--- a/skaapsteker/sprites/base.py	Sat Apr 09 14:22:04 2011 +0200
+++ b/skaapsteker/sprites/base.py	Sat Apr 09 14:25:45 2011 +0200
@@ -19,7 +19,7 @@
 PC_LAYER = 0
 MONSTER_LAYER = 1
 NPC_LAYER = 2
-
+PROJECTILE_LAYER = 3
 
 
 class GameSprite(Sprite):
@@ -141,7 +141,7 @@
 class Monster(AnimatedGameSprite):
 
     collision_layer = MONSTER_LAYER
-    collides_with = set([PC_LAYER])
+    collides_with = set([PC_LAYER, PROJECTILE_LAYER])
 
     debug_color = (240, 120, 120)
 
@@ -207,6 +207,7 @@
 class NPC(AnimatedGameSprite):
 
     collision_layer = NPC_LAYER
+    collides_with = set([])
 
     debug_color = (240, 240, 240)
     bounce_factor = (0, 0)    #  NPC's don't bounce by default
@@ -227,8 +228,30 @@
 
 
 class Projectile(AnimatedGameSprite):
+
+    collision_layer = PROJECTILE_LAYER
+    collides_with = set()
+
     gravitates = False
 
+    DAMAGE = 10
+
+    def setup(self, hits):
+        if isinstance(hits, tuple):
+            self.hits = hits + (Geography,)
+        else:
+            self.hits = (hits, Geography)
+
+    def explode(self):
+        self.kill()
+
+    def collided(self, other):
+        if not isinstance(other, self.hits):
+            return
+        if hasattr(other, 'damage'):
+            other.damage(self.DAMAGE)
+        self.explode()
+
 
 class Item(GameSprite):
     mobile = False
@@ -263,7 +286,7 @@
 class Geography(Sprite):
     mobile = False
     gravitates = False
-    collides_with = set([PC_LAYER, MONSTER_LAYER, NPC_LAYER])
+    collides_with = set([PC_LAYER, MONSTER_LAYER, NPC_LAYER, PROJECTILE_LAYER])
     is_ground = True
     actionable = False
     bounce_factor = (0.0, 0.0)