diff --git a/a3/world.h b/a3/world.h
index e69de29..c5aca99 100644
--- a/a3/world.h
+++ b/a3/world.h
@@ -0,0 +1,14 @@
+#ifndef WORLD_H_INCLUDED
+#define WORLD_H_INCLUDED
+
+#include "snake.h"
+
+//Initialize a new game state.
+struct state* create_world(int width, int height);
+
+void free_world(struct state* st);
+
+// Change snake direction
+void change_direction(struct state* st, int dx, int dy);
+
+#endif // WORLD_H_INCLUDED