Simple, yet tense. Nice. This is a very fun game. It'd seem like Russian Roulette wouldn't have much potential, but playing enough will point out some simple objective math to maximize probability of survival. I see more potential behind this game in the form of cinematics, writing, and maybe the addition of more rules or players.
Want to maximize your survival?
ALWAYS try to shoot your opponent UNLESS...
1- ...it's a 1/3 chance, at which point, spin the cylinder.
If you try to shoot them when there's a 1/3 chance left, it WILL be a death sentence. Picture this: *click 1*
*click 2*
*click 3*
Now you have the gun, with only 1/3 of a chance of it going off. If you point it at them, more likely than not (2/3, of course), they'll survive, and that will be the last time the gun will be pointed at them.
*click 4*
Checkmate; You're forced to turn the gun onto yourself for 1/2, and even if...
*click 5*
...you actually survived that, you're forced to hand the gun over to your opponent, who, given the 1/1 chance, WILL point it to you and...
*BANG*
NOTE: If you're at 1/3, but you have already used your "cylinder spin", then point it at yourself, (in the off-chance of them getting nervous and using THEIR cylinder spin);
THE MATH BEHIND THAT IDEA: If you point it at them, you'll have 1/3 of a chance of killing them, but then you're "checkmated" so to speak (1/3 chance of killing them translates to 2/3 chance of you dying). BUT... If you point it at yourself, you'll take 1/3 of a chance, and the gun will go to them, who will either point it at you for 1/2 of a chance of you dying (which, after the math, still equates to them facing 1/3 of a chance at death, and you having taken 2/3 of a chance anyway) OR they'll decide to use THEIR cylinder spin (the objective in turning it on yourself), bringing the odds back in your favor (they probably won't use a pure "always try to shoot the opponent" tactic, AND... if they did, it'd be very very close to the previous 50/50 risk anyway)
2- ...it's a 1/2 chance, at which point, spin the cylinder.
If you continue the "always try to shoot the opponent" tactic, your odds will be > 1/2 (even if they also always try to shoot you as well. This is due to the fact that you always go first in this game).
NOTE: If you've already spun the cylinder, obviously, try to shoot them, as it's unlikely that they'll use their cylinder spin or commit suicide when they have a 1/1 chance of killing you, lol...