An often unexamined strategic interaction occurs daily on college campuses across the world: choices among roommates regarding who will clean the room. This situation is modeled in the game below with two roommates: Gaius and Alberto. Every day, each has a choice to clean the room or not to clean it. Both are happier with a clean room, but each is happiest when the other cleans and he doesn't. Each is least happy when he cleans and the other does not. The payoffs below can be interpreted as the utility each player receives. For example, if Alberto chooses not to clean and Gaius chooses to clean, Alberto receives 90 utility and Gaius receives 30 utility. Roommate Game Gaius Clean Don't clean Alberto Clean 75, 75 30, 90 Don't clean 90, 30 45, 45