Like in Stalker where the mutant dogs will turn tail and flee if they take too much damage or if you kill enough of their pack members. Red Dead Redemption's animals also ran away if a fight wasn't going their way.
Actually, Rockstar games are pretty good with this sort of stuff in general. I'm pretty sure you could shoot guns of of people's hands in RDR to make them put their hands up, or cause a fatal gunshot wound that would make them crawl around on their belly and call for help. Both GTA 4 and 5's enemies have injury states where they will take potshots at you with a pistol while bleeding on the ground or just passively clutch their wounds until they die.
I guess it wouldn't work in arcadey or linear games where the point is to kill everything on screen, but for anything more open-ended that tries to go for something approaching realism it'd be nice if the enemies you faced felt more alive and/or showed some basic survival instincts.
I meant that surrender rules would probably be clunky and metagamey if they were implemented. I can’t think of a TTRPG with defined surrender rules.
What makes me think of it is the Warhammer break/panic rules. If you haven’t played (and I haven’t in a while, so take with grain of salt), there are conditions where an entire unit of soldiers can lose morale, which costs you time and positioning while they regroup. Further, if they end up running away into the enemy, you lose the entire unit, which can be pretty disastrous as you might only field four or five units in an army.
Warhammer is a pure tactical game, so it makes sense, and is fun, to be able to use morale-breaking tactics in addition to simply out-fighting or out-maneuvering your opponent. However, if you had similar rules in a TTRPG, I could see it getting metagamey and get in the way of the roleplaying. Plus, it’s just another layer of things on top of initiative order, the action economy, saving throws, etc.
There are plenty of talented designers out there who might have games with decent morale/surrender/retreat rules, but my gut tells me that it’s probably more straightforward for the GM and players to agree that where it makes narrative sense, the GM won’t fight to the last NPC, and the players won’t be killed outright if they surrender.