diff --git a/engines/dm/champion.h b/engines/dm/champion.h
index 2428308c3ebb..4e9e29d9c74e 100644
--- a/engines/dm/champion.h
+++ b/engines/dm/champion.h
@@ -9,7 +9,7 @@ namespace DM {
 class Scent {
 	uint16 _scent;
 public:
-	Scent(uint16 scent = 0): _scent(scent) {}
+	explicit Scent(uint16 scent = 0): _scent(scent) {}
 
 	uint16 getMapX() { return _scent & 0x1F; }
 	uint16 getMapY() { return (_scent >> 5) & 0x1F; }
@@ -403,7 +403,7 @@ class ChampionMan {
 	bool _leaderEmptyHanded; // @ G0415_B_LeaderEmptyHanded
 	Party _party; // @ G0407_s_Party
 
-	ChampionMan(DMEngine *vm);
+	explicit ChampionMan(DMEngine *vm);
 	void resetDataToStartGame(); // @ F0278_CHAMPION_ResetDataToStartGame
 	void addCandidateChampionToParty(uint16 championPortraitIndex); // @ F0280_CHAMPION_AddCandidateChampionToParty
 	void drawChampionBarGraphs(ChampionIndex champIndex); // @ F0287_CHAMPION_DrawBarGraphs
diff --git a/engines/dm/dm.h b/engines/dm/dm.h
index f2d14c942290..61583a39c1e9 100644
--- a/engines/dm/dm.h
+++ b/engines/dm/dm.h
@@ -62,7 +62,7 @@ class Thing {
 	static const Thing _thingEndOfList;
 
 	Thing() : _data(0) {}
-	Thing(uint16 d) { set(d); }
+	explicit Thing(uint16 d) { set(d); }
 
 	void set(uint16 d) {
 		_data = d;
@@ -88,7 +88,7 @@ class DMEngine : public Engine {
 	void initializeGame(); // @ F0463_START_InitializeGame_CPSADEF
 	void gameloop(); // @ F0002_MAIN_GameLoop_CPSDF
 public:
-	DMEngine(OSystem *syst);
+	explicit DMEngine(OSystem *syst);
 	~DMEngine();
 
 	virtual Common::Error run(); // @ main
@@ -120,7 +120,7 @@ class DMEngine : public Engine {
 
 class Console : public GUI::Debugger {
 public:
-	Console(DMEngine *vm) {}
+	explicit Console(DMEngine *vm) {}
 	virtual ~Console(void) {}
 };
 
diff --git a/engines/dm/dungeonman.h b/engines/dm/dungeonman.h
index 7f6e9666ba79..c5c356e8885e 100644
--- a/engines/dm/dungeonman.h
+++ b/engines/dm/dungeonman.h
@@ -157,7 +157,7 @@ class Door {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Door(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Door(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 	Thing getNextThing() { return _nextThing; }
 	bool isMeleeDestructible() { return (_attributes >> 8) & 1; }
 	bool isMagicDestructible() { return (_attributes >> 7) & 1; }
@@ -178,7 +178,7 @@ class Teleporter {
 	uint16 _attributes;
 	uint16 _destMapIndex;
 public:
-	Teleporter(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]), _destMapIndex(rawDat[2]) {}
+	explicit Teleporter(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]), _destMapIndex(rawDat[2]) {}
 	Thing getNextThing() { return _nextThing; }
 	bool makesSound() { return (_attributes >> 15) & 1; }
 	TeleporterScope getScope() { return (TeleporterScope)((_attributes >> 13) & 1); }
@@ -195,7 +195,7 @@ class TextString {
 	Thing _nextThing;
 	uint16 _textDataRef;
 public:
-	TextString(uint16 *rawDat) : _nextThing(rawDat[0]), _textDataRef(rawDat[1]) {}
+	explicit TextString(uint16 *rawDat) : _nextThing(rawDat[0]), _textDataRef(rawDat[1]) {}
 
 	Thing getNextThing() { return _nextThing; }
 	uint16 getWordOffset() { return _textDataRef >> 3; }
@@ -249,7 +249,7 @@ class Sensor {
 	uint16 _attributes;
 	uint16 _action;
 public:
-	Sensor(uint16 *rawDat) : _nextThing(rawDat[0]), _datAndType(rawDat[1]), _attributes(rawDat[2]), _action(rawDat[3]) {}
+	explicit Sensor(uint16 *rawDat) : _nextThing(rawDat[0]), _datAndType(rawDat[1]), _attributes(rawDat[2]), _action(rawDat[3]) {}
 
 	Thing getNextThing() { return _nextThing; }
 	SensorType getType() { return (SensorType)(_datAndType & 0x7F); } // @ M39_TYPE
@@ -280,7 +280,7 @@ class Group {
 	uint16 _health[4];
 	uint16 _attributes;
 public:
-	Group(uint16 *rawDat) : _nextThing(rawDat[0]), _possessionID(rawDat[1]), _type(rawDat[2]),
+	explicit Group(uint16 *rawDat) : _nextThing(rawDat[0]), _possessionID(rawDat[1]), _type(rawDat[2]),
 		_position(rawDat[3]), _attributes(rawDat[8]) {
 		_health[0] = rawDat[4];
 		_health[1] = rawDat[5];
@@ -307,7 +307,7 @@ class Weapon {
 	Thing _nextThing;
 	uint16 _desc;
 public:
-	Weapon(uint16 *rawDat) : _nextThing(rawDat[0]), _desc(rawDat[1]) {}
+	explicit Weapon(uint16 *rawDat) : _nextThing(rawDat[0]), _desc(rawDat[1]) {}
 
 	WeaponType getType() { return (WeaponType)(_desc & 0x7F); }
 	bool isLit() { return (_desc >> 15) & 1; }
@@ -326,7 +326,7 @@ class Armour {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Armour(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Armour(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 
 	ArmourType getType() { return (ArmourType)(_attributes & 0x7F); }
 	Thing getNextThing() { return _nextThing; }
@@ -336,7 +336,7 @@ class Scroll {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Scroll(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Scroll(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 	void set(Thing next, uint16 attribs) {
 		_nextThing = next;
 		_attributes = attribs;
@@ -364,7 +364,7 @@ class Potion {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Potion(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Potion(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 
 	PotionType getType() { return (PotionType)((_attributes >> 8) & 0x7F); }
 	Thing getNextThing() { return _nextThing; }
@@ -375,7 +375,7 @@ class Container {
 	Thing _nextContainedThing;
 	uint16 _type;
 public:
-	Container(uint16 *rawDat) : _nextThing(rawDat[0]), _nextContainedThing(rawDat[1]), _type(rawDat[2]) {}
+	explicit Container(uint16 *rawDat) : _nextThing(rawDat[0]), _nextContainedThing(rawDat[1]), _type(rawDat[2]) {}
 
 	uint16 getType() { return (_type >> 1) & 0x3; }
 	Thing getNextContainedThing() { return _nextContainedThing; }
@@ -399,7 +399,7 @@ class Junk {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Junk(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Junk(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 
 	JunkType getType() { return (JunkType)(_attributes & 0x7F); }
 	uint16 getChargeCount() { return (_attributes >> 14) & 0x3; }
@@ -414,7 +414,7 @@ class Projectile {
 	byte _damageEnergy;
 	uint16 _timerIndex;
 public:
-	Projectile(uint16 *rawDat) : _nextThing(rawDat[0]), _object(rawDat[1]), _kineticEnergy(rawDat[2]),
+	explicit Projectile(uint16 *rawDat) : _nextThing(rawDat[0]), _object(rawDat[1]), _kineticEnergy(rawDat[2]),
 		_damageEnergy(rawDat[3]), _timerIndex(rawDat[4]) {}
 
 	Thing getNextThing() { return _nextThing; }
@@ -424,7 +424,7 @@ class Explosion {
 	Thing _nextThing;
 	uint16 _attributes;
 public:
-	Explosion(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
+	explicit Explosion(uint16 *rawDat) : _nextThing(rawDat[0]), _attributes(rawDat[1]) {}
 
 	Thing getNextThing() { return _nextThing; }
 }; // @ EXPLOSION
@@ -470,8 +470,8 @@ enum SquareType {
 class Square {
 	byte _data;
 public:
-	Square(byte dat = 0) : _data(dat) {}
-	Square(SquareType type) { setType(type); }
+	explicit Square(byte dat = 0) : _data(dat) {}
+	explicit Square(SquareType type) { setType(type); }
 	Square &set(byte dat) { this->_data = dat; return *this; }
 	Square &set(SquareMask mask) { _data |= mask; return *this; }
 	byte get(SquareMask mask) { return _data & mask; }
@@ -573,7 +573,7 @@ class DungeonMan {
 	void setCurrentMap(uint16 mapIndex); // @ F0173_DUNGEON_SetCurrentMap
 
 public:
-	DungeonMan(DMEngine *dmEngine);
+	explicit DungeonMan(DMEngine *dmEngine);
 	~DungeonMan();
 
 	Thing getSquareFirstThing(int16 mapX, int16 mapY); // @ F0161_DUNGEON_GetSquareFirstThing
diff --git a/engines/dm/eventman.h b/engines/dm/eventman.h
index f72a985c5805..4b62677474a7 100644
--- a/engines/dm/eventman.h
+++ b/engines/dm/eventman.h
@@ -197,13 +197,15 @@ class EventManager {
 	void commandTurnParty(CommandType cmdType); // @ F0365_COMMAND_ProcessTypes1To2_TurnParty
 	void commandMoveParty(CommandType cmdType); // @ F0366_COMMAND_ProcessTypes3To6_MoveParty
 public:
+	explicit EventManager(DMEngine *vm);
+
 	MouseInput* _primaryMouseInput;// @ G0441_ps_PrimaryMouseInput
 	MouseInput* _secondaryMouseInput;// @ G0442_ps_SecondaryMouseInput
 	bool _mousePointerBitmapUpdated; // @ G0598_B_MousePointerBitmapUpdated
 	bool _refreshMousePointerInMainLoop; // @ G0326_B_RefreshMousePointerInMainLoop
 	bool _highlightBoxEnabled; // @ G0341_B_HighlightBoxEnabled
 	uint16 _useChampionIconOrdinalAsMousePointerBitmap; // @ G0599_ui_UseChampionIconOrdinalAsMousePointerBitmap
-	EventManager(DMEngine *vm);
+
 	void initMouse();
 	void showMouse(bool visibility);
 
diff --git a/engines/dm/gfx.h b/engines/dm/gfx.h
index 38d6630a9664..e2f30f339c52 100644
--- a/engines/dm/gfx.h
+++ b/engines/dm/gfx.h
@@ -279,7 +279,7 @@ class DisplayMan {
 	// some methods use this for a stratchpad, don't make assumptions about content between function calls
 	byte *_tmpBitmap;
 
-	DisplayMan(DMEngine *dmEngine);
+	explicit DisplayMan(DMEngine *dmEngine);
 	~DisplayMan();
 
 	void loadWallSet(WallSet set); // @ F0095_DUNGEONVIEW_LoadWallSet
diff --git a/engines/dm/inventory.h b/engines/dm/inventory.h
index aa75dc0d6dbb..b8fbe516a513 100644
--- a/engines/dm/inventory.h
+++ b/engines/dm/inventory.h
@@ -21,9 +21,11 @@ enum PanelContent {
 class InventoryMan {
 	DMEngine *_vm;
 public:
+	explicit InventoryMan(DMEngine *vm);
+
 	int16 _inventoryChampionOrdinal; // @ G0423_i_InventoryChampionOrdinal
 	PanelContent _panelContent; // @ G0424_i_PanelContent 
-	InventoryMan(DMEngine *vm);
+
 	void toggleInventory(ChampionIndex championIndex); // @ F0355_INVENTORY_Toggle_CPSE
 	void drawStatusBoxPortrait(ChampionIndex championIndex); // @ F0354_INVENTORY_DrawStatusBoxPortrait
 	void drawPanelHorizontalBar(int16 x, int16 y, int16 pixelWidth, Color color); // @ F0343_INVENTORY_DrawPanel_HorizontalBar
diff --git a/engines/dm/loadsave.h b/engines/dm/loadsave.h
index 857191200fc6..abedf549085f 100644
--- a/engines/dm/loadsave.h
+++ b/engines/dm/loadsave.h
@@ -13,13 +13,11 @@ enum LoadgameResponse {
 class LoadsaveMan {
 	DMEngine *_vm;
 public:
-	LoadsaveMan(DMEngine *vm);
+	explicit LoadsaveMan(DMEngine *vm);
 
 	LoadgameResponse loadgame(); // @ F0435_STARTEND_LoadGame_CPSF
-
 };
 
 }
 
 #endif
-
diff --git a/engines/dm/menus.h b/engines/dm/menus.h
index de0c43ac7412..edaa970bd5f9 100644
--- a/engines/dm/menus.h
+++ b/engines/dm/menus.h
@@ -9,9 +9,11 @@ namespace DM {
 class MenuMan {
 	DMEngine *_vm;
 public:
+	explicit MenuMan(DMEngine *vm);
+
 	bool _shouldRefreshActionArea; // @ G0508_B_RefreshActionArea
 	bool _actionAreaContainsIcons; // @ G0509_B_ActionAreaContainsIcons
-	MenuMan(DMEngine *vm);
+
 	void clearActingChampion(); // @ F0388_MENUS_ClearActingChampion
 	void drawActionIcon(ChampionIndex championIndex); // @ F0386_MENUS_DrawActionIcon
 
diff --git a/engines/dm/objectman.h b/engines/dm/objectman.h
index 908520c5f00b..dd0150d747bd 100644
--- a/engines/dm/objectman.h
+++ b/engines/dm/objectman.h
@@ -7,7 +7,8 @@ namespace DM {
 class ObjectMan {
 	DMEngine *_vm;
 public:
-	ObjectMan(DMEngine *vm);
+	explicit ObjectMan(DMEngine *vm);
+
 	IconIndice getObjectType(Thing thing); // @ F0032_OBJECT_GetType
 	IconIndice getIconIndex(Thing thing); // @ F0033_OBJECT_GetIconIndex
 	void extractIconFromBitmap(uint16 iconIndex, byte *srcBitmap); // F0036_OBJECT_ExtractIconFromBitmap