There are several swap shelves spread across the campus where you can help yourself. The principle is very simple: if you like a game or book on the swap shelf, simply take it with you and replace it with something similar that you still have at home but no longer need. This way you can always get new reading and playing material without having to pay money for it. You will find the CampusPlus exchange shelf by the underpass between buildings 46 & 48. There are other exchange shelves at the AStA (Building 464 - 205) and in the Social Sciences Department (Building 57 - 4th floor). The shelves become more exciting every week as you fill them with new life. Have fun with it!