diff --git a/Aquaria/Game.h b/Aquaria/Game.h
index 455429a..2320345 100644
--- a/Aquaria/Game.h
+++ b/Aquaria/Game.h
@@ -572,6 +572,7 @@ typedef std::vector<QuadList> QuadArray;
 typedef std::vector<Element*> ElementUpdateList;
 
 // Note: although this is a bitmask, only one of these values may be set at a time!
+// This is because GridRender and most Lua scripts check via ==, not for bits set (Lua 5.1 doesn't have bit ops)
 enum ObsType
 {
 	OT_EMPTY		= 0x00,
@@ -596,6 +597,8 @@ enum ObsType
 	OT_USER1 = 0x40,
 	OT_USER2 = 0x80,
 	OT_USER_MASK = OT_USER1 | OT_USER2,
+
+	OT_OUTOFBOUNDS = 0xff
 };
 
 struct EntitySaveData
@@ -635,6 +638,7 @@ public:
 	void setGrid(const TileVector &tile, ObsType v);
 	void addGrid(const TileVector &tile, ObsType v);
 	bool isObstructed(const TileVector &tile, int t = OT_BLOCKING) const;
+	bool isObstructedRaw(const TileVector &tile, int t) const;
 	void trimGrid();
 	void dilateGrid(unsigned int radius, ObsType test, ObsType set, ObsType allowOverwrite);
 
@@ -1213,7 +1217,7 @@ ObsType Game::getGridRaw(const TileVector &tile) const
 {
 	return (unsigned(tile.x) < unsigned(MAX_GRID) && unsigned(tile.y) < unsigned(MAX_GRID))
 		? ObsType(grid[tile.x][tile.y])
-		: OT_INVISIBLE;
+		: OT_OUTOFBOUNDS;
 }
 
 inline
@@ -1255,4 +1259,10 @@ bool Game::isObstructed(const TileVector &tile, int t /* = OT_BLOCKING */) const
 	return (getGrid(tile) & t);
 }
 
+inline
+bool Game::isObstructedRaw(const TileVector &tile, int t) const
+{
+	return (getGridRaw(tile) & t);
+}
+
 #endif
diff --git a/Aquaria/ScriptInterface.cpp b/Aquaria/ScriptInterface.cpp
index 12ea729..16fdfae 100644
--- a/Aquaria/ScriptInterface.cpp
+++ b/Aquaria/ScriptInterface.cpp
@@ -898,6 +898,17 @@ luaFunc(getModPath)
 	luaReturnStr(path.c_str());
 }
 
+luaFunc(getInterfaceFunctionNames)
+{
+	lua_newtable(L);
+	for(unsigned i = 0; interfaceFunctions[i]; ++i)
+	{
+		lua_pushstring(L, interfaceFunctions[i]);
+		lua_rawseti(L, -2, i+1);
+	}
+	return 1;
+}
+
 
 
 // ----- RenderObject common functions -----
@@ -8681,6 +8692,12 @@ luaFunc(isObstructed)
 	luaReturnBool(dsq->game->isObstructed(TileVector(Vector(lua_tonumber(L, 1), lua_tonumber(L, 2))), obs ? obs : -1));
 }
 
+luaFunc(isObstructedRaw)
+{
+	int obs = lua_tointeger(L, 3);
+	luaReturnBool(dsq->game->isObstructedRaw(TileVector(Vector(lua_tonumber(L, 1), lua_tonumber(L, 2))), obs));
+}
+
 luaFunc(getObstruction)
 {
 	luaReturnInt(dsq->game->getGrid(TileVector(Vector(lua_tonumber(L, 1), lua_tonumber(L, 2)))));
@@ -9402,6 +9419,7 @@ static const struct {
 	luaRegister(fileExists),
 	luaRegister(getModName),
 	luaRegister(getModPath),
+	luaRegister(getInterfaceFunctionNames),
 
 	luaRegister(debugBreak),
 	luaRegister(setIgnoreAction),
@@ -9952,6 +9970,7 @@ static const struct {
 
 	luaRegister(singSong),
 	luaRegister(isObstructed),
+	luaRegister(isObstructedRaw),
 	luaRegister(isObstructedBlock),
 	luaRegister(getObstruction),
 	luaRegister(getGridRaw),
@@ -11124,6 +11143,7 @@ static const struct {
 	luaConstant(OT_MASK_BLACK),
 	luaConstant(OT_BLOCKING),
 	luaConstant(OT_USER_MASK),
+	luaConstant(OT_OUTOFBOUNDS),
 
 	luaConstant(SEE_MAP_NEVER),
 	luaConstant(SEE_MAP_DEFAULT),