 0) && (doorFrontViewDrawingPass != 1) && !_doNotDrawFluxcagesDuringEndgame) { /* Fluxcage is an explosion displayed as a field (like teleporters), above all other graphics */
+	if ((fluxcageExplosion != nullptr) && (doorFrontViewDrawingPass != 1) && !_doNotDrawFluxcagesDuringEndgame) { /* Fluxcage is an explosion displayed as a field (like teleporters), above all other graphics */
 		AL_1_viewSquareExplosionIndex -= 3; /* Convert square index for explosions back to square index */
 		FieldAspect fieldAspect = _fieldAspects188[viewSquareIndex];
 		(fieldAspect._nativeBitmapRelativeIndex)++; /* NativeBitmapRelativeIndex is now the index of the Fluxcage field graphic */
diff --git a/engines/dm/projexpl.cpp b/engines/dm/projexpl.cpp
index 3bcceb30e92..6a321b4414b 100644
--- a/engines/dm/projexpl.cpp
+++ b/engines/dm/projexpl.cpp
@@ -377,7 +377,7 @@ void ProjExpl::projectileDelete(Thing projectileThing, Thing *groupSlot, int16 m
 	Projectile *projectile = (Projectile *)_vm->_dungeonMan->getThingData(projectileThing);
 	Thing projectileSlotThing = projectile->_slot;
 	if (projectileSlotThing.getType() != kDMThingTypeExplosion) {
-		if (groupSlot != NULL) {
+		if (groupSlot != nullptr) {
 			Thing previousThing = *groupSlot;
 			if (previousThing == _vm->_thingEndOfList) {
 				Thing *genericThing = (Thing *)_vm->_dungeonMan->getThingData(projectileSlotThing);
@@ -415,7 +415,7 @@ void ProjExpl::processEvents48To49(TimelineEvent *event) {
 		uint16 stepEnergy = curEvent->_Cu._projectile.getStepEnergy();
 		if (projectile->_kineticEnergy <= stepEnergy) {
 			_vm->_dungeonMan->unlinkThingFromList(projectileThingNewCell = projectileThing, Thing(0), destinationMapX, destinationMapY);
-			projectileDelete(projectileThingNewCell, NULL, destinationMapX, destinationMapY);
+			projectileDelete(projectileThingNewCell, nullptr, destinationMapX, destinationMapY);
 			return;
 		}
 		projectile->_kineticEnergy -= stepEnergy;