That fridge There’s a fridge in the office that needs to be cleaned out once a week. Nobody does, though, and you hate it. You do not hate it enough to clean it every week yourself. But you would gladly clean it out once in a while, if only your colleagues took turns with you. Anyway, you decide to give it a shot. One random Friday you clean it out well, in the hope that your efforts will be appreciated and returned in kind. What sort of game are you playing with your colleagues?