The greek system dominates the social scene, to the detriment of those who do not join it. I spent freshman year going to frat parties, like most everyone, but wanted nothing to do with the greek system when it came time to rush. Bars close at 1 AM (or did while I was in school) and were also dominated by the greek system. House parties in collegetown are house parties; they're as cool as the people who show up. If you have cool friends you'll have cool house parties to go to. Each year on the last day of classes is slope day, when all the students skip class to sit on the big slope on campus, drink, smoke, and hang out. Although by the time I graduated they had neutered it into a quasi-high school dance with ID and bag checks, fences, guards, and entrances. Not like the good old days, but still fun. Also, Dragon Day is an annual tradition where the architecture students build a giant dragon, parade it around campus, and then burn it. Why? "Why" is not a question that architects bother with very much outside the classroom. Also, the engineers would build a phoenix and attempt to rival the dragon on the parade, or destroy the dragon before the parade finished. Also, no reason given. A number of violent incidents (engineers versus architechts -- glasses everywhere!)led the administration to also bring this one under control by involving Ithaca's finest in the parade plans. Despite sounding really, really stupid, the architechture school is one of the best in the world so the dragon is usually flat out sick.
I'll do a survey of drugs on campus since I doubt anyone else will. First, alcohol: the cause of, and solution to, all of life's problems. While I was there, the administration started passing out "zero-to-three" paraphenalia, zero-to-three being the average number of drinks consumed by a Cornell student while drinking, according to surveys. The program included really cool free mini frisbees, which my friends and I used for a long time. Of course, statistics can be tricky things (if each year, you make $1,000,000 and your roommate makes $0, you have an average household income of $500,000). Drinking pretty much breaks down the way you'd expect: nerds don't stop studying to drink, greek system kids don't stop drinking ever, and everyone else falls somewhere in between. Choose your friends to suit however much drinking you like to do, and you'll be fine. Unless you end up in one of these Darwin awards stories like the idiot my freshman year who got so drunk he fell out of a third floor window and broke his leg. AND, the window only opened from the bottom so you couldn't fall out of it! Dunce.
One thing you will learn at Cornell, as I did, that there are different kinds of smart, and even if someone is good at math, they still might be a complete ass outside the classroom.
Next: weed. Naturally, the climate is authentically cold (in February, anything over 20 degrees is a nice day), and some nights there's just not a good enough reason to venture out, and sitting around an apartment watching DVD's leads inevitably to marijuana. Which leads inevitably to DP Dough (if you don't know, ask somebody). As with booze, suit the friends you make to the amount of this you want to do.
Now we get into the real fancy stuff: cocaine and ecstacy. Cocaine is not my thing, but I had friends who used it occasionally. The wealthier frats had plenty of it around although it was usually a hushed up operation, either because they didn't want to get caught or because they didn't want to share; probably both. Ecstacy was around, of course, but you had to hunt for it; generally a good place to start was down at Theta-Delta (aka Theta-Delt, aka Theta-Drug), but that's five year old intelligence, so who knows? Maybe that house is all country clubbers now.
Halucinagenics -- LSD and Mushrooms -- were around, too, if you moved in the right circles. There was a campus hip-hop group I really liked and I remember seeing one of their shows when a friend told me that the DJ was tripping acid for the first time; he was performing pretty well, all things considered. I also remember there was one really bright student who was into mushrooms and once parked her car in the middle of campus and ran two miles back to her house in collegetown, naked. Later that year, she was tripping mushrooms and fell over a railing, plunging five floors to her instant death. The Hotel school is only a couple hundred kids, and everyone knew her; the loss was very traumatic.
Drugs are dangerous. But, so is getting out of bed. All of this is about who you make friends with. No one is going to foist drugs on you and if you don't want it you really can do like Nancy Regan says and Just Say No. Make your own decisions.