Well, from my dorm life back in the day (1988-93 Louisiana Tech):
Cash, and not cash that was drinking money, not cash that anyone knew about
Ramen, canned soup, crackers, etc see above
Doorstop to bar entry or chair, something to bar entry
Tools, need basic handtools to change girls' car batteries, etc
Tarp or sheet plastic to cover car window that some drunk sumbitch broke in dorm parking lot
FixAFlat, jumper cables, HEET, duct tape, etc for vehicle
Off campus BOL, friend of family, church member, someone
Copies (could use USB drive nowadays) of prescriptions, contact prescription, car title, registration, birth certificate, DL
Flashlight, couple jugs water
Biggest SHTF events in my 5 years undergrad: hurricane blew out over Northern LA and dumped 12" rain in 8 hours, no means to go home, car hit 4 times in 2 years, water out in dorms multiple times (jugs water for bathing in sink), drunks coming to my room because some guy USED to live there who's ass they wanted to kick,
AND FRIENDS OF FRIENDS WILL STEAL YOUR STUFF. Hide your stuff in ceiling tile, under drawers, whatever, someone WILL steal your stuff. You may trust your roommate, but do you trust him not to turn his back on a friend of a friend for seconds?
Also, the campus cops have total access to your vehicle probably, so don't count on keeping anything questionable there.
oh, yeah, and about the rainstorms/no means to get home- get a map and have 2-3 ways to get home no matter how goofy they look on paper, once had to go 30 miles East to Monroe, North 30 miles and West 30 miles.......90 miles, just to get to destination that was only 40 odd miles away as crow flies. At night, in rainstorm, after working 15 hours, etc.