The combatants could be school classmates, coworkers, any two people who want to settle a dispute fight. It’s usually two fighters of the same gender, usually using fists to decide a winner, although there are usually exceptions with each rule that could apply. Sometimes UFC or wrestling like maneuvers wind up ending things, like an unscripted body slam or a chokehold.
From what I’ve seen, the more of a mismatch the fight is, the more memorable it winds up being. We all seem addicts to the spectacular failure, right? If a fight ends in a one punch knockout, with the loser snoring on the concrete, we think it’s something funny, and not the damage done that is likely permanent to the defeated fighter.
But I guess everyone has their pornography, even if it isn’t pornographic.