A roommate contract is an agreement whereby the residents of a room agree to certain conditions. These conditions may not be rules of the hall, but become rules of the room.
For example, if one roommate has an 8:00 class every morning, it might be stipulated in the contract, that no guests are permitted after 10:00 pm. Or, if one roommate likes to study in the room, it might be a rule that the stereo cannot be on after 8:00 pm.
If you and your roommate are basically getting along, but having trouble in certain areas, a roommate contract may be just what you need! See your RA for details!