1. The "Woo!" girl:
2. The girl in the bathroom who thinks you're sooo pretty:
3. Some guy named Chad:
4. The birthday girl:
5. The guy with a tab:
6. The guy who fucking loves college:
7. The honorary bro:

You've definitely met them all before.
She's loud, she's proud, and she's on her eighth tequila shot.
Drunk girls in bathrooms are the nicest people you'll never see again. But you'll always have that low-quality Snapchat selfie.
You know the guy I'm talking about.
If you couldn't tell by her sash and tiara, don't worry — she'll be screaming it all night while downing free drinks.
This guy will start a tab just to impress a girl or show off to his friends. Spending $312 on drinks won't be the only thing he regrets the next morning.
If this guy's life had a soundtrack, it would be Asher Roth's "I Love College," no doubt about it.
This girl is squad deep with her guy friends and drinks only beer.
They'll ask everyone in the bar to look for their phone until they eventually find it in their back pocket.
This person cannot speak coherently or walk without assistance. Eventually their slightly-less-drunk friend will get them in a cab while they scream, "Seroslllyy I'm tooottlly fynnne."
This kid has the in, which means no waiting in line and no paying cover. Probably named Chad (see #3).
They're cooler than you and will make sure you know it. They're actually 21 and don't have to worry about memorizing a fake birthday and zip code. They know exactly what to order, and they drink to forget they're graduating in a matter of months.
She has tissues, snacks, and Band-Aids, and she's everyone's emergency contact. She'll spend the night wishing she could use child leashes to keep her drunk friends from wandering off.
They look the same, talk the same, and order the same drink. They got dressed together, came together, and will be attached at the hip all night — until they leave to get pizza together.