russian roulette

Russian roulette
    n 1: a stunt in which you spin the cylinder of a revolver that
         is loaded with only one bullet and then point the muzzle at
         your head and pull the trigger
    

Russian roulette \Rus"sian roulette\
   (a) An act of bravado played by loading one bullet into one
       chamber of a revolver in which the cylinder has five or
       six positions, spinning the cylinder (thus moving the
       bullet randomly to one of the six positions of the
       cylinder), pointing the gun to one's head, and pulling
       the trigger. If the bullet is in firing position, the
       "player" is usually killed. Such a "game" may be played
       on a dare, or, in some places, as part of a gamble.
   (b) (Fig.) Any dangerous act resembling Russian roulette in
       the acceptance of a high risk of serious negative
       consequences, usually unnecessarily. "The congress is
       playing Russian roulette with the economy by enacting
       such large tax reductions without spending cuts."
       [PJC]