A common "game" where if someone stands up, they say "17's", which saves their seat for 17 minutes. Often compared to "
fives", which stole the idea from 17s, but it saves the seat for only 5 minutes. If someone steals the seat before 17 minutes are up, he is subject to beatings until he leaves the seat.
Person 1: Hey, I'm going to go buy some milk, 17's.
Person 2: (after P1 leaves, before 17 minutes) Haha I'm gonna steal his seat.
Person 3: Person 1 is gonna beat the crap out of you if you don't leave.
