diff --git a/mario/objectids.hpp b/mario/objectids.hpp
index 3b5ef73..7d63300 100644
--- a/mario/objectids.hpp
+++ b/mario/objectids.hpp
@@ -65,13 +65,14 @@
 #define MUSHROOM_ID 0x703C
 
 // modifiers
-#define DESTRUCTIBLE_MODIFIER_ID 0x01
-#define BACKGROUND_MODIFIER_ID 0x02
-#define COIN_MODIFIER_ID 0x03
-#define MUSHROOM_MODIFIER_ID 0x04
+#define DESTRUCTIBLE_MODIFIER_ID 0x6001
+#define BACKGROUND_MODIFIER_ID 0x6002
+#define COIN_MODIFIER_ID 0x6003
+#define MUSHROOM_MODIFIER_ID 0x6004
 
 // character IDs
 #define MARIO_ID 0x0F
+#define GOOMBA_ID 0x0E
 
 #define DEATH_ID 0x1001
 #define STOP_MOVEMENT 0x2000
@@ -82,6 +83,12 @@
 #define MARIO_TOP_DETECT 0x2004
 #define MARIO_TOP_LEFT_DETECT 0x2005
 #define MARIO_TOP_RIGHT_DETECT 0x2006
+#define MARIO_ENEMY_DETECT 0x2007
+
+#define NPC_FLOOR_DETECT 0x2008
+#define NPC_LEFT_SIDE_DETECT 0x2009
+#define NPC_RIGHT_SIDE_DETECT 0x200A
+#define NPC_TOP_DETECT 0x200B
 
 #define EDITOR_EDIT_SQUARE 0xF001
 #define EDITOR_MOUSE_ID 0xF002