1% Chance

''Uh-- BOY. Look at this crit chance! (wheeze) Naaaaaaaaaahhhh, dude.''

When an event has such a ridiculously low chance of occurring that it virtually becomes impossible. This can apply to roles who Roll A 1 winning, certain UnTrashes' plays not being played, or meta events happening, such as the Innocents in old horror movies showing any form of intelligence. Obviously, this is the exact opposite of 100% Chance in terms of UnTrash, although mathematically, that'd be 0% Chance.