2, 3, or 4 (some big rooms in Pershing), and generally you change rooms and roommates every semester within your assigned company (which you have no control over). Plebes usually have no option of picking their roommates. Upperclasses often can keep specific roommates, though they will often still move rooms. Depending on the mood of specific commandants, you will possibly switch companies after your plebe or yuk year called scrambling. Between semester room clearing, scrambling, barracks renovation, and staff time, you can expect to have to live in 8 different rooms, with different roommates regularly, and have to haul all your stuff by hand down to the trunk room each time or worse, from like Lee barracks all the way to Mac short after scrambling companies.