Although it's always hard to prove a negative, Russian roulette was not prevalent at all during the war, neither by North or South Vietnamese soldiers or by American soldiers. There are no documented cases of American soldiers being forced to play Russian roulette while being prisoners of war.
Aside from that, was Russian roulette a real game?
Origin. According to Andrew Clarke, the first trace of Russian roulette can be found in the story "The Fatalist" of 1840, part of the collection A Hero of Our Time by Mikhail Lermontov, a Russian poet and writer. ... The game spread among Russian garrison officials, becoming a foolish courage challenge.
Either, why does Nick play Russian roulette? At the end of the film the main character Mike goes back to Vietnam in order to convince Nick to come home, but Nick not only doesn't talk to Mike, he spits in his face. Mike then plays Russian Roulette with Nick trying to remind him of home, but Nick only says "One shot", before shooting himself in the head and dying.
On top of, what are the odds in Russian roulette?
The odds of randomly happening upon the chamber with the bullet in it is question of simple math: a one in six chance, which is approximately a 17% chance of dying on each turn. Of course, that translates into about an 83% chance you'll survive.
Is Russian Roulette illegal?
Of course it is NOT LEGAL, at least in civilised and advanced societies which have Laws to protect citizens from harm, such as suicide which “Russian Roulette” ultimately is for the winner, or loser, but I guess that is relative to whom pulls the trigger last.