T.O.D.
This wasn't really a play, but a short story by Evan Hunter (THE BLACKBOARD JUNGLE). As I recall, the title was THE LAST SPIN.
Back when I was a junior in high school, my late friend, Gene Rice, discovered this short story about two teens from rival gangs who are chosen by their respective gangs to play a game of Russian roulette in order to avoid an all-out gang war. The survivor's gang wins the territory.
The two kids start out as enemies, but as they pass the gun back and forth, they bond and, just before the final trigger is pulled, they decide to "screw the gangs". Unfortunately the last chamber is not empty.
I adapted the short story into play form, a rather simple task, and Gene and I presented it in front of the Drama class. It went over so well, and the teacher and school principal considered it such a good life lesson, that over the next few weeks, they brought different classes in to see our play.
We were a hit!