Skull

Skull is simple to learn but dangerously difficult to win. Each round players place cards face down — roses and skulls — then dare each other to reveal a number of cards without exposing a skull.

Bluff, lie, and pierce through the deceptions to expose the roses. Be wary, though: if you happen across a skull, the consequences are dire. One of the purest bluffing games ever made, 3-6 players in about 15 minutes.