Russian roulette is a deadly game played with a revolver. In the game, there is only one bullet in one of the six cylinder slots of the revolver. The person then closes the cylinder, spins it, places it against their head or sometimes inside their mouth and pulls the trigger. The person therefore has a one-in-six chance of killing themselves.
It is done either for bravado, boredom, suicide or other reasons. It sometimes used in fiction as part of interrogations, where the interrogator asks the suspect if he wants to play a game of Russian roulette and palms the bullet.