The rules are simple enough. One round is placed in the chamber of a revolver. The chamber is then spun in sort of a mock version of roulette. Once the chamber comes to a complete stop, the player usually places the gun to his head and pulls the trigger, knowing that the gun probably will not fire a bullet but not being completely sure. The uncertainty is what adds to the sense of suspense and, for some, fear.
Now let's look at the game more logically. Say there are six chambers, only one of which has a round. You may think the chances that the revolver would fire a bullet would be one in six. But assuming that all is well-maintained and lubricated, gravity will naturally pull the chamber with the bullet in it down, resulting in a higher chance of survival for the player. That is also assuming, of course, that all other things are equal and the cylinder is allowed to stop on its own.
But still, please don't push your luck.
