Even though opponents are commonly described as being "killed", monsters usually inexplicably disappear after being defeated rather than leave corpses. Similarly, no one in your party really dies except if the plot calls for it. When your HP runs to zero, you're just knocked out, provided there's other party members still conscious to carry you away or heal you. (The monsters will eat you at their leisure if you are all knocked out.) Some games may even bump such characters back up to 1 HP once the battle is over. This only comes to play when a supposed permanently lethal attack/beat down/curb stomp/smack down/bullet storm/application of lethal force only causes someone to get KO'd or otherwise easily revived.
This might be to soften the idea you're basically going around killing wildlife, which could get morally sketchy in some places. It could also be so that when one of the characters dies because of the plot, one isn't distracted by questions like "Why don't they just use a Phoenix Down?"
This game mechanic is often complemented with following mechanics:
"Revive": The ability to bring a fallen teammate back into the action before the encounter is over.
Execute: The enemy ability to "execute" a knocked-out party member so that "revive" won't work on them anymore. Some particularly nasty enemies will have a kill-and-execute move.
Bleed out: A time limit on "revive" usage, after which the party member can no longer participate in the current encounter.
In Assassin's Creed I, Altaďr never actually dies in-game; instead, Desmond's actions while controlling Altaďr become so "de-synched" from the "real" memories that the Animus has to restart the simulation.
Batman: Arkham Asylum and Batman: Arkham City: You'd think that detonating a bomb next to a person and then bashing their head against cement would at least have a chance of killing them, especially after going hours without medical attention. But no, Batman doesn't kill, so they're just unconscious.
In Killer Instinct, characters were only considered "dead" if you used your finisher on them. In fact, killing (or not killing) certain characters altered your character's ending.
Quite often in Melty Blood. Shiki's power is killing something,no matter what.Period. Yet after being explicitly told he won the fight because of his eyes, his opponent is more along the lines of 'exhausted' than 'a cooling corpse' a few minutes later. Doesn't even seem to seem to leave normal knife wounds.
Mortal Kombat was one of the most notorious fighting games of its day because of its subversion of this trope. Not only was the fighting bloody as hell, but when the game called for someone to "FINISH HIM!" a player could do just that, pulling off a Fatality that could kill a character in all sorts of bloody ways.
Except for The Joker, who just shoots them (It zooms in so you don't see where the bullet hits, but the original versions had him either just shooting them in the head, or popping out a "bang" flag, causing their opponent to sigh in relief, before shooting the flagpole into the opponent's heart).
On a similair note, Strider Hiryu also dies at the end of a round like he would in his native game.
In One Must Fall: 2097 you can blow up your opponent real good without actually killing them. How? Everyone is, effectively, remotely-controlled robots. And then the game has a Double Subversionat the end of the single player story mode, where Kreissack is revealed to have actually had his brain transplanted into his robot's body.
Soul Calibur maintains the conceit that battles are decided by a KO, even if that KO is achieved by ramming a metal spike through a 16 year old girl's spine, tossing her into the air and bashing her head repeatedly with a gigantic axe.
First Person Shooters
Batman Doom. Well, you're Batman, and he doesn't kill. The enemies presumably just pass out from being struck with your batarangs, or from inhaling the smoke from your smokebombs, or from being... burnt to a crisp with your flamethrower?... yeah, it doesn't completely hold up.
The player in Deus Ex can Non Lethal KO opponents with riot batons, cattle prods, and crossbow-fired tranquilizer darts. Your character's brother encourages the use of these because he's working with the 'enemy'., While two of your co-workers encourage you to Kill 'em All. Surprisingly enough, they turn out to be the real bad guys.
The game also hints you along that you should be doing this. The quartermaster will scold the character (read: you, the person controlling the character) for killing too many people in mission one if, in fact, you do go on a shooting spree. Incidentally, you won't get any ammo from him if you do.
Nightfire for the PC uses this. Due to Executive Meddling on the part of MGM Interactive (who owned the James Bond license at the time), blood and death were no-nos. Thus, our intrepid hero only knocks people out. From a long distance. With a sniper rifle or rocket launcher. (Fair enough in the case of the game's default one-hit-'kill' weapon: it was tranquilizer pen-dart.) This whole situation becomes a little bit silly when playing multiplayer and you shoot someone in the head with your Walther P99. More than once. No blood, no death.
Your teammates in Rainbow Six: Vegas can be revived with a shot, but you can't unfortunately.
Star Wars: Republic Commando uses a similar system, in which downed squad members go into a coma-like state, from which they must be revived (with 50% health) with a defibrillator-shaped bacta dispenser. If all 4 of you are KO-ed or if your health reaches zero while you're cut off from your squad, it's game over.
Water Warfare goes the opposite direction in terms of absurdity—you will inexplicably faint from getting too wet. It's nonlethal because it's only water, but we're still not sure why it suddenly makes you drop unconscious.
Being drenched in extremely cold water, enough to make you pass out
In the reboot of Syndicate, your co-op characters will only be disabled. You can still hobble about, but cannot breach or fight. A teammate has to "reboot" you. If your teammates take too long, you'll fall to your knees in one place and be stuck there, but still don't outright die.
Hack and Slashers
In the Dynasty Warriors franchise most, if not all, characters carry lethal weapons (swords, spears, all manner of bladed weapon really) and ruthlessly hack away at lesser opponents, sending them flying. Nonetheless, your counter at the bottom of the screen is called a "KO counter", and whenever you beat an important character, they always say he was "defeated" or the like and not that you killed him, although there are exceptions to the "no death" aspect. (In some games, as well as the Samurai Warriors series, there are different cutscenes for a defeated-but-non-generic character depending on whether they're defeated but retreat, or die here. In Warriors Orochi, this is replaced by separate quotes for the generic officers.)
Notably, while the Empires side series of games still uses a KO counter, and defeated generals may get captured, a game option allows players to execute captured officers, and they may die of old age, leaving them really dead.
Also, in the Romance of the Three Kingdoms games, both options exist along with the option or whether or not officers can die in battle; in turn, Historical or Fictional gameplay options determine whether or not Plotline Death intrudes.
The Dynasty Warriors: Gundam games replaces the KO counter with a "Shot Down" counter. Which can be interpreted to include retreats from battle, mobile suits being disabled without pilot death, and killing blows. In game there are various Gundam universe based storylines where canon deaths appear, and main original storylines - who dies and who survives in these varies greatly.
City of Heroes links this to Thou Shalt Not Kill; heroes "apprehend", "arrest" or "stop" criminals, even if the hero does so with a broadsword, katana or high-powered rifle. Also, Paragon City has a municipal teleporter system which, among other things, is used to transport unconscious criminals directly to an unspecified law-enforcement facility, possibly the Zigursky prison in Brickstown, and unconscious heroes to the hospital.
Interestingly, the Expansion PackCity Of Villains lacks this explanation; while official heroes are presumably linked up to the aforementioned teleport system, the random thugs you meet on the streets of Mercy Island may well really die from your attacks. This idea is supported by the fact that while the police drones in City of Heroes are stated in their description as being tied to the teleporter system, their equivalent Arachnos drones in City of Villains are stated in their description as "vaporizing" targets.
In EVE Online, a destroyed ship will always spit the pilot out in an escape pod. However, a player who doesn't mind being universally hated can take out the escape pod too, reducing the pilot to however they were when they last updated their clone.
This goes for at least certain enemies too, if the integral article is any indication (that is, while in the Penultimate Fantasy Airship, it always says "You're fighting The Protagonist" indicating there is only one that you beat up repeatedly).
In zOMG!, players who lose all of their HP are considered "dazed". They can still slowly shuffle around the screen they're on or send chat messages, but can't change screens or interact with anything. Oh, and the ability that lets a player revive another player on the field is called "Defibrillate".
In Mabinogi Once the players Health is down to zero, they are knocked out and could be revived by a passer-by. Justified they cant die, due to the 'Milletians' (the player) being from another world.
Star Trek Online refers to zero-HP players and bridge officers as "unconcious" and allows you to revive them with "Cardiopulmonary Resuscitation" (=waving a tricorder at the guy). Even if the "unconciousness" was caused by the complete disintegration of the body by energy weapons. Even more absurdly, the game will list destroyed teammates in space battles as "unconcious," too. As if the ships didn't explode to tiny little pieces every time they reach Critical Existence Failure.
In Sonic the Hedgehog the enemies are robotic, but when destroyed a woodland critter of some kind is released, which merrily dashes away. So, not only are you not killing your enemies when you roll into them (potentially in a fireball), but you are actually doing a kindness.
Party members are only knocked unconscious in Avernum 4 and 5, though averted in the first three games, where party members die and have to be resurrected.
In the Star Wars: Knights of the Old Republic series, as well as Neverwinter Nights 2, party members reduced to zero HP are knocked out until all enemies are defeated, after which they struggle to their feet with one HP. However, if the entire party is reduced to zero HP, the game is over.
But subverted in Storm of Zehir, the second expansion to NWN2. As in pen-and-paper D&D, party members who are reduced to zero HP will bleed out and die if left untreated, at which point a raise dead or resurrection spell is required.
Mass Effect has this, but only for squadmates. If Shepard goes down, it's game over. Mass Effect 3 multiplayer mode additionally features bleed-out and execute mechanics: if a player isn't revived within a short time, they stay down until the end of the current wave; most enemies have the ability to execute a fallen player with the same effect; and some particularly nasty mobs can kill you good in one strike.
In Dragon Age: Origins, everyone gets back on their feet as long as at least one party member is still standing after the engagement is over, but each "death" leaves the character with an injury, i.e. a penalty on the stats, which can only be cured with specialized consumed items or high-level spells.
Dragon Age II replaces stat penalties with a penalty on your total health (you also get it from triggering traps, even if you are not killed), but otherwise plays it the same way.
Throughout the Dragon Quest series, monsters overcome in battle are described as "defeated". This rule does not apply to your own party, however - when a character is reduced to zero HP, the game announces, "(Character) dies". In addition, monsters dispatched by the instant-death Whack and Thwack spells are explicitly described as "killed".
In Dungeon Siege, characters losing all of their hit points will be rendered unconscious. If they continue taking damage, they'll get killed. If your entire party gets killed, the game is over. Of course, you can always revive your party members.
In EarthBound, the "defeated" message depends on the type of enemy you fight. Animals become tame, zombies and ghosts dissolve away, possessed plants or objects stop moving, and some enemies explode upon dying to deal massive damage to your party.
And human enemies come to their senses. All of these are justified in Mother and Mother 2, since all these things are under the influence of an alien with ultimate evil power on its side. When you defeat an enemy, you are usually just freeing it from the alien's mind control. Objects that stop moving are otherwise inanimate objects that simply revert back to their normal state. Party members will become unconscious instead of dying, but follow you as ghosts/angels until resurrected.
The Final Fantasy games moved from describing characters who lose all their HP as "killed" to "KOed" or "wounded" once they hit 16-bit. This may have been done in part to Hand Wave the "Why don't they use a Phoenix Down?" problem when characters die as a result of the plot. The spell which restores one from this state, though, remains "Life", "Raise", or "Rise".
However, sometimes an auto-controlled "Guest" character will join you in battle. If their HP drops to zero, they'll simply pass out and "dizzy stars" appear above their heads without a death countdown timer.
In Final Fantasy Tactics A2, it is confirmed ingame that characters can die. But as long as there is a soul trying to come back alive, and a fitting container (preferably the person's own body), the person can be brought back to life with magick (Raise spells, Phoenix Downs). All battle-kills are recorded as KOs however. It goes even farther when an Alchemist transmute a weakened enemy into a Potion or a Phoenix Down and they're still treated as not dead. Even if you use the item.
In Final Fantasy XII it's shown that monsters don't always die when they run out of HP. One mission has you hunting someone's pet turtle that has become giant due to being in a Magicite Mine. After you defeat him he is explicitly shown to have survived and shrunk back to normal size when you talk to his owner.
Also averted with some Hume bosses, who can be defeated by knocking their HP down to 25%, rather than all of it.
Final Fantasy XIII-2 follows suit, except that once the party leader falls, the control automatically switches to the second party member (out of two available in total). If the second party member falls, however, the game's over, even if the summoned monster knows the Raise spell.
In Freedom Force, everyone is only knocked out (even Mooks). It's not too out of place for people like Minuteman, who hits people over the head, but considering other people have powers like shooting fire from their fingertips, throw bombs filled with acid, or shoot energy out their chest, and they can do things like push people off buildings, hit them with lamp-posts, and throw cars at them, it gets kind of sketchy that no one dies except for Plotline Deaths.
In the Golden Sun series, both monsters, characters, and bosses are described as being 'downed' when their HP runs out.
In Lands of Lore: The Throne of Chaos, it is not clear whether party characters with 0 HP are supposed to be incapacitated or dead. One one hand, characters with 0 HP can still talk and manipulate items, suggesting that they are just too wounded to fight. On the other hand, they can only be healed with magic and special items, are unable to perform most actions, and any poison effects they have are removed, suggesting they are dead.
Legend of Mana plays it straight: KO party members automatically revive after a set amount of time provided the other party member (or even your pet monster or golem) is still standing. Surprisingly, though, this rule applies to the boss battle against Sierra and Vadise, who also revive from KO after a set time.
MARDEK has the KO'd/revive with one HP version. Monsters always go poof, even the mirror-image four-man-band who call themselves the World'sSaviors, who should be able to revive each other the way your own guys can.
Despite doing battle with massive untamed wyverns, the hero in Monster Hunter never dies. Should he or she run out of life, a pair of cats wheel him or her back to camp and unceremoniously dump out the body with full health. However, running out of life cuts your reward by one-third, and after three KOs (resulting in a reward of nothing) you immediately fail the mission.
This is most explicit in the Pokémon games, where every defeat is a KO, and when you're defeated you black/white out temporarily. You are also forced to give a portion of your money to the person who beat you. Oddly enough, in FireRed, LeafGreen, Diamond, and Pearl versions, after being defeated your character is described as running to the Pokémon Center, so the fact that your character blacks out is now utterly pointless. Also note that in Generation I, being beaten by a wild Pokémon also cost you half of your money (which later games have explained as being lost in the confusion).
It's been noted by the creator himself that he preferred a nonlethal KO system because of the abundance of pointless violence in many video games.
Lampshaded by the Rival in the Pokémon Tower, where he notes that while your Pokémon don't look dead, he can settle for making them faint.
It becomes a bit odd when you take into account moves like Selfdestruct or Explosion, which cause the user to "faint". What exactly has exploded? Pokémon Snap shows the user creates an explosion that blow it and the attacker away from each other but leaves the user spent. Supposedly the original idea was to say "unable to battle" but fainted took less text.
Some fans avert this for a Self-Imposed Challenge. Also averted in Pokémon Special. Sure, battles aren't inherently dangerous... but some people are just evil enough to tell their Pokémon to actually hurt others.
Also averted straight to hell by Cipher, whose idea of dealing with interlopers involves taking down their Pokemon, then beating the offender black and blue! You can see it happen best when Dakim nails Vander in the solar plexus - a rare case of human-on-human violence in the franchise.
Your party members will always go into a Non-Lethal K.O., though, even if they took Body damage. There are plenty of enemies that are still alive in cutscenes after you battle them, as well, regardless of what method you used to defeat them.
Both played straight and averted in Sa Ga Frontier 2 - your characters, if they are taken to 0 HP in battle, will simply collapse and get up with a small number of HP and one less LP after the battle. However, there are attacks that do LP damage, and if a character's LP hit 0, they're dead. Permanently. FOR THE REST OF THE GAME.
Unless otherwise mentioned in dialogue, no one seems to die in Super Robot Wars. Unless its a special mission, whenever your soldiers are shot down, they simply eject and you have to pay to repair their unit. The same courtesy is also given to your enemies, as a large amount of their Reduced To 0 HP dialogue involves them trying to eject.
Taking this into consideration, it seems really strange how so much of your characters' dialogue upon being shot down refers to being killed.
Games using the Gamebryo engine (e.g. The Elder Scrolls IV: Oblivion and Fallout 3) have an NPC flag called "Essential." Since some NPCs are vital to the main quest, they are set to essential so they can't die; when their HP is reduced to zero, they fall down and a message displays "(NPC) is unconscious." The NPC will wake up after a short time.
Fallout: New Vegas has no essential NPCs except Yes Man and your current companions (and if you play in Hardcore mode, just Yes Man). It also incorporate non-lethal damage with a few weapons (boxing glove variants, cattle prods, and beanbag shotgun rounds), but unconscious enemies can't be looted and always get up after thirty seconds, which rather defeats the point; you may as well just sneak by them entirely. As these weapons all apply the same amount of fatigue regardless of enemy DT, they're really more useful for stunning your opponent to kill them while they're unconscious.
The original Gothic put an interesting spin on this trope: if you fight monsters, they always kill you good, and you return the favor. However, when fighting humans, both sides deal a Non-Lethal K.O. first, with an option to execute the downed enemy later. The point is that a downed enemy can be looted like a dead body without incurring any penalties for murdering them—however, that also applies to the downed Player Character, so the enemies who don't immediately execute you will search your pockets and strip you of any valuables they find.
In the Mario & Luigi series, the Mario bros and any named characters merely get knocked out or hurt if they run out of health in battle, with the Elite Trio in Dream Team even mentioning it by name (saying that all three have to be K Oed at once for Mario to win). Possibly averted for anyone not quite that important to the storyline, who simply explodes and is never seen again after the battle.
In Star Fox 64, your wingmates will be "downed", I.E., say a small line with the "crossed wrenches" sign over their picture, then leave the mission. They sit out the next one, then reappear. You, however, clearly explode when your shields fail.
Also played straight in Assault. Averted in the SNES game, where your wingmen can die for real.
Spellcard System rules in Touhou exist for this explicit purpose. Otherwise, the One-Hit Kill abilities of most high-level youkai would instantly end Barrier Maiden Reimu's career. (She even fights a ghost capable of killing with nothing but thinking about it. Imperishable Night proves she can do it without other people even noticing she's trying.)
The first Bangai-O game plays this for laughs, since recurring bosses tend to survive their mechs exploding (to Riki and Mami's confusion). Bangai-O's pilots aren't as lucky.
In AaaaaAAaaaAAAaaAAAAaAAAAA!!! – A Reckless Disregard for Gravity, when you hit something, even if you're falling from a height equivalent to several skyscrapers, you'll survive, but with most of your bones broken. Sometimes the game is rather specific in telling you which bones are broken, e.g. "You broke ten of your fingers".
In Animal Crossing, If the player is attacked by a scorpion or a tarantula, they will pass out and awaken in front of their house.
If your patient's vital levels reach zero during an operation in Trauma Center: Under The Knife, he or she ostensibly doesn't die; another doctor simply takes over and the player character is said to have quit in shame. Near the end game, however, this happens less and when it does it is implied that the other doctor will fail. These scenes also occasionally imply that the main character killed himself from the shame, instead of just quitting.
In Spore, if your creature's ship explodes in the Space stage, you don't die, but is revived through cloning.
Speaking of immortal wingmates, in Star Wars: Rogue Squadron wingmates who are downed will land on the surface but never will die. This even occurs during the Death Star level.
In the campaigns of Age of Mythology and its expansion Age of Mythology: The Titans, when the heroes are "killed" they are unconscious until one of your units gets close to them, at which point they revive with low health.
Even in Fire Emblem, a game where characters who run out of HP permanently are dead for the rest of the game's campaign (That is - can never be deployed in combat again for that save file. Ever.) in later games, plot relevant characters who lose all Hit Points are depicted as simply being too heavily wounded to continue fighting. This is presumably so that plot-important PCs can still take part in conversations outside of battle. On the other hand, if any of your Lords lose all their Hit Points, they will die and the game is over.
Non-plot important characters however, often die complete with death speech.
Exception: the tutorial campaign in Blazing Sword. Any characters used here return in the main campaign whether they were injured or not.
There are endings for these characters that explain what happened after the campaign. A character's story changes slightly if you lost him or her during one of the battles.
Noticeable is that in Path of Radiance and Radiant Dawn characters injured this way don't fade away like dead ones do.
Awakening allows the player to follow this trope with their own units. "Casual" mode lets KO'd characters fight again in the next battle, while "Classic" mode utilizes Final Death. The exceptions are Chrom, your created character, and a second Lord who shows up later on.
Even when their Angel Wings blow up in the middle of space, the Angels under your command in the Galaxy Angel gameverse are simply KOed, brought back to base after the battle, and only get a little ticked off at you for giving them sucky battle plans. The third game actually used this shot-down-but-not-killed device as a plot point. Your Angels probably have better defences than you do; if the Elsior, Luxiole or Brave Heart goes down, it's over.
In Zone of the Enders: the Fist of Mars, your mechs explode when their HP is reduced to 0. When that happens, they're out for the rest of the stage, but the characters piloting them are still alive, and they do come back next stage.
Everyone who you fight are either Mecha-Mooks (unmanned) or shows enough mercy to allow the pilot to escape. Even Pharsti calls Edge out on being a technical pacifist and he supposedly follows it until his Midseason Upgrade where he supposedly kills Ned after he threatened to kill several children with explosive collars and done so already with one pilot.
Subverted in Valkyria Chronicles: each member of your squad has a unique voice, personality, appearance and story, and if they die on the battlefield because you suck as a commander, they stay dead forever. What makes this so shocking is the game's cartoonish graphics style and (otherwise) relatively lighthearted and cheerful storyline. The second game in the series follows this trope, though: the worst that can happen to your characters (outside of cutscenes, of course) is being "hospitalized", which means they can't join your next three battles.
In Mount & Blade your character can't be killed in battle; instead, you will be knocked unconscious and either captured by the enemy, or rescued by your allies.
In League of Legends, when you kill an enemy champion, they are revived by the magical energy of the battlefield. Then again, Cho'Gatheats his opponent, Fizz has a shark eat them (small opponents are swallowed whole) and Thresh claims their soul.
In the Advance Wars series, Commanding Officers are apparently off-limits for either side's troops to shoot at. At first you might think this is because the COs are far behind the front lines coordinating the battle by radio, but multiple "mission failed" cutscenes in story mode make it clear this was NOT the case. Hell, many story mode scenes have named characters storming into each other's offices, guns drawn, yet the loser almost always escapes without a shot being fired by either side.
In Siren, this trope applies to the enemies, the shibito. Instead of being killed, a defeated shibito will only stay down just long enough for the player to escape before getting back up.
Clock Tower: Bobby being a supernaturally empowered demon child, anything Jennifer does to him (poison gas, using a murder of crows to attack him, tricking him into falling down a hole) will only have him down for a minute or so, or until she leaves the map (whichever comes first).
100% Orange Juice: If the character's HP hits 0, s/he cannot move, but can roll the die to get back up (roll equal to/higher to revive).
In Toon: The Cartoon RPG, the player characters are cartoon characters, who as everyone knows can take massive amounts of abuse without getting killed. So instead of dying when they run out of hit points, they Fall Down, and are taken out of action temporarily.
In Dungeons & Dragons 3rd Edition, a character reduced to zero hit points is disabled and falls unconscious. After that, you have ten turns to stop their decline with a healing spell — they gain a negative hit point each turn, and when they hit -10, they die. Note that a powerful blow which reduces a character below -10 HP in one strike will kill them instantly.
4th Edition changes the death threshold from -10 to negative your Bloodied valuenote That is, 1/2 of your Maximum HP.
2nd Edition had the -10HP rule as an option at least as well. Baldur's Gate used this with spectacular effect, where foes...or characters, including sometimes the hero...got "chunked" if they fell below -10HP in a single strike.
GURPS has had a rule similar to 4e D&D since its 2nd edition: characters are weakened at low HP, lose consciousness at 0 HP (but they can make a roll to keep standing), and at -HP equal to their standard healthy HP, they start rolling to resist death (at -5x HP, they die even if they withstood all rolls). Again, Chunky Salsa Rule applies; a character whose corpse is damaged to -10x HP has nothing left to revive, he's just turned into hamburger.
The Teenagers from Outer Space RPG is based on slapstick anime, and characters who run out of "Bonk" points will recover in a few turns.
Mutants & Masterminds defaults to the conceit that the player characters are dealing non-lethal damage unless otherwise specified to reflect the Silver/Bronze Age setting where heroes didn't kill.
Invoked as a way to justify how named characters can be "killed" in Warhammer 40,000 as well as the player's own self-made characters. This way players don't have to find ways to justify how a commander with a survival deficiency somehow appearing in multiple battles, but gets kind of ridiculous when the character can take a planet-vaporizing blast and was only "knocked unconscious". Also comically used in various one-hit KO spells, where the combatant can be rendered as either a deformed blob of flesh, a gibbering idiot, locked in a box, or a squignote goblinoid pig, for those unfamiliar with the franchise.
Brawl in the Family gives a parody/humorous deconstruction of how this is in the Pokémon games by taking it to it's logical conclusion. Can be seen in full here.
Wide Open Sandbox
Bully, which is often described as a Lighter and Softer version of Grand Theft Auto, has this. Since Hide Your Children won't work in a game where most characters are children, NPCs (as well as the player) can only be knocked out instead of killed. The gameplay mechanics are pretty much the same. They even fade away after a while and will later respawn alive and well.