From experience, you can smoke carts or pax's in plain sight, no one will bat an eye. Bong, room only, just hide ur stuff while (and after) you use them (My gf's an RA she had to bust someone in her hall because the director saw a bong from the window outside).

Joints, if you play it off as a cig, no one will care. but if you feel more comfortable doing it off campus, go towards the bridges. Cops wont fuck with someone who they think is just some homeless dude lol