The primary piece of equipment used to play modern Russian roulette is a toy gun that has a 1/6 probability of activating when the trigger is pulled. The gun may be a dedicated device, or it could be a video game light gun connected to a computer programmed for Russian roulette simulation.
All players put money in the pot. Each player in turn points the gun at their head and pulls the trigger. If the gun activates, the person holding the gun is eliminated from the game. The last player remaining wins the pot.
Assuming a six-shot revolver and that each hole is equally likely to be under the hammer, the probability of losing in the first round is 1 in 6 and the probability increases with each trigger pull. On the 6th trigger pull the probability of losing is 1 in 1 (100%).
|1||1/6 = 0.166..|
|2||1/5 = 0.2|
|3||1/4 = 0.25|
|4||1/3 = 0.333..|
|5||1/2 = 0.5|
|6||1/1 = 1|
If the cylinder is spun after every shot, the odds of losing remain the same, 1/6 each time the trigger is pulled; in this case, in a two-person to-the-death game, it is better to go second (if the first person loses, the second person wins, even if he would have lost on his next move — this is equivalent to the house advantage in blackjack, where the house wins if the player busts, even if the dealer himself also is going to bust).
Video: Russian Roulette