The rule that states that if you don't like what you see from a person in the first ten seconds you see them, than you will most likely not like them later on.
Is ussually used on apparent douchebags, seemingly annoying bitches, or preppy-ass motherfuckers.
Jim: Ay, Carl! Look at that guy over there.
(Carl looks at apparent douchebage and applies 10-Second Rule)
Carl: He looks like a fucking douche.