diff --git a/src/behaviour_entity.h b/src/behaviour_entity.h
new file mode 100644
index 0000000..c0d22ee
--- /dev/null
+++ b/src/behaviour_entity.h
@@ -0,0 +1,30 @@
+#ifndef _update_entity_h
+#define _update_entity_h
+
+#include "typeclass_helpers.h"
+#include "vmath.h"
+
+typedef struct {
+    void (*const spawn)(void* self, Vector at);
+    void (*const update)(void* self, float dt);
+    void (*const start)(void* self);
+} IEntityBehaviour;
+
+typedef struct {
+    void* data;
+    IEntityBehaviour const* tc;
+} BehaviourEntity;
+
+#define impl_BehaviourEntity_for(T, start_f, update_f, spawn_f)\
+static inline BehaviourEntity T##_as_BehaviourEntity(T* x) {\
+    TC_FN_TYPECHECK(void, start_f, T*);\
+    TC_FN_TYPECHECK(void, update_f, T*, float);\
+    static IEntityBehaviour const tc = {\
+        .spawn =   (void(*const)(void*, Vector)) spawn_f,\
+        .update =  (void(*const)(void*, float))  update_f,\
+        .start =   (void(*const)(void*))         start_f\
+    };\
+    return (BehaviourEntity){.tc = &tc, .data = x};\
+}\
+
+#endif // !_update_entity_h
diff --git a/src/player.c b/src/player.c
index ba359e2..659c5ba 100644
--- a/src/player.c
+++ b/src/player.c
@@ -8,6 +8,10 @@ void player_start(Player* self) {
     self->transform = IdentityTransform;
 }
 
+void player_update(Player* self, float dt) {
+    
+}
+
 Transform* player_get_transform(Player* self) {
     return &self->transform;
 }
diff --git a/src/player.h b/src/player.h
index eb1715c..c7a3034 100644
--- a/src/player.h
+++ b/src/player.h
@@ -2,7 +2,7 @@
 #define _fencer_player_h
 
 #include "physics_entity.h"
-#include "update_entity.h"
+#include "behaviour_entity.h"
 #include "transformable.h"
 #include "sprite.h"
 
@@ -18,6 +18,8 @@ extern void player_spawn(Player* self, Vector at);
 extern void player_start(Player* self);
 extern void player_update(Player* self, float dt);
 
+extern void player_collision(Player* self, Collision hit);
+
 extern Transform* player_get_transform(Player* self);
 extern RigidBody* player_get_rigidbody(Player* self);
 extern Shape* player_get_shape(Player* self);
@@ -32,10 +34,13 @@ impl_Transformable_for(Player,
     player_get_scale,
     player_get_rotation
 )
+
 impl_PhysicsEntity_for(Player,
     player_get_rigidbody,
-    player_get_shape
+    player_get_shape,
+    player_collision
 )
+
 impl_BehaviourEntity_for(Player,
     player_start,
     player_update,