Russian roulette -- My comments: We've seen this in many movies but didn't know what it's called.

If someone plays Russian roulette, they fire a gun with only one bullet at their head without knowing whether it will shoot them.

a very dangerous game of chance where each player aims at their own head with a gun that has one bullet in it and five empty chambers (= spaces where bullets could go)

an act of bravado consisting of spinning the cylinder of a revolver loaded with one cartridge, pointing the muzzle at one's own head, and pulling the trigger