This expansion adds 12 new tiles for you to print out and add to the game. 6 tiles feature barriers, which are similar to the Abbey tiles from the Abbey & Mayor expansion. These barriers may be played against any tile feature (city, field or road). The other 6 tiles include city walls which can only be placed against cities. The city walls help to close off cities, but when you're scoring the city, you may not include the tile that only has a city wall on it.