Like napolitana said, all schools are different and roommates can be a gamble. My university can go into your room and search your shit whenever they want, but never did. Occasionally they will have a fire safety check (so don't leave anything out). I was fine leaving my stuff in my drawer and my roommate had his bubbler between his TV and his wall, without any problems. I don't recommend a bong or blunt or anything that makes a lot of smoke, and set up a fan by the window and blow through a cardboard tube with a dryer sheet over one end (to kill the weed smell). All this is if you don't have a smoke detector in your room. I only had a sprinkler, so i was good but next year I'll have a detector so I got a vaporizer. I lived above and next to R.A.'s and never got caught (almost did once cuz the R.A. below me had her window open and smelled it).

P.S. I became really good friends with my roommate (he doesn't smoke). It's the luck of the draw. You can probably switch rooms after the first semester if your roommate really sucks.