->''"And God spake all these words, saying...\\
[[TropeNamers Thou shall not kill]]."'' [[note]]The phrase actually translates to "Thou shall not murder." "Thou shall not kill" is an Elizabethean translation, and there's been some semantic drift since.. It would be strange for the Old Testament to forbid every manner of killing, given the times when God is said to have ordered the Israelites to kill e.g. wipe out the Amalekites.[[/note]]
-->-- '''Literature/TheBible''', ''[[Literature/BookOfExodus Exodus]] 20:1,13''

Ending a life is [[BackFromTheDead usually]] a permanent thing. There's no way to say "I'm sorry", or to make up for it later. And for some people, killing is a line they ''will not cross'', no matter how much the death might serve the greater good (or, in some cases, the greater evil). "He needed killing" is not in these people's vocabulary.

This is common in works with BlackAndWhiteMorality, but even appears in works with GreyAndGrayMorality. In the latter, it's sometimes the only way to tell the "good" guys from the "bad" guys.

[[WhatMeasureIsANonHuman Opinions differ on how this applies to sentient life other than humans.]] In general, it's still up to BigDamnVillains to kill other villains. It's perfectly fine to [[ImmortalLifeIsCheap "kill" immortals though]] as it is to kill the undead. The MercyKill sometimes winds up as an exception. KarmicDeath, SelfDisposingVillain, and HoistByHisOwnPetard provide alternate ways to kill off villains without forcing the hero to get his hands dirty.

Thou Shalt Not Kill is closely related to JokerImmunity. Whilst many writers believe a never-kill creed makes the hero more likable and righteous, on another level it might simply be a plot device to prevent the hero from killing off popular recurring villains. Related is PacifismBackfire, where their reluctance to fight (or to kill as in this trope) may cause JokerImmunity. This trope is more common in serial fiction, such as TV shows and comic books, rather than one-shots like movies. In action movies it is common and acceptable for the hero to kill the villain because there is usually no planned sequel for the villain to appear in.

With superpowered characters, attitudes toward no-kill policies range from utterly ignoring it (such as the protagonists of ''ComicBook/{{Watchmen}}''), to strict adherence except in extreme circumstances (such as Franchise/{{Superman}}). One rationale is that if, say, Superman were to kill a bad guy in one story, why wouldn't he simply resolve all situations by, for example, incinerating SelfDemonstrating/LexLuthor with his heat vision on sight.

Whatever the moral case is, this trope is often used to show off the hero's incredible precision, whether it be with a fist or a gun. This can include things like [[BlastingItOutOfTheirHands separating the mook from their weapon with a precisely aimed bullet]], or possibly [[TapOnTheHead knocking an opponent out]]. Whatever the case, their non-lethal attacks are due to their incredible skill. Note that this often a case of RealityIsUnrealistic as many of these attacks are very capable of causing serious injury or death.

This is TruthInTelevision. In general, there are very few humans who can stand the thought of ''truly'' ending the life of another human without military training. The military has developed many studies over the years to evolve the best training curriculum to dehumanize the "enemy" and enable their soldiers to kill enemy soldiers. Even then, when a soldier is tasked with actually shooting a bullet that would end the life of another human being...many would rather intentionally miss. It is this (strength, in the case of all human life, but weakness in the case of human life with an opposing ideology) that makes modern militaries attempt to make the enemy soldiers appear as "unhuman" as possible. Otherwise, despite how some may make boasts to the contrary, in truth most people - including law enforcement - are loath to take a life unless absolutely necessary in the course of self-defence or the protection of others.

See also KickThemWhileTheyAreDown, ActualPacifist, RecklessPacifist, TechnicalPacifist, MartialPacifist, NonLethalWarfare, WouldNotShootAGoodGuy, RestrainedRevenge.

----
!!Examples:

[[foldercontrol]]

[[folder: Anime and Manga]]
* In ''Anime/DragonBallZ'', the main character Goku strongly personifies this trope (so much so that is almost considered a RunningGag) as he refuses to kill even the most evil opponents. He lets Piccolo Jr., a character who was at that time considered a demon who also just tried to kill him live, he tries to let his brother to live after threatening his son and rest of the population of the planet, and he even tries to let Frieza, a genocidal alien [[ForTheEvulz who destroys planets for fun]] and just killed his life long best friend, live. It is odd because he was willing to kill an entire mook army as a kid and eventually is willing to kill evil opponents later in the series, but for a long period of time in the middle he insist on giving everyone a second chance.
** That being said, he still tried to kill Frieza without hesitation when he tried to attack him. Frieza was just incredibly tough to survive it.
** It should also be noted that one of the reasons he did not kill Piccolo Jr is because if he did Kami would also die along with the Dragon Balls. Frieze was also more of a case of CruelMercy.
* ''Manga/OnePiece'' plays with this trope; the main character, Luffy, will not kill anyone, but it's not out of niceness. [[CruelMercy He just thinks it's a worse punishment for them to live, and watch their dreams get shot down in flames by him and his crew]].
** Other members of the crew, namely Zoro and Robin, are willing to kill off their foes. They never actually ''do'' end up killing anyone except [[WhatMeasureIsAMook some incredibly marginal characters]], but they're definitely not holding anything back.
** ''4Kids'' forces this on their ''Manga/OnePiece'' dub. One example was how Lucky Roo shoots a bandit in the head, but the dub has Shanks saying that "And when he wakes up, tell him it's a cap gun!"
** Fishman pirate Fisher Tiger held this as a strict rule among his Pirates of the Sun. It wasn't out of altruism. Instead he felt HumansAreBastards and didn't want his crew falling to that level. He also hoped to avert encouraging a CycleOfRevenge.
* Vash's quest to live without killing is essentially the main subject of ''Manga/{{Trigun}}''. Not only does he strive to live without killing, he also attempts to spread this philosophy to others, including villains, even at the cost of his own health and safety. Other times, he begs characters who have a just cause for vengeance to forgo it and let things lie. However, he IS forced to take a life at one point to save others. This does not cause him to renounce his goal to save as many people as possible however. That said, with how heavily the series points out how this has ''cost'' Vash, physically and emotionally, and the numerous dismissive or critical actions of other characters, and the question the series raises itself that Vash and Knives may essentially be following childish philosophies without any mental maturity, it's not too hard to argue that the series is a deconstruction of this trope.
** [[InvokedTrope Invoked]] with Wolfwood.
-->'''Vash''': "Thou shalt not kill, remember? What kind of churchman are you?"
* Rushuna of ''Anime/{{Grenadier}}'' does more or less the same thing (with more {{Gainaxing}}).
* ''Anime/MazingerZ'': The original manga plays with it. In one chapter, three [[{{Mook}} Iron Masks]] sneak in Kouji's home to try murdering him (it must be stated in the manga they were WAY more competent than in the anime, where Law of ConservationOfNinjutsu held true). Kouji hesitates about killing them even after finding out [[spoiler:they are corpses reanimated with a mechanical brain.]] When he finally gets forced to kill one of them in self-defense he suffers a HeroicBSOD (he remains kneeled, shaking and trembling), and later he is wondering if he is a murderer now. However another character reassures him it was self-defense, lampshading this trope as "the defense of a manga protaganist".
* ''Manga/RurouniKenshin'' has a similar plot, where the main character (a former assassin) has sworn to never kill again, and uses a specially designed sword that faces the wrong way, so opponents won't get cut by it, normally (he keeps an edge so as to be able to cut inanimate objects by flipping the blade). Get him to unleash his SuperpoweredEvilSide, and you may have a problem.
* In ''Manga/{{Claymore}}'', the Claymores are forbidden from killing humans, even if it's an accident or is done to protect another human. The punishment is immediate execution. However, there have been Claymores who are perfectly willing to kill humans. For example, [[spoiler: Teresa]] slaughtered a group of bandits to protect [[spoiler: Clare]] then went rogue and there was Ophelia who took sadistic pleasure in torturing and killing humans and fellow Claymores, but was just sure to kill all the witnesses so no one would find out.
* In ''Manga/IkkiTousen'', Sonsaku Hakufu refuses to kill her rivals, saying that [[BloodKnight she only wants]] [[BoisterousBruiser to fight them]] but not take their lives.
* In ''[[Manga/DetectiveConan Detective Conan/Case Closed]]'', Conan/Shinichi always refuse to let a suspect end up dead, even the suspect tries to kill him. He would even try to save the suspect's life even if it risks his own life.
* ''Manga/MahouSenseiNegima'', bizarrely enough, has a ''villain'' (well, AntiVillain) with a Thou Shalt Not Kill code, though he was willing to break it if his opponent was dangerous enough.
* Nanoha Takamachi of ''Franchise/LyricalNanoha''. Very skilled at using [[StunGuns Magical Damage]], which lets her create a lot of flashy explosions without ever killing anyone, even sentient non-humans. By contrast, the Wolkenritter have no personal qualms about using lethal force when needed, but they also followed this code when they were [[HeroAntagonist antagonists]] in the second season since they didn't want Hayate's name to be defiled with blood.
** One has to also understand that in a world where DefeatMeansFriendship is the 45th law of physics, exterminating one's enemies permanently can be downright wasteful.
* The ''Manga/RaveMaster'' and his [[TrueCompanions allies]] hold to this as a central philosophy. While they don't shy away from doing it when it's necessary, they will generally do all in their power to resolve their battles without killing.
* In ''Manga/{{Bleach}}'', most of the main cast members [[{{Shinigami}} who aren't dead]] at least ''try'' to follow this, save for when fighting run-of-the-mill [[TheHeartless Hollows]]. [[TheMedic Inoue Orihime]] not only hasn't harmed anyone seriously since her powers first emerged, but ''can't'' due to her personality. Unfortunately, she tends to believe that this makes her a burden on her friends, despite that [[spoiler:she can ''[[RealityWarper reject reality]]'' to the point where she can heal a corpse with half of their brains blown out. The fact that it was someone who had shown up simply to try and ''torture'' her for no reason other than spite is just icing on the cake]].
** Oddly enough, Ichigo didn't kill a single Arrancar in his invasion of Hueco Mundo, at least not consciously; he let [[BloodKnight Grimmjow]] live, his SuperpoweredEvilSide took out [[NobleDemon Ulquiorra]], and the mooks he cut down were revealed to be fakes generated by another arrancar. This is somewhat jarring when compared with Fake Karakura Town, where both of the Espada's {{Token Good Teammate}}s are cut down without anybody batting an eye.
*** It's debateable whether Ichigo avoids killing because he's following a code, or because he just doesn't feel like it. In one arc the villain is revealed to have altered the past of Ichigo's friends and family, making them believe him to be their friend and turning on Ichigo when he attacks him. Once Ichigo hears the details, the first thing he asks if if they'll change back if he kills the person who did it. He looks quite scary when he says it.
*** Ichigo himself has issues with this. He has no will to kill anyone, and it's even [[LampshadeHanging lampshaded]] by Urahara. During his fight with Renji, he gets over it. Renji still lives, but Ichigo was able to put the thoughts behind him and kill him if necessary.
* Tenma's motto, often tried in ''Manga/{{Monster}}''.
* ''Manga/YuYuHakusho'' plays with this trope when Yusuke fights Doctor Kamiya, a follower of Shinobu Sensui. Kamiya brings up that Yusuke has never killed humans before, only demons, and thus believes that Yusuke is going to hesitate before trying to kill him. [[spoiler:He doesn't, and is only stopped when Kamiya takes a passing nurse as a hostage. Turns out the "nurse" is really Yana in disguise, and Murota informing Yusuke that the Doc was lying about a cure and really planned to finish him off, prompts Yusuke to cross the line. Killing Kamiya breaks his psychic territory and saves everyone in the hospital, and Yusuke's conscience is eased when Genkai quickly revives Kamiya with a chest compression.]]
* [[spoiler:Abel]] from ''LightNovel/TrinityBlood''.
* Somehow, holding to this trope makes Manga/FrankenFran ''[[FateWorseThanDeath even scarier]]''.
* In ''Anime/DigimonAdventure02'', the Digidestined are afraid of killing Digimon, and avoid it whenever possible (unlike in the first one, when fighting the forces of Etemon, Myotismon, and the Dark Masters). The only exceptions are Control Spire Digimon (as they are not considered "alive"), Kimeramon (who was created by the Digimon Emperor), [=MaloMyotismon=] (as he is pure evil and the main villain behind everything in Season 2), and Airdramon (for unknown reasons). They are forced to kill [=SkullSatamon=], [=LadyDevimon=], and [=MarineDevimon=], and Yolei and Cody are shocked when this happens (though Cody knew they'd have to destroy [=MarineDevimon=]), though TK and Kari reassure them it was the right thing to do.
* ''Manga/FullmetalAlchemist'': Main character Edward Elric refuses to kill to achieve his goals, even Homunculi. Still doesn't make him any less {{Badass}} by any stretch of the imagination. [[spoiler:Just look what he did to Pride. In fact, the closest he comes to killing anyone is when he punches through Father's chest after regaining his arm, and even then, he didn't actually die...instead, what happened to him was [[FateWorseThanDeath far worse]]]].
** In the final story arc [[spoiler:Mustang and crew also subscribe to this policy, at least in regard to human enemies. However, their allies, the Briggs soldiers, do not.]]
* In ''Manga/{{Saiyuki}} Gaiden'' the heavens have to abide by this rule and do so to varying degrees. Konzen is vegetarian, however Kenren thinks it's fine to eat fish but has to fight in the army with a stun gun...yet Tenpou has a katana but presumably still obeys the rule. Of course [[spoiler: all of that goes out the window in the end]]. Averted entirely in the main series; the main characters kill many, many, ''many'' youkai on their divinely-ordered trip to India.
* Roger Smith in ''Anime/TheBigO'' lives by a self-imposed code of ethics. It appears to trend towards not killing people as he is very reluctant to use any form of firearm, and when pushed to use one will shoot at objects rather than people.
* In ''Anime/TigerAndBunny'' the Heroes employed by Hero TV refrain from killing criminals. However, the public seems to have gotten tired of this "soft" method of dealing with criminals. When a VigilanteMan NEXT calling himself Lunatic starts killing criminals, the public ''loves'' him.
* Manga/YamiNoAegis:
--> '''Tate''': I will not kill, nor will I assist in anything leading to killing.
* Juvia of ''Manga/FairyTail'' admits to live by this philosophy when she fights Meredy, and she states that the other Fairy Tail members do the same. Ironically, Juvia was a former member of the rival guild Phantom Lord which members (at least most of them) didn't seem to hesitate killing their opponents. It's unknown if Juvia also had her no-killing moral code when she was a Phantom Lord member, of if she undertook it after her HeelFaceTurn. Interestingly, another Fairy Tail member, Gajeel, also pulled a HeelFaceTurn from being a Phantom Lord member, and when he was a villain he didn't shy away from trying to kill the heroine Lucy. He has still shown to be quite AxCrazy even after turning good, so it's definitely not sure that he refuses to kill his opponents even though he might not do it in cold blood.
* In ''Anime/GingaDensetsuWeed'', Weed (the [[KidHero Pup Hero]]) strongly believes in releasing enemies after they had enough. Doesn't stop him from killing a wild boar that threatens his pack, though.
* Despite him beating his enemies to a pulp, Issei the protagonist of ''LightNovel/HighSchoolDxD'' hasn't killed anybody at all. Not even {{Mooks}}!
* ''Manga/CodeBreaker'' has the main character [[ActionGirl Sakura]] who goes to great lengths to prevent Rei and others from killing, as she believes all life is precious. However after the Re:Code arc, expect her personality to [[{{Flanderization}} be centered around this]].
* This is the key point of contention between [[HeroesRUs Ryozanpaku]] and [[NebulousEvilOrganization Yami]] in ''Manga/KenichiTheMightiestDisciple''. Yami's followers believe in upholding the "Satsu-jinken" (killing fist) philosophy, which they feel is the most original (and therefore most authentic) interpretation of all martial arts. On the other hand, Ryozanpaku's martial artists uphold the "Katsu-jinken" (merciful fist) philosophy, as they believe there is no longer any need for killing-based martial art techniques in the modern world.
* In ''Anime/EurekaSeven'', both Renton and Eureka have to stop killing humans after Renton realizes what he has been doing to the KLF pilots, and when Eureka realizes the value of human life.
** In the TV sequel ''Anime/EurekaSevenAO'', Eureka did not attack the Scub Coral despite her antagonizing it, to honor her husband Renton's wish not to kill her own kin.
* In [[http://www.animenewsnetwork.com/answerman/2012-12-28 one of his Answerman columns]], Website/AnimeNewsNetwork contributor Brian Hanson deals with this trope as it applies to fiction in general, and {{Shonen}} anime in particular:
-->"In the case of ''Manga/{{Naruto}}'' and ''Anime/DragonBallZ'', the reason you don't see any of the main characters take a life is pretty much the same reason most of the villains in Creator/{{Disney}} movies [[DisneyVillainDeath fall to their death offscreen]], rather than killed triumphantly by the heroes. It's because we want our protagonists to remain pure. Even if it were justified, we'd rather not have blood on the hands of our favorite, pure-hearted characters. Given that Goku and Naruto themselves function as, essentially, the moral compass of their respective worlds, it makes narrative and thematic sense for them to avoid any sort of bloodshed, no matter how dicey things get."
* In ''LightNovel/ACertainMagicalIndex'', Touma Kamijou is noted for his ability to defeat bad guys and solve problems without killing anybody, and he'll even save his enemies' lives. In the light novel version, he came close to crossing the line when Aureolus Dummy turned a girl into a gold statue and then melted her. In a rage, Touma beat him half to death, then was horrified and allowed him to leave.
* Dr. Orson from ''Manga/ACruelGodReigns'' stresses this to Jeremy while he is counseling him before his death. He tells him that killing will only succeed in harming his own soul in the end. Subverted when Jeremy, while still considering this, commits VehicularSabotage.
* ''Franchise/LupinIII'' [[ZigzaggedTrope zig-zags this trope.]]
** In the early comics, Lupin didn't have a problem killing. Even the early Anime has it happening in cruel or horrifying ways. Most adaptations, however, are LighterAndSofter, so Lupin and gang distance themselves from their enemies with this view.
** This trope is especially noted towards Zenigata; both characters have mentioned that they have an understood "gentlemen's agreement" that neither will attempt to kill the other, and have saved each other's life (several times, in fact).
* [[ActionGirl Balsa]] from ''Anime/SeireiNoMoribito'' refuses to take a life, no matter the circumstances.
* Akane Tsunemori in ''Anime/PsychoPass'' refuses to kill criminals, unlike [[AntiHero the rest of her team]]. This is made especially clear in the second season premiere, when the MadBomber they are chasing has a Crime Coefficient of 302, which just barely puts him in the 300+ threshold of being [[LudicrousGibs vaporized]] by the Dominator's Eliminator Mode, but she opts not to shoot him and uses her negotiation skills to talk him down to 299 and bring him in nonlethally. Something similar happened in the first season premiere, but the big difference is in that case it was a victim she was talking to, not the instigator of the crime. However, she has limits to her compassion: when that same bomber committed another crime and this time killed over a dozen people with a bomb, she outright told him any sympathetic words she'd told him were now meaningless and she was ready to give the order to execute him had Inspector Aoyanagi not shot him first.
** She also refused to kill the respective BigBad of each season, but in those cases, she also had practical reasons to do so besides her own morals: [[spoiler: in Makishima's case, she had a chance to kill him at Nona Tower, but was under very clear orders from Sibyl to bring him in alive, and her sense of justice prevailed. Later, she cut a deal with Sibyl to bring Makishima in alive in exchange for Sibyl agreeing to let Kougami go free, which failed when Kougami killed him. In the second season, she becomes suspicious of the fact that the Sibyl System really, ''really'' [[RevealingCoverup wants Kamui dead at all costs]] without an explanation, and prioritizes bringing him in alive to find out why he's such a threat to the System. Even when Sibyl frames Kamui for the murder of her grandmother, she's perceptive enough to realize he couldn't have killed her and won't take the bait.]]
[[/folder]]

[[folder: Comic Books]]
* Franchise/{{Superman}} has taken a solemn vow ''never'' to kill. It's strongly implied - and outright {{invoked|Trope}} in ''ComicBook/WhateverHappenedToTheManOfTomorrow'' - that he believes that he should give up being Superman if he takes one. (He cannot kill himself, since his oath applies to himself as well. This was shown in a number of Bronze Age stories, including one where he is caught in a hallucination that supposedly shows the future and realizes that since it shows him killing himself, it must be false.)
-->'''Superman:''' I broke my oath. I killed him. Nobody has the right to kill. Not Mxyzptlk... not you... not Superman. '''Especially''' not Superman.
** A ComicBook/PostCrisis Franchise/{{Superman}} story had the hero face such a situation when an abusive husband, whom Supes gave a deserved thrashing, later murdered his wife. Superman later caught him secretly viewing her funeral and was sorely tempted to kill him right there and then. However, the relatives of both husband and wife began to plead for Superman to spare him and kill him respectively. Superman, holding the murderer while this argument is raging, painfully realized that he was in no position to make such monumental decisions and decided to simply hand the criminal to the police so the justice system can handle the matter.
** Another Superman story, "What's So Funny 'Bout Truth, Justice, and the American Way?" famously had him forced to deal with the arrival of "The Elite" (a [[AlternateCompanyEquivalent thinly-veiled copy]] of ComicBook/TheAuthority), superheroes with absolutely no qualms about killing villains. Over the course of the issue, he watched them become more and more popular, despite their excessive use of force. In the end, he challenged them to a fight - and proceeded (after giving them a HopeSpot) to subdue them more or less harmlessly. Though it sure dang LOOKED like he killed them, until he revealed that he used painful-looking non-lethal techniques. The story showed not only why does Superman not kill, but just how downright ''scary'' he would be if he did. The story eventually got an AdaptationExpansion into the made for DVD movie ''WesternAnimation/SupermanVsTheElite''.
** And another Superman story had him actually killing (well, executing) three Kryptonians on an alternate Earth who had annihilated all life on the planet. Despite the circumstances which almost anyone else would deem it both just and necessary--as they had committed the act of planetary murder, threatened to find an way to Superman's universe and do it again, and were stronger than he was--the act haunted him for years. After he did it, he even developed a split personality and then exiled himself from Earth after he got that under control.
** This trope is somewhat justified in another story where Superman explains to the Ultramarines, a team of superheroes known for their use of lethal force, after the Justice League has pulled them out of a situation they were unable to handle, that their "'no-nonsense' solutions [[BackFromTheDead just don't hold water]] in a [[CrossoverCosmology complex]] [[FantasyKitchenSink world]] of [[EverythingsBetterWithMonkeys jet-powered apes]] and TimeTravel," as death apparently held less barriers for them, and in fact was more merciful, than some of the extreme incarceration punishments the League had to devise.
** Superman has shown to be one of the most extreme examples of never killing. In one case he saved ComicBook/{{Darkseid}}'s life (Darkseid helped him stop the threat that put him near death, granted, but come on, it's freaking ''Darkseid'') and in another instance, he was trapped in a dimension where he was forced to go to war with demons for a thousand years, but still refused to kill them. He even initially objected to Franchise/WonderWoman killing them, but didn't have an answer when she asked him what she was supposed to do.
** Though it's often overlooked, during his final fight with Doomsday at the end of "ComicBook/TheDeathOfSuperman" storyline, he was trying to kill him. If he hadn't, Doomsday likely would've destroyed Metropolis and everyone in it. It probably helps that Doomsday's mind was read a couple of times in the story, and was revealed to be nothing but rage and bloodlust. This was followed up in ''Hunter Prey'', as Superman, after finding out that Doomsday was now far more powerful than himself, and constantly growing in might, he could come up with no other available options than letting Waverider exile the beast to the end of the universe, to let entropy consume it. Doomsday was later rescued by Brainiac, keeps coming back after being killed, and heals all other injuries instantly, so breaking his neck has the same effect as knocking a regular villain out, which, in combination with being more than Superman can handle upfront, is the reason why he can be the exception.
** ''ComicBook/KingdomCome'' revolved around the fact Superman abandoned humanity when he realized the public approved Magog's murder of SelfDemonstrating/TheJoker.
** In the pre-Crisis mini-series ''Phantom Zone'' Superman confronts General Zod, who laughs that Kal-El won't kill him. He's right. To quote: "I can't take your life, much as I'm tempted. But my code doesn't say a '''''damn''''' thing about not battering you to within an inch of it, ''murderer!''" Once Zod is out cold for a long, long time, Superman, still holding him by the tunic, thinks "And there are times I've considered chucking that code entirely."
** Played with in the ''Comicbook/LegionOfSuperHeroes'' story where the Legion decided whether to expel Star Boy for killing. Superman voted to not expel him. The reason? Because it's easy for him, Superman, to have a code against killing when there aren't a lot of things that can hurt him, but other people may have different circumstances than him and he has no right to hold them to his code.
** Emphasizing Superman's adherence to his code is this: in the few official {{crossover}} series that exist, Superman has even refused to kill ''[[Franchise/{{Alien}} Xenomorphs]]''! For context, xenomorphs are a highly aggressive species of alien predators with no higher reasoning than basic animal instincts and a parasitic reproductive cycle, which are capable of causing ''planet-scale extinction events'' thanks to their voracious and insatiable need for living victims as food and hosts for their young. Even ''Batman'', himself a noted devotee of this rule, is willing to forgo it when xenomorphs are involved, and in the Superman/Batman/Aliens crossover (yes, this exists)), actually calls Superman out on his willingness to spare such dangerous animals.
** In ''ComicBook/OurWorldsAtWar'' he helps kill both Imperiex and Brainiac 13 by sending them both back in time to the Big Bang; in ''ComicBook/FinalCrisis'', he is the one who finishes off Darkseid. In general his code is based on the fact that he is far more powerful than most of the villains he comes across and if he is capable of defeating them without resorting to violence, he will; on the flip-side, if you are an enemy who is as strong or stronger and you are sufficiently ruthless or dangerous enough that death is the only thing that will stop you...then yes, Superman ''will'' kill you. Helps if [[WhatMeasureIsANonHuman you aren't human, too.]]
** There were at least two [[UsefulNotes/TheBronzeAgeOfComicBooks Bronze Age]] stories in which criminals tricked Superman into believing he had accidentally killed someone, so that he would hang up his cape and stop fighting crime (in one, they tricked him into thinking he had accidentally killed Lana!).
** This was the central point of the Bronze Age text novel [[Literature/MiracleMonday Superman: Miracle Monday]]. A demon called C.W. Saturn possesses a woman and causes havok, trying to tempt Superman into stopping him by [[MercyKill killing her physical form]]. [[spoiler:If it had succeeded, Superman's soul would have been damned. Superman refuses, of course, and defeats the demon by constantly reversing its mischief until its time on Earth runs out.]]
* The ComicBook/PostCrisis version of Franchise/WonderWoman has trained as a classical Greek warrior with a fighting practicality of that time. That means while she is willing to control herself in combat when possible, when she decides that lethal force is necessary, she will use it without any regrets as seen when she beheaded the demigod Deimos in order to help her friends in peril.
** In a {{crossover}} series, Franchise/WonderWoman cold-bloodedly executed Maxwell Lord by breaking his neck. Although some other heroes have accepted the justification (Lord had telepathic control over Superman, had killed ComicBook/BlueBeetle, and was at the heart of a planet-wide conspiracy), she was wanted for murder by some authorities as the act was broadcast. Might be noted that she used the Lasso of Truth on Lord and he told her she would ''have'' to kill him if she wanted to stop him, so as far as Lord himself thought at least, killing him was the only real choice.
** Her killing of Von Bach in ''ComicBook/KingdomCome'' was the climax of her HeroicBreakdown during the miniseries, and earned her a WhatTheHellHero from Franchise/{{Batman}}.
*** This marked a major turning point in the depiction of her character. Traditionally, much of the point of Wonder Woman was that she was the most ''compassionate'' of the big heroes, sent into Man's World to teach us a better way. [[CompletelyMissingThePoint The entire point of depicting her use of lethal force in Kingdom Come's dystopian future is that it was violently out of character for her.]] However, it became such an iconic image that now she has, ironically, become known as the only member of the Big Three who ''will'' kill.
* In the long running independent superhero comic book, ''[[{{Comicbook/Nexus}} Nexus]]'', the titular superhero kills as the very reason of his career; he periodically has agonizing dreams of the crimes of murderers that will drive him insane unless he eliminates the cause by going out to kill the criminals and he has the power to get through nearly any defense to do so.
* In recent years comics have tended towards a greater degree of [[SlidingScaleOfIdealismVersusCynicism cynicism]], or been more willing to engage with the ambiguities of this rule, with the result that most heroes have ended up killing at least once.
* ''Franchise/{{Batman}}'' is the poster boy for this trope. In fact, it's been heavily implied that his almost psychotic compulsion to never kill is the only thing keeping him from being one of the psychopaths he regularly fights - he has outright stated that he fears if he started, he would never stop. Famously, Batman [[EarlyInstallmentWeirdness was willing to kill]] in the first year of his existence. As early as ''Batman'' #4 in 1940, he was declaring "We never kill with weapons of any kind."
** ''ComicBook/FinalCrisis'' has [[IncrediblyLamePun finally]] shown us the only person so evil and dangerous Batman was willing to kill him: [[spoiler: Darkseid. Which just makes the Superman example above even funnier]]. By the time Batman kills [[spoiler: Darkseid]] the villain has taken several [[TookALevelInBadass levels in badass]], and [[spoiler: was destroying the entire universe ''just by existing''. Whereas Superman saved an alien warlord, but this point it's one life against ''all of time and space'']].
** The Creator/TimBurton Batman movies disregard this entirely, with Batman frequently killing both henchmen and the central villains. TheDarkKnightSaga Batman refuses to kill anyone, but he is generally [[HighAltitudeInterrogation more than happy to come scarily close to frighten someone, without actually crossing the line.]] This is demonstrated best during ''Film/TheDarkKnight''.
-->'''Salvatore Morone''': "From this height, the fall wouldn't kill me."
-->'''Batman''': "I'm counting on it."
** ''Comicbook/{{Flashpoint}}'' Batman [[spoiler: aka Thomas Wayne]] dispenses with this altogether and shows himself to be an exceptionally violent and uncompromising psychopath who has killed off a good portion of the villains in that timeline and threatens to use lethal force all the time.
*** Similarly, his ''Earth 2'' counterpart is more than willing to kill, and it's what tips Lois Lane off that the batman in front of her ''isn't'' Bruce Wayne, since the ''Earth 2'' Lois was in on his SecretIdentity and was very close to him and his wife.
** In the {{Novelization}} of ''ComicBook/{{Knightfall}}'', Batman's use of violence is explored. A monk refuses to teach Batman some of the most secret fighting techniques because he won't foreswear violence. Lady Shiva teaches Batman to fight again, but is mildly offended and amused when Batman learns how to ''enjoy'' violence again, but won't cross the line into lethal violence. Bruce has a startled, depressing EurekaMoment when he realizes that he'd always ''loved'' the violence, despite what he told himself.
** Cassandra Cain[=/=][[ComicBook/{{Batgirl 2000}} Batgirl]] II had an even deeper aversion to killing as she could read human body language perfectly. After seeing death once she vowed to never see it again and tried to save a death row inmate to uphold that oath.
** This is so inherent to his character that it's called '[[TropeNamers the Batman rule]]' by other characters, specifically ComicBook/{{Batwoman}} and her father.
** Batman will often take this trope to extremes. Not only will he avoid killing his enemies, if his enemies are dying of natural causes or of a HoistByTheirOwnPetard situation, [[UpToEleven if he can, he'll save them]] even villains as bad as TheJoker.
** This is the basis of [[ComicBook/{{Azrael}} Jean-Paul Valley]]'s tenure as Batman during ''[[ComicBook/{{Knightfall}} Knightquest]]'' as he would be lost within the System and constantly battling between acting like Batman and acting like Azrael. It's only when he allows Abattoir to die is when everyone decides to shut him down.
** During [[https://www.youtube.com/watch?v=wAg2m5UlBYw a non-canon fight]] between Batman and {{Deadpool}}, Deadpool mocks that Batman can't beat him because he can't be killed. Batman snaps, "I'm ''counting'' on that." Cue Batmobile twin rocket launchers turning Deadpool into LudicrousGibs. After Bats leaves with Catwoman, Deadpool's head is mildly annoyed.
** In fact, Batman hates to see ''anyone'' die. It's the crux of ''ComicBook/KingdomCome'' when Superman tells him the one thing they both had in common was they saved people. Heck, in ''ComicBook/JLAAvengers'', while Plastic Man is amused by ThePunisher killing drug dealers in a firefight, Batman immediately goes to beat the everliving crap out of Frank, to ''save'' said dealers.
* The bylaws of the ''ComicBook/LegionOfSuperHeroes'' firmly forbid killing any sentient - unsurprising, since they were created during UsegulNotes/{{the Silver Age|OfComicBooks}}. The tradition has been retained throughout the Legion's various continuities; even in the DarkerAndEdgier ''Legion Lost'' limited series, Live Wire officially resigned from the Legion before performing a HeroicSacrifice to kill the Progenitor, an OmnicidalManiac with [[AGodAmI the power to control matter on a cosmic scale]], in order to allow his teammates to escape without the Progenitor following them back and taking over their universe.
** The Legion Constitution was once published in the comics, in its entirety. The section in question says that "[n]o Legionnaire shall take the life of any sapient being, save as a provable only alternative to the death of the Legionnaire, or the deaths of other sapient beings." The writers usually have the Legionnaires treat the question of lethal force more strictly than their constitution actually requires.
* {{Lampshade|Hanging}}d in ''ComicBook/{{Invincible}}''. After the [[SuperTeam JLA-analogue]] repels the same AlienInvasion for a second time (by destroying the devices that allow them to safely exist in our universe), Invincible, as the NaiveNewcomer, wonders at the wisdom of just letting them go again:
-->'''Robot''': Keeping them here would be a death sentence. Hopefully they've learned their lesson.
-->'''Invincible''': Right... and '''I'm''' supposed to be the new guy.
-->'''Robot''': It is not mathematically inconceivable that at some point we encounter an adversary that realizes the error of their ways and gives up their plans for revenge.
-->'''Invincible''': I hope you're right.
* In the Creator/{{Wildstorm}} imprint, in one issue of ''ComicBook/TheAuthority'', it was mentioned that an alternate earth was essentially destroyed when the Hero refused to kill their enemies no matter what, and the villains killed every single one of them. They attacked the Authority's Earth, and were quickly killed, much to their surprise, saying "Superheroes don't kill". Unfortunately for them, The Authority did. This universe in general, and ''The Authority'' especially, fall on the cynical side.
* In ''ComicBook/AstroCity'', the Street Angel, a Batman-like vigilante who had recently become DarkerAndEdgier but who still refused to kill, receives a nice bit of smack-talk from murderous {{antihero}}ine Black Velvet. She notes that, although he still claims that he never kills, [[TechnicalPacifist he leaves an awful lot of people with severe internal injuries]] without actually checking to see whether they survive or receive medical attention. (After she says this, a BeatPanel follows as this sinks in...)
* ''Comicbook/{{Daredevil}}'' used to have a typical view of killing, claiming that it wasn't his place to pass judgment. During Creator/FrankMiller's run, which redefined the character, Daredevil eventually went against his principles when he tried to kill his archenemy Bullseye. He's killed people several times, and he hasn't tormented himself for issues on end because of it, perhaps the only "regular" superhero who can make this claim.
** However, despite the occasional team up he is frequently at odds with ThePunisher for his blatant disregard of the no-kill rule, to the point where the latter might qualify as a members of Daredevil's RoguesGallery. Though their enmity has softened somewhat ever since Punisher rescued Matt from prison and helped him keep his secret identity, Daredevil was probably the hero most devoted to locking Frank Castle up, even more than ComicBook/SpiderMan who hardly ever tried to capture him. Murdock was known to organize hero teams for the sole purpose of hunting The Punisher down.
*** The key word here being "blatant." Daredevil has killed when the situation called for it. And when the situation has called for it, he has hated but not regretted doing it. That said, he does not endorse wholesale murder as the answer to his, or anyone else's, problems.
** [[spoiler: Well and truly averted after he finally killed Bullseye.]]
* ComicBook/BlackPanther is not averse to killing, though he usually tries to use non-lethal means if at all possible. During his run as the protector of Hell's Kitchen, he notably told a thug that as a warrior first and foremost, he did not share Daredevil's no-kill rule.
** And in the first arc of the third ''ComicBook/NewAvengers'' series, he tells [[ComicBook/SubMariner Namor]] that once their mission is over, he's going to kill him for the innocent Wakandans that were drowned during ''ComicBook/AvengersVsXMen''.
* In ''ComicBook/TheAvengers'', there is (was?) a very strong policy against killing, to the point that one of their mottoes was "Avengers don't kill." This has been brought to attention several times, with ComicBook/{{Hawkeye}} almost getting separated from his wife because he heard that she allowed her rapist to fall to his death.
** Their later divorce was specifically built on the tension caused by this incident. Notably, however, all the Avengers who heard ''Mockingbird's'' side of the story (Hawkeye heard about it from the ghost of the dead man, who significantly downplayed his actions) sympathized with her, because her circumstances were considerably different from that of their usual fights.
** These days, they are a little more flexible about this rule.
** Specifically, it's a bit of CharacterizationMarchesOn. After ComicBook/ScarletWitch killed Hawkeye, [[ComicBook/AntMan Ant-Man]] and TheVision during ''ComicBook/AvengersDisassembled'', ComicBook/IronMan came to the conclusion that it was unethical and dangerous to completely take killing off the table. He asked ComicBook/{{Wolverine}} to join the Avengers precisely because he wanted a hero who wouldn't hesitate to use lethal force if a situation ever called for it.
** This was continued in ''SecretAvengers''. In one instance, Beast was forced to kill a group of terrorists in order to save the populations of two large cities. He was understandably upset by this, and ComicBook/CaptainAmerica comforted him by telling him not to dwell on the few lives he'd taken, but the millions he'd saved.
* ComicBook/SpiderMan is also strongly against killing anyone. He's the most pacifistic person of the Marvel Heroes due to his kindness and nobility, valuing every life and taking responsibility for every action. He takes this to a massive extreme after [[spoiler:the Spider-Slayer murders J. Jonah Jameson's wife]] and, haunted by it all, declares no more lives will be lost if he's around.
** In ''ComicBook/SpiderManNoir'', Peter carries a revolver in his masked identity, and uses it to [[spoiler: kill the Vulture when he threatens Aunt May. The fact May is as horrified by him as the Vulture is what convinces him to adopt his mainstream counterpart's morals]].
** In ''[[Comicbook/SuperiorSpiderMan Superior Spider-Man]]'', Massacre is executed by the new Spider-Man (Otto Octavius) after going on a bloody killing spree. Wolverine defends Spider-Man's actions by noting that Massacre was a particularly vile and depraved villain, and that most of the Avengers have used deadly force at one point or another.
* In ''ComicBook/XMen,'' the rule against killing is partially due to the usual reasons, and partially due to human/mutant relations. Mutants have a hard enough time ''without'' ComicBook/{{Wolverine}} carving people up on the six o'clock news, so you'd better stifle any DarkerAndEdgier tendencies, ''especially'' while wearing an X symbol. However, it's not as absolute as it is with Batman or Superman, as individual members can fall anywhere from TheCape to NinetiesAntiHero, and most X-teams will defend themselves or others lethally if it's [[IDidWhatIHadToDo the only way]]. A few of their main villains also have JokerImmunity.
** In general, Xavier has a personal no-killing policy, and he does his best to enforce it on teams he leads. But there have been many different leaders of the X-Men over the years, and many teams affiliated with them but not actually accepting Xavier's authority.
** In one issue, Cyclops explicitly refutes this trope with regard to villains over Storm's objections when they're looking for a villain who may have perished in a fight with the team; he states that he doesn't take killing lightly, but at the same time isn't going to waste any tears over someone who poses a clear risk to his team and students and has no compunction about attacking and killing them.
** Nineties anti-hero Comicbook/{{Cable}} (an amazingly powerful telekinetic infected by a nano-technological virus who used huge guns ... no, really) had no qualms about killing and invariably racked up a huge body county every issue. Always without any ramifications. And in his most recent shared series, he came across as the good partner. The other guy was {{Deadpool}}.
* Invoked to an almost headache-inducing degree in the early 2000s run of ''JusticeSocietyOfAmerica''. BlackAdam, having gotten utterly fed up with villains who don't give a damn about the lives of people being allowed to go free again and again, gathers up a small crew of like-minded people and goes off to smash the brutally dictatorial regime that's set itself up in his home country. Even though one (''one'') JSA member acknowledges that they and the US government had turned a blind eye to the fact that these people had been conducting murder sprees and enslaving children, the ''entire team'' nonetheless goes after Adam's crew for taking them out. And then when Hawkman's methods for dealing with ''Black Adam's'' allies proves too brutal for their taste, they turn on ''him''. All in about five issues.
* The Franchise/GreenLantern Corps ''used'' to follow this policy. The Guardians revoked it in order to defeat the {{Sinestro}} Corps. [[spoiler:[[XanatosGambit Apparently this was Sinestro's goal all along.]] Whether the Sinestros won or lost, a more lethal and fearsome Corps would be policing the cosmos.]] Part of the writers' reasoning was that real-life police are permitted to shoot to kill; SpacePolice shouldn't be any different.
** This is actually one of the few times both sides are given fair consideration. Some Green Lanterns are against it, some are all for it, but neither side is presented as wrong and the ones against killing can't deny that being able to kill was the main reason they won the war. (Though needless murder is right out.)
** There was a subversion in the case of NinetiesAntiHero Jack Chance. When he discovered his GreenLanternRing would not let him use lethal force, [[LoopholeAbuse he adapted and started using a revolver to deliver the killing blow.]] The only reason the Guardians didn't throw him out was because nothing less had worked on his CrapsackWorld.
* The ''Comicbook/SonicTheHedgehog'' comic has something like this: in one issue Dr. Robotnik, [[spoiler:still insane after the events of issue 200, is locked up in New Mobotropolis. A character asks Sonic why he's showing mercy to Robotnik. Sonic admits he doesn't know for sure, and guesses he moves too fast to get hung up on revenge. The character isn't sure if Sonic has a Zen state of mind or is foolish, but he's impressed either way.]]
** In issue 225 Robotnik [[spoiler:mocks Sally for showing mercy on all the times she could've finished him, as doing so allowed him to stay a threat. A few pages later, he seemingly killed her, then reset the Universe.]]
* During ComicBook/DarkReign the ComicBook/{{Thunderbolts}} team observed that, despite being Osborn's hit squad, they almost never killed anybody. In fact they completed one assassination without taking any lives.
* Used for great dramatic effect in ''ComicBook/ElfQuest''. The main tribe of the story, the Wolfriders, have one simple rule: elves don't kill elves. It's a concept so ingrained in their culture, killing others of their kind would not even occur to them. Until one elf from a different tribe, Kureel from the Gliders, ends up kidnapping a young Wolfrider and threatens to kill him. The boy's father (the tribe's archer) shoots and kills Kureel. He goes into a complete HeroicBSOD until he's finally able to ask Kureel's spirit for forgiveness many months later. As it was, since Kureel's spirit was at peace and barely remembered the circumstances of his demise anyway, he granted that forgiveness without hesitation
** Interestingly, at the very start of the series, the Wolfriders seem to treat death ''much'' more casually, briefly considering killing Rayek because he looks at them funny. This is, however, shortly after the humans burnt down their home and the trolls betrayed them and left them to die in the desert, and while they were still figuring out what to make of these strange new elves who walked around in broad daylight, had huts, and actually ''cooked'' their meat just like their old human enemies did. (It's telling that the Wolfriders decided to 'introduce' themselves to the Sun Village by raiding it for food rather than just walking up and saying hello. Thankfully for both sides, that didn't last long.)
** Also interestingly, in the very early days of the Wolfrider tribe, there were many elves born with wolf-blood and just as many wolves born with elf-blood (it's not as icky as it sounds - the first elves were shapeshifters lost on a low-magic planet. Mating with the local fauna was their way of bonding with the new land). Timmorn, the first Chief and first mix between elf and wolf, took on the task of deciding what was elf, what was wolf, and what should just be killed instantly.
** Two-Spear didn't have too many qualms either about killing his own daughter. But (a) Two-Spear tried to be more wolf than elf, using the pack's way of life as an excuse to act violently insane, and (b) the story in which he thinks he's killed his daughter was a case of RunningTheAsylum anyway.
* Obviously, ComicBook/ThePunisher [[AvertedTrope has no business with the standard version of this]]. However, [[WouldNotShootAGoodGuy he will absolutely under no circumstances ever kill someone who isn't a criminal or otherwise corrupt]]. [[WouldNotShootACivilian He'll go out of his way to prevent bystander casualties]] and will even let a bad guy slip if he has to. (DependingOnTheWriter. At least one issue has him willingly allow a woman to be killed in order to stop a criminal who is banking on his "Doesn't allow innocents to be harmed" schtick.)
* With the exceptions of truly mindless incarnations of the character, the ComicBook/IncredibleHulk rarely kills anyone intentionally. Most deaths caused by his rampages are accidental and the result of property damage, that--to be perfectly fair-- could result from most superhero battles (admittedly, the Hulk tends to cause more damage than most superheroes). Even then, deaths are fairly rare. In one issue, where Bruce Banner admits to murdering his abusive father and making it look like an accident while defending himself, he stated that as the Hulk, [[NoEndorHolocaust he had leveled entire cities without killing a single person]]. All of this being said, it isn't clear just how much of this is intentional and how much is coincidental; in some cases the Hulk clearly intends to kill an enemy, with them happening to meet a KarmicDeath during the course of the battle.
* In ''ComicBook/{{Empowered}}'', this is played utterly straight with the title character; even her most powerful energy blasts have never been seen to do worse than knock someone out cold. The rest of the cast ([[spoiler:including, from the look of things, her costume]]) averts it, especially Thugboy. [[spoiler:In volume 6, she does leave Deathmonger to be disintegrated by a nuclear blast... but he's not only an enslaver of the walking dead, but a walking dead man himself.]]
* ''ComicBook/BirdsOfPrey'' member ComicBook/{{Huntress}} had no time for this early in her vigilante career. She's getting better, but she still doesn't seem to have too much of a problem with killing criminals. It's the main reason Franchise/{{Batman}} doesn't trust her. Oracle, being more forgiving and willing to offer second chances, does trust her. Oracle does, however, use this excuse to treat her like crap.
* ComicBook/GreenArrow is a big believer in this. It's why he uses so many trick arrows, like the infamous boxing glove arrow, instead of actual arrows. The downward spiral that culminated in his first death started the night he actually killed someone. [[spoiler: He made an exception for Prometheus after the latter attacked Star City with a KillSat and killed thousands, including his granddaughter Lian Harper.]]
** Seriously averted during Mike Grell's run, where Green Arrow began using lethal force regularly after killing a man who was torturing Black Canary. The series flip flopped on how he felt about killing, sometimes doing it casually and other times feeling remorseful about it. Once his series ended, the events and characterization have been ignored.
* Enforced in ''ComicBook/QuantumAndWoody'' by Quantum's heroic idealism. This proves problematic when the duo attacks Terrence Magnum's private mercenary army and Quantum has loaded Woody's rifle with ''rubber bullets''.
* In one issue of ''ComicBook/AlphaFlight'', the writer says [[{{Anvilicious}} "Some armchair moralists would hold superheroes to an impossible standard, requiring them to routinely face opponents who use lethal force while denying themselves the same option."]] This punctuated a series of panels in which the members of the team agree, reluctantly and with much debate, that the particular foe they're facing cannot be contained, cannot be controlled, and cannot be made anything remotely resembling safe. You can guess what comes next. Surprisingly, this did not mark a StartOfDarkness for the title.
* In Antarctic Press' ''ComicBook/GoldDigger'', the giant superheroine Crush is adamant about this - mainly because, during a brief period during which she was being blackmailed by a supervillain, she killed a bunch of gang members... and, coincidentally, an undercover cop.
* ComicBook/MoonKnight is a strange case. Being Batman wearing white and an obsession with Egyptian moon gods of vengeance, he has a disdain towards killing. However, it's not so much he doesn't want to be like the people he fights, it's that he is ''extremely'' tempted, to the point of addiction, to killing, and wants to fight it. Doesn't stop him from torture, maiming, and cutting off a guy's face ''[[CrossingTheLineTwice and wearing it]]'' for the sake of the moment.
* The Franchise/TeenageMutantNinjaTurtles, being ninja, were pretty much trained to kill from their first appearance in order to avenge Splinter's owner via his death from The Shredder. It varies from incarnation to incarnation with some versions vowing never to kill, but for the ones that do it's made apparent that none of them really relish having to kill anyone period, but if it comes down to survival or saving someone they will take that step.
* Discussed in Issue 9 of ''The Shade'' (2011). The Shade is about to kill a villain before he brings up this trope. The Shade outright denies being something so "average". The villain then talks to Silverfin, a friend of The Shade's and a true hero. Silverfin then responds that, as a hero, he only fights for what he ''perceives'' as good, citing no superhero rulebook. And if letting this villain die is a good thing, then he'll let it happen.
* Subverted in ''ComicBook/PrinceOfPersiaTheGraphicNovel''. Guiv subdues a lion which attacks him in the mountains. Kneeling over the lion, he lifts his sword, then has a thought and says, "No one gave me the power to take life." As he walks away, the lion gets up and charges at him, and he quickly turns and slashes it to death.
-->'''[[IntellectualAnimal Turul]]''': No one gave you the power to ''spare'' life, [[VerbalTic yaaahr]].
* This attitude causes some trouble for Batman in ''Comicbook/{{The Ultimate Riddle}}'', as he isn't willing to murder those who are trying to kill him. This is contrasted against the more [[{{Combat Pragmatist}} pragmatic]] Dredd, who has no moral qualms with lawful killing, though isn't pleased to be doing so for someone else's amusement.
* Subverted in ''ComicBook/LuckyLuke: The Tenderfoot''. The titular character, Waldo Badminton, challenges the BigBad to a TenPacesAndTurn duel. The latter panics, still manages to shoot first but misses, then [[VillainsWantMercy begs]] a [[StiffUpperLip stoic]] Waldo for mercy, offering him his estates and promising to never return; Waldo accepts. Whem Lucky Luke later asks him why he didn't shoot, Waldo reveals that he couldn't because the shot had hit him in the arm.
* Mocked by Hit-Girl in ''Comicbook/KickAss'':
-->'''Kick-Ass''': "No way. I'm not going to kill anybody. I'm supposed to be a fucking superhero."
-->'''Hit-Girl''': "Oh, kiss my ass. What is this, [[UsefulNotes/TheSilverAgeOfComicBooks the Silver Age]]? I'm afraid we forgot our magic fucking hypno-ring that turns bad guys into good guys."
* In ''ComicBook/{{Convergence}}'', our heroes from the mainstream universes keep running with this, incapacitating those they're forced to fight with and getting them to join them in their dome in some capacity.
[[/folder]]

[[folder: Fan Works]]
* In the Justice League/Naruto crossover [[FanFic/ConnectingTheDots "Connecting the Dots"]], the superheroes have a very hard time getting the ninjas (who are essentially underage soldiers) to understand this concept.
** One scene that stands out is where Robin and Cyborg are for this trope, Neji and Sakura are against and Naruto as devil's advocate after Neji killed Dr.Light. Just a taste of that talk:
--> '''Robin:''' "You killed him."
--> '''Neji:''' "Yes?"
--> '''Robin:''' "We don't...you weren't supposed to do that?"
--> '''Neji:''' "He was required for interrogation then? My apologies. I assumed termination was the objective"
--> '''Robin:''' "Termination is NEVER the objective! Not with us! We don't kill!"
--> '''Neji:''' (puzzled)"But the fight necessitated the need for lethal action. Cyborg (*points at him*) knocked him off a 10 story building with intent to kill."
--> '''Cyborg:''' "Well yeah, but… Dude, we knock people off buildings all the time! They just never actually fall, they always catch themselves!"
--> '''Neji:''' "So it was a distractionary measure? But I thought you didn't know he had that jetpack. And Beast Boy destroyed it shortly after, he could have died from either of those falls."
--> '''Cyborg:''' "Dude, the point is that a fall NEVER actually kills anyone."
--> '''Neji:''' "Yes they do. I've killed several people that way."
--> '''Robin:''' "The point is that Beast Boy and Cyborg didn't aim to kill him. You did."
--> '''Neji:''' "[[BluntYes Yes.]]"
--> '''Robin:''' "Look. In our line of work, you're not supposed to kill, understand? Not by accident, definitely not by intent. Regardless of the circumstances, you do NOT use lethal force."
--> '''Naruto,Neji and Sakura:''' "Why?"
--> '''Cyborg:''' "You… you just don't!"
** The argument ends with Cyborg and Robin saying that the villains normally get taken to prison. Naruto says "I get that. They get to live instead of executed. [[CardboardPrison As long as they can't escape from prison it's still good right?]] (Cyborg and Robin nervously look at each other) RIGHT?"
** Sakura actually questions Batman on this and points out the idiocy of it in some cases.
--> "If he (Joker) is so dangerous, why don't you kill him? Someone like that needs to be put down because it's clear he gets off on the killing and a monster like that doesn't need to exist."
* This is normally a point used in Harry Potter fanfiction when mocking a bashed Dumbledore, who he and his followers tend to view any sort of death as immoral and dark. For instance, in the story Harry Potter and the Curse's Cure, he is horrified by Hermione's fanfiction made uncle, Dan Granger's, killing of several death eaters with a gun (Despite the fact that they were there to kill and rape Hermione and her family). In the story The Harem War, he refers to Harry as dark when he kills Dolores Umbridge and two death eaters with a gun, despite the fact that the universe that Harem War exists in explains that Death Eaters have to kill in cold blood and rape to join, and the fact Dolores sent a squad of them into the innocent country that Harry ruled (of course, this Dumbledore is evil however).
* Not to say there aren't Fanon Harrys who believe in this rule, but it really depends on the writer and who they are dealing with. It is more acceptable among the fandom to mock a no kill policy when the people not being killed are Death Eaters as oppose to less utterly despicable characters.
* The four in ''Fanfic/WithStringsAttached'', being [[ActualPacifist Actual Pacifists]], are very much committed to this stance, sometimes to the point of having to get really creative to solve a problem because the opponent's death, or even the opponent's ass-whooping, is not an option. The irony is that collectively they have been gifted with enough power to wipe out a city before breakfast.
** Though at least two of them were not averse to handing out a good nonlethal ass-kicking in revenge for heavy abuse (of themselves or their TrueCompanions) at the hands of some baddies.
* ''Fanfic/PlasmasFolly'''s interpretation of N fiercely opposes killing after having to witness the deaths of many of the injured Pokémon Ghetsis gave him to play with as a child. This becomes a bit of an issue when he realizes that putting the suffering Genesect [[MercyKill to death]] may be the best option.
* ''FanFic/JusticeLeagueOfEquestria'': Rainbow Dash[=/=]Franchise/{{Superm|an}}re strives for this. [[spoiler: That said, she comes ''very'' close to breaking that rule when ComicBook/{{Brainiac}} whacks her BerserkButton by almost killing her mother -- she unleashes a NoHoldsBarredBeatdown on him and is barely talked down by Thunderlane before she goes too far.]]
* Empath in ''Fanfic/EmpathTheLuckiestSmurf'' tries to adhere as best as he could the Smurf rule of honoring all life, which also includes no killing, but in the story "The Innocence Of A Smurf", he reveals that he had killed a Psyche during a training battle where killing is mandatory for all Psyches that undergo this training. That earns him a death sentence on the day that he and his fellow Smurfs must swim across the Pool of Souls to judge his innocence, as he ends up dying during his swim. Fortunately, he only suffers a DisneyDeath as the spirits of the pool judge that he didn't kill the Psyche out of malice and thus he deserved a second chance.
* In ''FanFic/MegaManDefenderOfTheHumanRace'', [=ProtoMan=] has a self-imposed policy to not kill. [[spoiler:He breaks this vow in episode 9]].
* In the multi-crossover ''[[https://www.fanfiction.net/s/6438802/1/A-Spark-of-Genius A Spark of Genius]]'', Green Lantern insists that Leviathan (secretly a [[Series/BuffyTheVampireSlayer Xander Harris]] who's been magically made into the grandson of [[Webcomic/GirlGenius Agatha Heterodyne]]) is nothing but a murderer after he killed a group of soldiers and mercenaries. Said soldiers and mercenaries invaded his country, killed several civilians, and kidnapped a young woman with the intent of raping her before turning her over to Lex Luthor for the miracle cure running through her veins. Superman even points out that by international law, killing them and invading their country is completely justified, especially since Leviathan isn't a superhero but the leader of a nation.
* In ''Fanfic/FrozenHearts'', Johan Jorgen, a pirate, albeit a [[JustLikeRobinHood nobler sort]], has this principle, which is why he is disturbed when [[spoiler:Hans]] admits to [[spoiler:trying to kill Elsa]].
[[/folder]]

[[folder:Films -- Animated]]
* One of the three "Genie Rules" stated by the Genie from ''Disney/{{Aladdin}}'' prohibits him from killing anyone.
** Subverted in ''Disney/AladdinTheReturnOfJafar'', Jafar doesn't have any real problem with the rule, since he can still invoke a {{fate worse than death}} in either case or cause circumstances that result in a person's death as long as he isn't the one directly pulling it off. A RunningGag in the movie is, after mentioning that Genies can't kill, someone says "You'd be surprised at what you can live through!"
* Manolo from ''WesternAnimation/TheBookOfLife'', is firmly opposed to the idea of killing the bulls he fights, even though it earns him the ridicule of his family and the townsfolk, sans Maria.
* Completely averted in ''WesternAnimation/TheIncredibles''. None of the Incredibles have any problem using deadly force in self-defense, and a lot of mooks die as a result.
* ''WesternAnimation/{{Megamind}}'' knew that Metro Man went by this rule, always sending him to jail. It was one of things that made their battles seem like a game to him. Unfortunately, when he created Titan to take Metro Man's place, he didn't anticipate Titan making his own rules.
* In the infamous flashback scene in ''WesternAnimation/BatmanBeyondReturnOfTheJoker'', the Joker plays a [[BerserkButton Berserk Organ]] with [[MoralEventHorizon/WesternAnimation what he did to Tim "Robin" Drake]]. Just seeing the boy made Bruce [[UnstoppableRage beyond pissed]]; hearing the Joker's tale about how it all happened... he really was tempted to "break him in two". The film implies he actually ''would have done it,'' [[spoiler: if Tim hadn't killed him first.]] Joker thinks otherwise.
-->'''Joker:''' "Oh Batman, if you had the guts for ''that'' kind of fun you would've done it years ago. I, on the other hand..." (proceeds to attack)
* Since Baymax of ''Disney/{{Big Hero 6}}'' was programmed to be a healthcare robot, he naturally has an aversion to injuring people, much less killing them. [[spoiler:Hiro gets around this by removing Baymax's original PersonalityChip so he could be ordered to kill Yokai. When Baymax later comes to his senses and realizes what Hiro did, he physically locks Hiro out from accessing his {{Personality Chip}}s to prevent Hiro from forcing him to kill again]].
[[/folder]]

[[folder:Films -- Live-Action]]
* The Creator/TimBurton[=/=]Creator/JoelSchumacher ''Film/{{Batman}}'' movies have been a bit more flexible with this trope than the comic book version, with Batman demonstrating that he's not especially concerned if his enemies end up dead on numerous occasions. The Creator/ChristopherNolan [[Film/TheDarkKnightSaga movies]], however, have been a bit closer to this trope, with Bruce Wayne's refusal to kill a key element of his motivation ("That's why it's so important. [[IfYouKillHimYouWillBeJustLikeHim It separates us from them]]."). However, in ''Batman Begins'', he informs [[spoiler:Ra's Al Ghul]] that "I won't kill you... but ''I don't have to save you''.", before flying off, leaving [[spoiler: Ra]]'s in a train car that soon after [[HoistByHisOwnPetard crashes and explodes]], [[NeverFoundTheBody presumably killing him]]. Anyone who knows [[spoiler:Ra]]'s from the comics knows it's a case of [[spoiler:ImmortalLifeIsCheap]], even if Batman doesn't.
** The Nolan Film [[JustifiedTrope Justifies]] this because the last time he saved [[spoiler:Ra]]'s he came back and continued his KnightTemplar plan [[UngratefulBastard despite that]]. It's even lampshaded:
-->'''Bruce:''' "I saved your life."
-->'''[[spoiler:Ra]]'s:''' "I warned you about compassion."
** In ''Film/BatmanReturns'', he gives a clown a bomb, then '''''smiles sadistically''''' as the guy is blown to pieces. He ''enjoys'' killing in Burton's films.
** By ''Film/TheDarkKnight'' his moral philosophy appears to have evolved somewhat, as towards the end [[spoiler:he goes out of his way to save SelfDemonstrating/TheJoker's life. On the other hand, the Joker ''was'' trying to drive Batman to murder, so this looked like the only way to beat him.]]
** He also has another justification besides personal philosophy: he's a HeroWithBadPublicity in the Nolan films, so he knows acting as judge, jury, and executioner isn't going to help his reputation.
** Another fact to consider is that Batman ''personally threw'' the Joker off the building. If he didn't catch the Joker, then he explicitly killed him. But with Ra's, Ra's willingly put himself on the train with the knowledge that Batman would try his absolute hardest to stop him. Ra's taught Batman everything he knows and remembers that one time that Bruce unintentionally burnt down an entire fortress to avoid killing. Ra's obviously understood the potential risk of going against Batman, and one could reasonably assume that Ra's would have some sort of way to escape. Nolanverse's Batman follows the could that he will never intentionally kill a person, but if the bad guy puts himself into a position where s/he will be killed by collateral damage in the act of Batman saving Gotham / the innocent, and there is no way to save them, then there is nothing that can be done. Ra's had no way of saving himself on the mountain; but, Bruce could save him, and so he did. On the train, Batman had reason to believe that Ra's could save himself, and the only choices were Batman and Gordon destroy the train, '''''or every living thing in Gotham dies.''''' The same exact problem comes up in Film/TheDarkKnightRises, when [[spoiler: the nuke will go off in less than ten minutes, the tanks are actively trying to kill Batman and Catwoman, they can't force the truck to go back to the generator, and all warning shots have failed to get the truck to stop. Either the truck and tanks are stopped with force, '''''or literally everything in Gotham is wiped off the face of the earth and the rest of the US gets hit by the fallout.''''']]
** In ''Film/TheDarkKnightRises'' Batman explicitly tells [[Comicbook/{{Catwoman}} Selina Kyle]] "No guns, no killing.". She is less than enamored with the idea, responding, "Where's the fun in that?!" [[spoiler:Selina later saves Bruce's life by shooting Bane dead right as he is about to kill the hero, and jokingly states that she doesn't feel too strongly about the whole no-kill thing.]]
*** Later in the film, [[spoiler:the GodzillaThreshold is crossed and Batman fires his weapons with lethal intent, when intimidation with them failed.]]
** This is in comparison to ''Film/BatmanTheMovie'' when he was trying to find a safe place to dispose of a bomb he refused to throw it where anybody could get hurt. Including at ducks. Later in the movie when he and Robin accidently kill some mooks they do mourn for them as they weren't expecting them to [[MakesSenseInContext combust]].
* In ''Film/ManOfSteel'', Superman is placed in an impossible situation where, [[spoiler:General Zod, enraged beyond reason, has sworn he will ''never stop killing'' humans in an effort to hurt Kal-El for preventing the rebirth of Krypton. There is no super prison, no gateway left to the PhantomZone - just Kal, Zod, and a family of four about to be incinerated by Zod's rampage...so he ''breaks Zod's neck''.]] This not an action he undertakes lightly however, as the following scene shows.
** WordOfGod says that in the ''Man of Steel'' continuity, [[spoiler:this incident is ''why'' Superman swears never to kill anyone: he knows first-hand what a terrible, traumatic thing it is to take a life.]]
* ''Film/ButchCassidyAndTheSundanceKid''. Butch Cassidy, the tough, notorious, wildly-successful, train-looting, bank-robbing, gun-waving, {{badass}} outlaw, when faced with the prospect of a shootout, lamely admits to the Sundance Kid that he had never killed a man in his life. It's almost painful to hear Butch pleading with the bandits to go away so that he won't have to defend himself.
** Ironically, this is just after the two of them have quit their criminal lives for a legit job.
* In ''Film/WarriorsOfVirtue'', the Warriors cannot kill. In fact, when Ryan arrives, he learns that their leader, Yun, is in the middle of a HeroicBSOD because he accidentally broke that code in the heat of battle. [[spoiler:The fact that the soldier he killed was actually Elysia's ''brother'' probably didn't help his mindset much.]]
* Subverted in ''Film/MysteryMen''. The Bowler, a woman whose bowling ball has her father's spirit within, confronts her father's killer. He taunts her, saying that she doesn't have the nerve to take her revenge. He is right; she's a hero and as such above that. Her father, however, is dead and pretty pissed about it and is something of a prick, so he really has no problem killing the guy.
** But played ''perfectly'' straight with Dr. Heller--which makes the heroes ''reject'' his help, until he shows them how effective his inventions can be.
* In the ''Franchise/{{Terminator}}'' series, [[AllLovingHero John Connor]] orders the T-800 to not kill anybody. This carries over to ''Series/TheSarahConnorChronicles''... where both John and Sarah try to live by this, but over the course of the series are forced into taking a life each (see below).
* In ''Film/BlueThunder'', protagonist Frank Murphy is a police helicopter pilot, and he naturally goes to some lengths not to kill anyone (except the BigBad) even while they're trying to shoot him out of the sky. This despite being in command of a heavily armored BlackHelicopter armed with a [[{{BFG}} 20-mm]] [[GatlingGood rotary]] [[MoreDakka cannon]], which has an [[MagicBullets uncanny ability]] to blow away cars, choppers, and aircraft without harming the people inside.
* In ''Film/HotFuzz'', Nicholas Angel aims for incapacitating shots in the final shootout. Despite the several gory murders before, the final shootout sees no deaths.
** Angel's shooting skills were purposely laid out as a ChekhovsSkill early in the film, so it's justified. [[IJustShotMarvinInTheFace Danny,]] on the other hand...
* Recited verbatim by Brother Gilbert in ''Film/{{Dragonheart}}'' before deciding to kill the evil king Einon.
* Surprisingly averted in ''Film/TheAdventuresOfCaptainMarvel'', where the titular hero kills no less than 3 people over the course of the 12 chapter film serial. Given this take on Cap was more of two fisted pulp adventurer than a traditional superhero it makes sense, and he does spare the lives of most of the villains he faces.
* Averted in the Franchise/MarvelCinematicUniverse. [[Film/TheAvengers The Avengers]] have no qualms with killing their enemies, and neither does [[Series/AgentsOfSHIELD S.H.I.E.L.D.]] Which is reasonable, as this is clearly a case of RealityEnsues. Here, in a realistic world, they aren't able to do a hundred backflips and dodge every bullet, knife, and laser thrown their way while hitting every single foe spot-on with non-lethal blows. Here, like in real life, if they've got someone who's about to kill them, they often will have to kill first in self-defense like any other cop or soldier.
* ''Film/XMen'':
** Nightcrawler, given his religiousness...
** Most of the movies have the characters perfectly okay with using lethal force, but this is a specific plot point in ''Film/XMenDaysOfFuturePast''. It's stated that the young version of Mystique never killed anyone (even the people she used her {{Shapeshifter}} powers to impersonate), but [[JumpingOffTheSlipperySlope Jumped Off The Slippery Slope]] when she decided to kill Bolivar Trask. Her decision to kill Trask set off a chain of events resulting in a BadFuture, which is the main reason Wolverine travels back in time to stop her.
* Subverted, in a rather surprisingly brutal way in the movie ''Film/{{Darkman}}''. The protaganist has caught the bad guy from falling to his doom by the pantleg. The bad guys starts into a typical "You can't kill me, you're the good guy..." speech, [[spoiler: and unwisely ends it with the line "you couldn't live with yourself." The protagonist, who by this point has been burned beyond recognition, left for dead surgically altered, and has already killed ''every'' one of his hired thugs(Which he knew about!) promptly lets go of the bad guy, letting him fall to his death, replying "I've had to learn to live with a lot of things."]]
* As in the original series, ''Film/TheLoneRanger'' wants the justice system to deal with the villains rather than take revenge himself, and enforces this trope on Tonto, despite the fact Tonto wants vengeance on Cavendish [[spoiler:and Cole]]. [[spoiler:In the end, Tonto passes up killing Cole... but has no qualms about leaving Cole to his KarmicDeath.]]
* In ''Franchise/StarWars'', the Jedi have compassion for all living things, and so they extremely dislike having to kill someone or something. However, they realize that it is sometimes necessary.
[[/folder]]

[[folder:Literature]]
* Technically, Literature/TheBible doesn't say "Thou shalt not kill", it says "Thou shalt not murder/shed innocent blood". In other words, don't kill someone without a very good reason. Warfare and capital punishment were accepted practice in ancient Israel and in many cases sanctioned by God. Killing in self-defense of your own life, or killing someone who is currently attempting to murder someone else, is likewise permissible and obligatory under Biblical law, as elaborated in the Literature/{{Talmud}}; a would-be murderer is considered legally "dead" for the period of time in which he is attempting to commit murder, and killing them during that period is therefore not considered murder at all. (It is still preferable to stop them in another way if possible.)
** Sometimes God's direct orders violated this commandment, such as His command to massacre the Canaanites, including women and children.
** In the New Testament, Paul quotes that commandment as "Thou shalt not murder". This disagreement might have something to do with the fact that not only did the translators write in an outdated style (for the day, that is), not all of them spoke English on a regular basis. It easily meshes with Christ's teachings as well when you think about it: He said to turn the other cheek when struck, not to offer up the other kidney when stabbed. Sufficient to say, like many parts of the Bible, there [[ActualPacifist are other interpretations]] [[http://en.wikipedia.org/wiki/Christian_pacifism to what this actually means]].
* In the ''Literature/ChroniclesOfThomasCovenant'', the Oath of the Land plays with the ideal of Thou Shalt Not Kill, and takes it further:
-->Do not hurt when holding is enough
-->Do not wound when hurting is enough
-->Do not maim when wounding is enough
-->And kill not when maiming is enough
-->The greatest warrior is he who does not need to kill
* In Creator/JRRTolkien's ''Literature/TheLordOfTheRings'', when Gandalf tells how {{Mordor}} has learned from Gollum that the One Ring is now in the possession of hobbits, Frodo exclaims, "What a pity that Bilbo did not stab that vile creature, when he had a chance!" Gandalf admonishes him:
-->'''Gandalf:''' "Pity? It was Pity that stayed his hand. Pity, and Mercy: not to strike without need... Deserves death! I daresay he does. Many that live deserve death. And some that die deserve life. Can you give it to them? Then do not be too eager to deal out death in judgment. For even the very wise cannot see all ends."
** This really comes down to the difference between killing an enemy in battle (which neither Frodo nor Gandalf shows any aversion to) and ''[[KickThemWhileTheyAreDown executing]]'' [[KickThemWhileTheyAreDown a defeated foe]]. [[spoiler:And as it turns out, Frodo fails in his quest to destroy the One Ring, with Gollum completing it for him... by accident.]] Which could tie into some translations of the trope-naming commandment using "murder" instead of "kill".
** The same mercy is shown to Grí­ma Wormtongue (twice!) and Saruman as well. [[EvilCannotComprehendGood Neither can comprehend mercy]], thinking it's a trick. [[spoiler: As a contrast, Grí­ma kills Saruman at the end.]]
** This is spoofed in the prologue to ''Literature/BoredOfTheRings'', where, after the answer to "What have I got in my pocket?" is demonstrated to be a .38 pistol, the thought behind "pity stayed his hand" is explained as "It's a pity I've run out of bullets."
* Dorden, TheMedic from Creator/DanAbnett's ''TabletopGame/{{Warhammer 40000}}: Literature/GauntsGhosts'' series, pledged not to kill as part of his medical oaths in the backstory. Since our setting is a CrapsackWorld with BlackAndGrayMorality, he has found the going tough, with the one time he was forced to still weighing on him books and years later.
* The Literature/SeekersOfTruth use this, as they work with the law enforcement and justice system. A couple of them violate this rule once, which as it turns out is one time too many.
* Interesting subversion in ''Literature/WarriorCats'', where the warrior code says: "An honorable warrior does not need to kill other cats to win his battles, unless they are outside the warrior code or it is necessary for self-defense.", so Thou Shalt Not Kill... unless it's in self-defense... or the person you're killing ''really'' deserves it. But you are still just considered "dishonorable" (although, being {{Proud Warrior Race Guy}}s, this is AFateWorseThanDeath for some). The rule is still important, though, and main characters have so far only killed {{Big Bad}}s, and at times have had to be restrained from killing others.
* Pulp hero Franchise/DocSavage started out killing bad guys left and right, but evolved a pragmatic "don't kill unless there's no other way" policy after the first few stories. Many a villain ended up fatally HoistByHisOwnPetard. More often than not, Doc knows this is going to happen (since he's sabotaged the weapon) and tries to warn the BigBad, who just laughs and pushes what has now become the BigRedButton.
* An alien race in Creator/TomHolt's ''Literature/FallingSideways'' had this as a rule. They also had a very high level of technology and the collective mindset of a RulesLawyer. As in, it's OK to make people believe themselves to be frogs and eat nothing but flies, because they have a rule saying "Thou Shalt Not Kill" but not "Thou Shalt Not Make People Feed Themselves Horribly Inadequate Diets".
* In ''Literature/TheMysteriousBenedictSociety'' books, Kate's father, Milligan, always works to find solutions that would avoid killing his opponents (generally the vicious Ten Men) no matter how savagely they try to kill him or others. When asked about this by his daughter, Kate, he tells her simply "We're not like them." Indeed, when Kate later has the opportunity to toss a bomb at them and their leader, Mr. Curtain, she instead tosses it away into the water where it can do no harm.
* In the ''Literature/HarryPotter'' series, the rules here are… tricky. Wands are often wielded threateningly like guns, yet the actual Killing Curse, ''Avada Kedavra'', is extremely illegal, and using it ''possibly'' requires some degree of malice. (Perhaps not in the case of [[spoiler:Mrs. Weasley, although Bellatrix was threatening to kill her daughter]], and almost certainly not for [[spoiler:Snape's mercy-killing Dumbledore]]). Nonetheless, there are numerous other spells (like [[spoiler:''Sectumsempra'']]) which would presumably also cause death under the right circumstances. In [[Literature/HarryPotterAndTheDeathlyHallows Book 7]], the disarming spell, ''Expelliarmus'', becomes Harry's pacifistic trademark, and the following conversation occurs:
--> '''Lupin:''' "Harry, the time for Disarming is past! These people are trying to capture and kill you! At least Stun if you aren't prepared to kill!"
--> '''Harry:''' "We were hundreds of feet up! If I Stunned him and he'd fallen, he'd have died the same as if I'd used ''Avada Kedavra''!"
*** Of course, he ''was'' perfectly willing to shoot his pursuers off their brooms earlier and only stayed his hand when he recognised a familiar face in one of them ("familiar" in this case means he'd known him several years ago for a few hours), so his point is a bit shaky.
** When it comes to ultimately dealing with the BigBad, [[spoiler:KarmicDeath it does the trick]].
** The magical world apparently has extremely dim views about killing, since murder can literally ''rip your soul in half''.
* Literature/ArtemisFowl tends to avoid ''any'' killing by the good guys, regardless of possible need or justification. No character at all died in the first book, and the only deaths in the second were [[spoiler:three goblin assassins]], one by KarmicDeath in an avalanche and the other two shot in the back by their accomplice, as well as [[spoiler: the BigBad's second-in-command]] also by accidental KarmicDeath.
* Creator/BrandonSanderson's ''Literature/{{Mistborn}}''-trilogy features the Kandra. A race of [[VoluntaryShapeshifting shape-shifters]] whose own laws forbid them from killing humans. Kandra who break this law are punished by death.
* In ''Literature/TheDresdenFiles'', the First law of Magic specifies that Thou Shalt Not Kill ''With Magic''. Violating this law generally leads to execution by the White Council, except in rare cases where the wizard responsible was judged to be acting in self-defense ''and'' another wizard is willing to mentor the killer. Killing people without magic is allowed if circumstances dictate though. The sole exception to this is [[spoiler: the Blackstaff, who is allowed to kill if it is deemed absolutely necessary]]. Also, the Law specifically states that it is illegal to kill ''humans''. Killing supernatural creatures such as faeries and vampires with magic is allowed, as the Laws only exist to protect humans.
** Technically, the law is to not use black magic, which includes mind control and the like ([[spoiler: Hence Blackstaff]]). It gets into a grey area with regard to collateral damage from magic and largely involves intent as being a key factor, thus making it closer to Thou Shalt Not Murder. Because of the nature of magic in the Dresdenverse, a person must believe in what they are doing. So using black magic and murder actually taints the soul and is very addictive. For what it is worth [[spoiler: The Blackstaff is one of the kindest people in the series, and when he starts unleashing magic to kill it is a horrifying scene. The Blackstaff is allowed to break the Laws because the staff he wields somehow prevents his soul from being tainted.]]
* In the ''Literature/IronDruidChronicles'' Druid magic cannot be used to harm a living being in any way. If you do, the magic will kill you on the spot. However, Druids can kill people in any number of mundane ways like cutting their heads off. The prohibition also only applies to ''direct'' magic use. Druid magic can be used to indirectly hurt someone (e.g. summoning elementals to do the fighting or simply having a hole appear in the earth so the opponent breaks a leg). It also does not apply to supernatural beings with no connection to the earth (eg demons).
* In ''Literature/WearingTheCape'' Hope's expectation is that superheroes follow the Golden Age superhero code, and this is strengthened by Ajax' statement that "heroes don't use guns." But in her first fight she discovers that Atlas is perfectly willing to [[spoiler: let the bad guys kill each other]], and in the surprise-attack on Whittier Base [[spoiler: half the team breaks out automatic pistols, the better to cap their attackers]]. Hope herself [[spoiler: kills an unspecified number of terrorists in the heat of combat, then kills two ''heroes'' in the Dark Anarchist's secret base]].
* In the ''Literature/ChroniclesOfPrydain'', Lord Pryderi taunts the enchanter Dallben, believing that he "secret to his power" is that Dallben cannot kill. Dallben says he has never killed anyone, but that doesn't mean he ''can't.'' [[spoiler:The issue is never settled, since Pryderi [[KarmicDeath dies shortly thereafter]] without Dallben's intervention.]]
* In ''Literature/SeptimusHeap'', Aunt Zelda has to remind Nicko of this when he suggests to make the Hunter remember he's not a lion tamer while he has his head in a lion's mouth.
* In ''Literature/TheQuantumThief'', the Sobornost collective hold a rare, villainous principle in this matter. They could wipe out all their enemies from the Solar System with Strangelet bombs in a matter of hours, but in their ideology, every mind has its place and every memory is worth preserving. It's just happens to be that ''they'' decide what place each mind should have, and they'll cheerfully MindRape the uploaded personalities into any function they find the most suitable, be it an infiltrator or a missile guidance system, and then copy them as needed. In their minds it's only a murder if ''all'' the copies of an uploaded individual are destroyed.
* ''Literature/TrappedOnDraconica'': No matter who it is Daniar will not kill them, though some people really ask for it. [[spoiler: She just about killed Zarracka after the third time she was spared.]] Interestingly, Rana doesn't persuade Daniar out of killing [[spoiler: Zarracka]] out of concern for the villain's well being but to prevent Daniar from breaking her code.
* During ''Literature/GalaxyOfFear'', the protagonists will destroy basic speechless droids and squish beetles [[TheSwarm forming swarms]], and Zak once accidentally kills a birdlike animal and feels remorse, but anything smarter, if it dies, dies some other way. In ''Spore'', Tash flees [[spoiler: [[TheAssimilator Spore]], which is controlling the crew of a]] Star Destroyer and taking it after her into an AsteroidThicket, where it's attacked and destroyed by space slugs. Her ActualPacifist friend, who flew with her, is horrified and feels like she's killed the crew. Tash says it's not the friend's fault, she was following Tash, but also puts the blame on [[spoiler: Spore]].
* Similar to the ''Literature/WarriorCats'', ''Literature/PercyJacksonAndTheOlympians'' downplays the trope. While the demigod heroes do kill monsters, DeathIsCheap with them. They recover in any time between weeks and centuries. On the other hand, Percy deliberately avoids killing other demigods, though it's a bit like Harry Potter's example in that many of them are duped. The views of other demigods aren't really as known but probably were not as merciful.
* ''Literature/TheExilesViolin'': Jacquie is a downplayed example; after killing her father's murderer she swore to herself that she would never kill again but kills {{mook}}s when there is no other option. [[spoiler: At the climax she kills Gunslinger because her rule is not a unbreakable rule.]]
* ''Literature/{{Discworld}}'': Witches consider this an important part of their ideology, hence why they often use LaserGuidedKarma on their enemies. Good witches practice this because [[CaptainObvious life has value]], or else [[CruelMercy because death is]] [[FateWorseThanDeath too good for the villain]]. Conventional bad witches, such as the late Black Aliss, also don't kill [[IShallTauntYou because you can't rub a dead enemy's nose in your victory]]. (Even evil curses come with FantasticFragility for similar gloating-related reasons.) Actually murdering someone is treated as crossing the MoralEventHorizon by all parties nearby.
* In ''[[Literature/ElementalMasters Steadfast]]'', Kate's teachers impress upon her the need to not simply call on her Elemental allies to burn her [[DomesticAbuse abusive husband to ash]]. It's not that he doesn't deserve it, but her teachers don't want her to taint the innocence of her Elementals by using them to kill humans. This is specific to Kate and her teachers; using elementals to kill is elsewhere not considered to be BlackMagic.
* In ''Literature/ABrothersPrice'' the protagonists do kill frequently when the need arises, but never with Jerin, the male protagonist, present. In one situation, a woman gives one of their enemies TapOnTheHead, and reassures Jerin that no, she didn't kill her, and she is extremely sorry that he has to witness this. [[spoiler: Later Jerin shoots a woman himself, and is shocked for moments afterwards. He did it in defense of his rescuer, Cira, and is extremely upset that he actually killed a human being.]] While reference to execution as punishement is made, a proper court proceedings beforehand is seen as preferable to killing in self-defense whenever possible. And even then, the protagonists don't like the thought of small children being executed for their mothers' crimes (as is the normal course of action, to avoid [[YouKilledMyFather revenge being taken by the surviving offspring.]])
* In ''Literature/DragonBones'', Ward, the protagonist, does kill in battle, but feels extremely bad about killing in cold blood when his life is not in immediate danger. He could have easily killed his abusive father, but never did, even though his father told him about the KlingonPromotion for which he killed Ward's grandfather. His reluctance to kill comes up later, when [[spoiler: Oreg reveals that the only possible way to prevent the villains from winning is to kill ''Oreg'' - his life is bound to the castle in which the villains currently are, and killing him will make it collapse. Ward feels it goes against his very nature to kill someone he should be protecting. In the end, he does it, but falls into a kind of grief-induced coma afterwards.]]
* In Jeramey Kraatz's ''Literature/TheCloakSociety'', the Cloak members were shocked when, in the BackStory, Lone Star killed many of them to stop their plot. They jeer at him as a killer. [[spoiler:Later, Alex learned how deeply this had scarred Lone Star.]]
* Taken as gospel by Gary Karkofsky in ''Literature/TheRulesOfSupervillainy'' as how superheroes should act. Notably, this idea is given a LampshadeHanging by the fact Gary is the hero of the book and frequently kills but justifies it as he's a ''supervillain.'' Plus, all of his victims are psychopathic murderers much worse than him. This, ironically, makes him identical to the NinetiesAntihero type characters he despises.
[[/folder]]

[[folder: Live Action TV]]
* ''Series/{{Arrow}}'': After five or so years of semi-righteous [[TheStraightAndArrowPath murder]] left and right, [[AntiHero Oliver]] [[TheCowl Queen]] attempts to do his vigilante work with [[HeroicVow less collateral damage]] (barring that of [[HeroInsurance property]], of course) after [[spoiler: [[HeroicBsod Tommy's death]]]]. However, this trope is danced around, as he [[spoiler: [[UnstoppableRage instinctively]] [[NoKillLikeOverkill puts three arrows]] in [[EvilIsHammy Count Vertigo]] when the latter [[ForTheEvulz grinningly]] [[AndYourLittleDogToo threatens]] [[TheHeart Felicity]]. And all this mere weeks after the vow is made, too]]. His resolve is nowhere near as strong as that of [[Franchise/{{Superman}} his]] [[Franchise/{{Batman}} counterparts]].
-->'''Oliver (on choosing to [[spoiler: kill the Count]]):''' [[spoiler: Felicity... he had you and he was gonna hurt you. [[IDidWhatIHadToDo There was no choice to make]].]]
* ''Series/BuffyTheVampireSlayer'': Slayers are definitely not ''supposed'' to kill humans (even villainous humans). Vampires and other assorted demons are fair game. Although there were a number of {{Karmic Death}}s for the human enemies. There was also that time she had to kill about ten of the [[WellIntentionedExtremist Knights of Byzantium]] to defend herself and her sister, one by ''throwing an axe into his chest at pointblank range''.
** After [[spoiler:Faith accidentally kills a human with a wooden stake while still on a massive adrenaline rush after a fight, seconds after Buffy tries to warn her]] Giles actually tells Buffy that due to the high-stress nature of the Slayer's job, the Watcher's Council expects one or two accidents and has ways of dealing with them. This doesn't stop the angst on the part of the accidental murderer, though. [[spoiler: An episode soon after shows Buffy stopping just short of the killing blow to a vampire after Willow cries out, in exact parallel to the situation with Faith, showing that Faith could have avoided killing the deputy mayor if she had a clearer head.]] Shortly afterwards, [[spoiler: Faith's poisoning of Angel drove Buffy to nearly kill her so that her blood could be used as an antidote. Thankfully, Faith was only put in a coma and Buffy snapped out of killer mode, though actually entering it in the first place haunts her for a good long while.]]
** [[{{Discussed}} Mentioned]] in one episode when Ethan Rayne tells Buffy she can't do anything to him since he's human, only for [[GovernmentConspiracy The Initiative]] to arrest him.
** The same rule also generally applied to ''Series/{{Angel}}'', though he had quite a few "exceptions" to it throughout the series' course. Humans were excluded if they had supernatural powers. Even then there was the episode "Conviction" where Angel killed a special ops soldier who was technically his employee by kicking him causing him to shoot himself in the head, just to make a point that the soldier's way of doing things wasn't going to be tolerated anymore under Angel's management.
* ''Series/{{Heroes}}'': Matt Parkman had ample justification to kill Emil Danko, who is heading a program started by Nathan Petrelli to round up persons with special abilities. First, Danko's operatives [[spoiler: shoot Matt's girlfriend Daphne.]] Then when Danko takes control of the operation [[spoiler: he removes the still-living Daphne from the medical facility. Consequently, Daphne develops sepsis, leading to her death.]] Parkman seeks to get even by taking away the most important person in Danko's life, a call girl named Elena who knows Danko as "Jakob Pradasa". He [[spoiler: telepathically forces Danko to divulge his true identity, to admit what he does (hunting and abducting people), and to confess that he let Daphne die.]] Parkman then [[spoiler:points his gun at Elena, but cannot bring himself to shoot her.]]
* ''Series/{{Supernatural}}'': Hunters are supposed to kill evil monsters and protect humans, but just like ''Series/{{Buffy|the Vampire Slayer}}'' example above, killing humans is not acceptable. The one time the Winchesters considered killing a human, WellIntentionedExtremist Gordon Walker (who thinks Sam is purposely evil), he gets [[KarmicTransformation turned into a vampire]] (his specialty) so that Sam can kill him without feeling really guilty about it.
** However, when up against truly [[HumansAreBastards monstrous]] humans (like the family who hunts other humans for sport or the other one with feral children who were bloodthirsty {{Tyke Bomb}}s), Sam and Dean have had to kill. As Dean said "Demons I get, humans I don't."
* ''Series/TheSarahConnorChronicles'' starts off with John and Sarah like this. Derek and Cameron, not so much. Sarah frequently orders either or both of them not to kill (they tend to take it under advisement). The first season features Sarah's reluctance to kill a man she believes will one day create Skynet, and is shown dwelling on it. A common theme throughout the series is the importance of human life. However, Sarah ends up being forced to kill a man midway through season two and John even earlier.
* ''Series/DoctorWho'': This is the Doctor's [[TechnicalPacifist apparent]] modus operandi. Give him points for effort, but it doesn't usually work.
** Of course, depending on just how far an enemy pushes him, he might make [[BeCarefulWhatYouWishFor them]] [[OhCrap genuinely]] [[FateWorseThanDeath wish]] [[BewareTheNiceOnes he]] [[AndIMustScream just]] [[WhoWantsToLiveForever killed]] them.
** Heavily subverted in the seventh season episode "Dinosaurs on a Spaceship". Sure, that guy had committed [[ThrownOutTheAirlock genocide]] on an entire [[TheArk shipload]] of refugees and tried to [[MadeASlave enslave]] queen Nefertiti of Egypt. Being used as [[MisguidedMissile a missile decoy]] was the least he deserved, but coming from the Doctor that was cold.
** Completely subverted by the creation of the War Doctor whose entire purpose was to bring about the swift conclusion of the Time War in the most efficient manner possible regardless of how many deaths that caused. He outright asks to be made into a Warrior when he starts that regeneration cycle.
* In ''Series/{{Smallville}}'', Clark Kent refuses to kill enemies, but he does not consider KarmicDeath or accidental death to be murder. The one time he attacked an opponent ([[WorthyOpponent Titan]]) with the intent to kill, he was haunted after he did the deed. Chloe also stresses this often, sometimes to meteor freaks who aren't bad at heart. [[AntiHero Oliver]] [[IDidWhatIHadToDo on the other hand]]... It leads to clashes between him and both Clark and Chloe. He often tries to get them to do what he does.
--->'''[[TheHeart Chloe]]''': This is ''murder''.
--->'''Oliver''': This is ''justice''.
** Clark also doesn't hesitate to [[spoiler:kill Brainiac]], justifying it with the lame technicality that [[spoiler:Brainiac [[WhatMeasureIsANonHuman is a robot]]]].
** In another episode, Chloe admonishes Clark that he should not hesitate to let her die if that's what it takes to save the world.
* In the 1998 miniseries ''{{Series/Merlin|1998}}'' (the one with Sam Neil), this is the limitation of the magic of TheFairFolk, that it cannot be used to kill, [[AllThereInTheManual according to the novelization]].
* The [[EldritchAbomination Leviathans]] of ''Series/DarkShadows'' have this as a rule. Not due to any sort of morality, but rather because anyone they kill will become a super-powered ghost, capable of hindering their plans even further. At least that's how it's supposed to work, but due to RealLifeWritesThePlot issues the matter was rather derailed.
* Michael from ''Series/PrisonBreak'' fluctuates between this and TechnicalPacifist.
* In ''Series/HaveGunWillTravel'', Paladin will avoid killing if possible, and more than one episode ends without anyone dying. When it becomes necessary, however, he won't hesitate.
* ''Series/{{Tracker}}'' Cole does not kill; he just incapicates the human long enough to withdraw the life force from the body. Justified, because Cirronians are a peaceful species by nature, and abhor violence (yes, even the criminals-most are in prison for nonviolent crimes).
* Gabrielle, of ''Series/XenaWarriorPrincess''.
* In the pilot episode of ''Series/TheIncredibleHulk'', David Banner's research partner assures him that the Hulk will not kill, "because David Banner wouldn't kill." Nevertheless, David spends the series worrying that the Hulk will one day cross the line. (He doesn't, but only because so many of the bad guys are MadeOfIron.)
* Shepherd Derrial Book from ''Series/{{Firefly}}'' follows the Ten Commandments to the letter, including the TropeNamer. However, he rather dryly notes in "War Stories" that the Bible is "somewhat fuzzier on the subject of kneecaps." In ''Film/{{Serenity}}'', after shooting down [[spoiler:the Alliance gunship that just mortally wounded him and burned his town to the ground]], he comments that it was "not very Christian of me." This is explained somewhat in the comic books: [[spoiler:He spent the GreatOffscreenWar doing black ops, including assassinations, and is now TheAtoner.]]
* The Shaolin philosophy from ''Series/KungFu'' has this as one of it's core tenets. "Avoid rather than check. Check rather than hurt. Hurt rather than maim. Maim rather than kill. For all life is precious nor can any be replaced."
* Played completely straight with the title character of ''Series/MacGyver'', due to a childhood incident in which [[spoiler:he accidentally caused the death of one of his friends with a handgun they'd stolen to play with]]. Occasionally comes across a strong temptation to use one, but always [[TakeAThirdOption finds another way]]. In one of the TV movies, the terrorist group he's trying to infiltrate orders him to [[IfYoureSoEvilEatThisKitten execute one of their defeated members]]: he reacts by [[spoiler:emptying the clip right over the terrorist leader's head for effect, shouting that only a stupid leader would waste his men's lives like that, and pretending to walk out by saying he was looking for "professionals, not suicidal punks."]] [[RefugeInAudacity It works]]. Furthermore, it's so deeply ingrained in him that even on the couple occasions he loses his memory and finds himself pointing a gun at somebody, he can't make himself pull the trigger.
** The only time we've seen him in a nearly murderous rage was right after catching a racist who'd had one of his best friends lynched, whom he caught in the middle of printing his white power pamphlets, and who wasn't so much bragging about it as shrugging the whole thing off (oh, he also tries to shoot him). A cop calls him back to his senses just before he can deliver a no-holds-barred and possibly fatal beating.
** In an oft-cited case of EarlyInstallmentWeirdness, the pilot episode does feature Mac picking up a machine gun and returning fire against Soviet troops. This might not be an aversion, though - he only fires once or twice and we don't see anyone being hit, so it's easy to write off as simple covering fire to give himself time to escape.
* Less cut and dried with the main characters of ''Series/TheATeam.'' They never kill anybody onscreen, but it's not clear how much of this is due to their own methods, and how much of it is just the television show trying to remain family friendly (especially since they get into gunfights on a regular basis and we often see people surviving things that would clearly be fatal in real life). No one in the A-Team has a strongly voiced opinion against killing and even less against guns - as Vietnam veterans and a former Special Forces unit, it's a foregone conclusion that they ''have'' killed people before. At the same time, they routinely pass up opportunities to kill enemies that they have at gunpoint, and much prefer to simply beat the tar out of the villains and leave them tied up for Colonel Decker to put in jail.
* In ''Series/TheFlash2014'', Leonard Snart/Captain Cold is a petty thief turned supervillain who doesn't kill if he can help it, but will if forced to or crossed. After Flash challenges him to continue his supervillain career without killing anyone, he accepts, seeing it as a true test of his skills.
[[/folder]]

[[folder: Newspaper Comics]]
* In the storyline which introduces Bluto, ComicStrip/{{Popeye}} has to use his most powerful punch, and is extremely worried about Bluto's survival. This happened in 1932, [[OlderThanTheyThink before either Marvel or DC was even founded]].
[[/folder]]

[[folder:Radio]]
* ''Radio/TheLoneRanger'', in some ways a precursor to Vash, used silver bullets as a symbol of his pledge never to take human life.
[[/folder]]

[[folder: Tabletop Games]]
* ''TabletopGames/{{GURPS}}'' has the Pacifist disadvantage, which comes in several flavors, one of which is Cannot Kill. Characters with the "Cannot Kill" disadvantage can start fights and use any tactics they like, but they cannot kill, or be responsible for a death, or leave a wounded enemy to die. They also cannot stand by while their teammates administer the CoupDeGrace. If they do, they {{angst}} about it for days and are effectively rendered useless to the team.
* Some Superhero {{RPG}}s would invoke rules against killing. Two notable examples were ''Marvel Super Heroes'' and ''DC Heroes'', which would eliminate all Karma/Hero Points (a combination of experience points, and self-boosting reserves for various tasks) and keep you from accumulating more for the rest of the adventure (usually one night of gaming). In DC heroes, this punishment came from using lethal force at all.
* ''TabletopGame/DungeonsAndDragons'' has the Book of Exalted Deeds, which contains the feat "Vow of Peace". It grants benefits as long as you don't inflict lethal damage, allow an ally to finish off a defeated opponent, or cause similar harm to a creature. It takes this trope to extremes; accidentally swallowing a gnat in your drinking water will cause you to lose the benefits of the feat, in fact the feat specifically references paladins drinking their water through a strainer. It doesn't really make you a pacifist, [[TechnicalPacifist technical]] or [[ActualPacifist actual]], though; you can still fight all you want, as long as you never inflict lethal damage.
* "Code vs. Killing" is one of the most commonly seen Psychological Limitations in ''{{Champions}}'', usually bought as "total commitment" (i.e. the character can't bring him- or herself to kill at all and won't stand idly by while others do it either). Normal people are already assumed to be "reluctant to kill" by default (being AxCrazy would be its own different Limitation); the code, if taken, is intended to go beyond well beyond that to proper comic book levels. Of course, being a Limitation that you get points for, it's also ''supposed'' to cause your character trouble from time to time.
* In the OldWorldOfDarkness, Lifesaver was a 3 point flaw, and Flaws generally maxed at 5 for things like Dark Fate. It made you unwilling to take life. Pacifist was a 5 point flaw and was taken literally - the character could do no physical harm to others.
[[/folder]]

[[folder: Video Games]]
* The MMORPG ''VideoGame/CityOfHeroes'' takes this to its natural extreme: the player-characters are always sent to "arrest", "defeat", or just plain "stop" the villainous {{NPC}}s, and even if the enemies are "arrested" with a high-powered assault rifle, a broadsword, or repeated fireballs, nobody ever dies. Instead, they're sent to the local CardboardPrison, The Zig. [[WhatMeasureIsANonHuman That's just for human enemies]]. Robots explode, rock monsters crumble, and spirits are banished.
** WordOfGod has stated that it's up to players what happens to the {{Mooks}} -- they could be killed or not, depending on how players roleplay. Named enemies are usually explicitly captured. Robots and rock monsters are confirmed to be non-sentient, the former having no real intelligence and the latter just being the fingers of a massive and powerful ball of jello. The various banished spirits are truly and completely immortal, so banishing doesn't kill them.
** ''VideoGame/CityOfVillains'', however, sees it quite differently: There are several missions where you're explicitly told to 'kill' someone, or to 'LeaveNoWitnesses'.
* Used occasionally in ''VideoGame/FireEmblem: Path of Radiance'', funnily enough. In chapter 15, you get bonus points for not killing any enemies except the boss (except you don't really kill him), and in chapter 22 you get bonus points and a gift for not killing any priests.
** [[TheHighQueen Queen]] [[FriendToAllLivingThings Elincia]] in ''[[VideoGame/FireEmblemTellius Radiant Dawn]]'' has a unique special skill called [[ExactlyWhatItSaysOnTheTin Mercy]], which allows her to blast her foes down to 1 HP, but...
* Maintaining the same belief in the comics, Batman in ''VideoGame/BatmanArkhamAsylum'' never kills. According to his detective mode, his enemies always wind up unconscious. Yes, even the ones who have been punched in the face, or had a wall they were standing in front of blown up. Unconscious, every one.
** The game has many ways of preventing you from killing enemies, bordering on TheDevTeamThinksOfEverything territory. Knock a guy off a tower, and Batman automatically attaches a cable to his foot. Throw a Mook down a bottomless pit and you hear a splash right away, implying that there's water just out of sight. There's even an invisible wall around the pool of electrified water, so you can't throw anyone in (Batman can still fall in himself, though).
*** The sequel ''VideoGame/BatmanArkhamCity'' extends this selective invisible wall to all of the many rooftops Batman fights on. Pay no attention to the fact that he's beating people into immobility, and leaving them lying around unable to defend themselves in a city filled with psychopaths, while they're wearing light clothing in the middle of winter.
** Taken to the extreme in ''VideoGame/BatmanArkhamOrigins'', where in the finale, Joker is so hellbent on forcing Batman to kill someone [[spoiler:he connects a heart monitor Bane is wearing to an electric chair, which the Joker is sitting in. Either Batman kills Bane, the electric chair kills Joker, or Bane kills Batman. How does Batman solve this situation? He ''puts Bane into cardiac arrest'' so that his heart stops long enough for Gordon to secure the Joker, then uses his shock gloves to ''bring Bane back to life'', knowing that Bane will try to kill Batman as soon as he wakes up again... and he does, leading to the boss battle with Titan-Infused Bane.]]
** [[https://www.youtube.com/watch?v=hCl0Qv8DkvQ As pointed out by Outside XBox]], the people Batman nails in the head with propane tanks, drags off the GCPD roof to a multi-storey fall, pummels in the face at point-blank with "less-than-lethal" ammunition, or clonks in the throat with a car door should really not be as alive as Detective Mode claims they are.
* In the NES Batman game, Batman averts movie canon and hurls the Joker off the cathedral. [[HesDeadJim The rest of the ending is spent zooming in on the Joker's corpse.]] Then it plays it straight with the [[DirectToVideo NES only sequel]], ''Batman: Return of the Joker''.
* In ''VideoGame/MortalKombatVsDCUniverse'', to keep with their credo, the heroes of the DC universe get "Heroic Brutalities" instead of [[FinishingMove Fatalities]], moves that punish the enemy without killing them... or so it's supposed to be. In practice, [[FridgeLogic crushing a person's body in a Green Lantern orb isn't exactly nonlethal]]. Neither is Superman pounding someone into the ground like a hammer to a nail.
* ''VideoGame/{{Touhou}}'' features a Spellcard System that is explicitly designed to [[NonLethalKO prevent the death of anyone using its rules]]. This allows the {{youkai}} the ability to try and kill the BarrierMaiden heroine, without the risk of destroying their world, while giving Reimu a fighting chance at defeating [[PhysicalGod absurdly overpowered monsters]] with abilities like [[SuperpowerLottery the ability to kill with just a thought, total immortality,]] and [[RetGone the ability to drop someone out of existence]]. Reimu has the ability to go invincible, so it's usually more helpful to her opponent.
* ''VideoGame/InFamous'' has an interesting way of handling this. Killing your enemies in a fight doesn't affect your KarmaMeter, but killing enemies who are already bound is marked as an "Execution," which gets you bad karma.
** Sort of. As you gain Good Karma, your default attacks get replaced with "stun" weapons. Obviously you are still probably killing a lot of them so it is sort of true, but it rapidly falls into the category of MercyBullets and the like, plus when you "take down" an enemy, killing them doesn't get you any Karma but Arc-Restraining them gets you Good Karma. Also, Bad Karma lets you get more Bad Karma as you kill enemies in combat.
* It is strongly implied in ''VideoGame/SpiderManShatteredDimensions'' that the player never kills anyone. This is {{Lampshade|Hanging}}d in the tutorial, when ''ComicBook/SpiderMan2099'' throws a {{Mook}} off an elevated bridge, only to have Madame Web whisk him to safety via a dimensional portal. Also, Spider-Man Noir doesn't have [[SuperheroPackingHeat his pistol from the comics]]; its absence is never acknowledged.
* In the ''VideoGame/{{Thief}}'' series, higher difficulty levels prohibit players from killing the guards, presumably not out of morality but for the sake of stealth and forcing them to rely on other means of defeating or evading them.
** This could also be for the idea behind Thief that a true infiltrator would not leave any means to suggest they'd been there. A trail of corpses would most likely be noticed, no matter how stupid the guards may seem.
*** In the first level of Thief 2: The Metal Age, Garrett is not allowed to kill any guards on any difficulty level. This is because the target he is to help escape would be distraught if anyone were to be killed over her.
* In ''VideoGame/RyuGaGotoku'', no matter how much of a criminal the main characters are. They do not have the murderous impulses of their CrimeSandbox brethren. It is often used to separate the honorable and dishonorable characters. For Kiryu, his reason for not killing was after the deaths of the only 3 people he considered family, and his vow to renew his life by being Haruka's father-figure.
* Carol's response in the titular ''VideoGame/CarolReedMysteries'' when you try to shoot her attacker at the end of [[spoiler:Amber's Blood]] is a shocked "No, I'm not going to shoot anyone!"
* ''VideoGame/KingsQuestMaskOfEternity'': Thrown out the window, unusually for a ''King's Quest'' game.
* Luna in ''VisualNovel/VirtuesLastReward'' never, ever picks "Betray", which can kill a person if their BP gets low enough. Justified, since she's [[spoiler:ThreeLawsCompliant]].
* ''VidoeGame/FinalFantasyIX'' has this [[spoiler:When all that's said and done, Kuja admits his own wrongdoings and does a HeelFaceTurn, but unfortunately [[RedemptionEqualsDeath at the cost of his own life.]]]]
* Bang Shishigami of ''VideoGame/BlazBlue'' has this epithet as a memento from his master, Lord Tenjo. No matter what wrongdoings someone does, he will not move to kill them; even Jin Kisaragi, the man responsible for killing Tenjo, is only to be "brought to justice" in Bang's eyes. On the other hand, Bang is sworn to protect the lives of children, and that vow supersedes this one, as he sought to (unsuccessfully) demonstrate to Hazama over beating Tao and Carl to near-death [[ForTheEvulz as a masturbatory aid]].

[[/folder]]

[[folder: Web Comics]]
* In ''Webcomic/SluggyFreelance'', Torg made Oasis swear one of these vows. She sorta forgets it for a while and becomes an AllCrimesAreEqual vigilante. When she remembers, she cries, "I've broken my promise! There can be no wedding! ''Why does love bring me nothing but pain?''" Ironically, Torg himself doesn't really subscribe to this philosophy, as he was perfectly willing to go in guns blazing and swords swinging during "The Stormbreaker Saga" and "Dangerous Days" arcs.
* In ''WebComic/TheAdventuresOfDrMcNinja'' [[spoiler: Mongo the superninja has learned the preciousness of life.]] [[{{Frankenstein}} And also]] that [[AltText fire bad]].
* ''Webcomic/DemonFist''
** The Demon Fist almost never kills humans or peaceful demons, even (especially!) {{Mooks}}.
** Neither does the Hookshot crew. This pays off for them later.
-->'''Duncan:''' Your crew fought off all my men without killing any of them. Criminals would not have wasted the effort not to kill their attackers. I can't in good conscience take you all in simply for defending yourselves.
* Decoy Octopus of ''WebComic/TheLastDaysOfFoxHound'' passes The Sorrow's test because he has never killed anyone and thus has no one to face. The Sorrow is ''very'' surprised and Octopus just shrugs, claiming he's more suited for espionage than fighting.
[[/folder]]

[[folder: Web Original]]
* This trope was actively enforced in the ''Roleplay/GlobalGuardiansPBEMUniverse''. Player characters who were [[AxeCrazy casual killers]] were absolutely not welcome, and those that became it later were booted from the game. Accidents still happened, but for the most part the idea the various campaigns operated under was that real heroes didn't kill criminals. The single exception was the ''Big Easy'' campaign, but as that campaign was based on UsefulNotes/TheDarkAgeOfComicBooks, it got a pass.
* Shortly after 9/11, WebSite/TheOnion reported that {{God}} [[http://www.theonion.com/articles/god-angrily-clarifies-dont-kill-rule,222/ held a press conference]] to remind everyone exactly what He meant by "Thou Shalt Not Kill."
[[/folder]]

[[folder: Western Animation ]]
* ''WesternAnimation/BatmanTheAnimatedSeries''
** In "The Underdwellers", the villain Sewer King uses a small army of abandoned children to steal and commit crime for him, punishing them cruelly when they fail. Batman corners him at the end of the episode and angrily shouts that although he realizes that passing judgment is a matter for the courts, he's ''sorely tempted'' to take matters into his own hands.
** In "His Silicon Soul", the robot copy of Batman that Hardac created in a final attempt to gain revenge on Batman and KillAllHumans follows his human template's example all too well. The robot has a HeroicBSOD when it thinks it killed Batman during their fight and sacrifices itself to foil the scheme it had earlier set in motion when it realizes more people will die because of it.
* In ''WesternAnimation/BatmanBeyond'', Terry seems to have an attitude somewhat similar to the ''Film/BatmanBegins'' version of Batman: the series makes it a specific point that he won't kill in cold blood, and he generally tries to make sure his villains rot in jail, but he often won't go very far out of his way to save them, either. He's also consistently willing to use lethal force in the heat of combat, usually in the form of [[CombatPragmatist combat pragmatism]] such as chucking handy barrels of toxic waste.
* In ''WesternAnimation/JusticeLeague'', an alternate universe episode sees the Flash die by Lex Luthor's hand, to which Superman responds by killing his archvillain in a gruesome fashion. These events eventually draw the default universe's Lex Luthor to try to ruin Superman by goading him into the same murderous rage. Late in this arc, the Flash appears to sacrifice himself to stop Lex's grandest scheme, to which Lex defiantly gloats. Superman hoists Luthor in front of his face and bitterly growls, "I'm ''not'' the Superman who killed Lex Luthor. Right now, I wish to heaven I were, but I'm ''not''."
** The prime universe Superman made an exception for Darkseid in "Twilight". After Darkseid's latest gambit to conquer the universe, Superman has had it with the tyrant and stays behind on the exploding asteroid so he can kill Darkseid with his bare hands. The only reason he doesn't manage it is because Batman pulls him and Orion into a Boom Tube to save them. As it stands, Superman does manage to kill Darkseid by trapping him on the self destructing asteroid. It even sticks for four whole seasons. Notably, he spared Darkseid the first time he beat him, and this is when Darkseid had nearly (indirectly) killed Supergirl. Kara herself persuaded him from killing Darkseid that time though.
** In the series finale, Superman subtly expresses his hopes that Darkseid and Lex Luthor are dead for good, without his having to kill them. He is so hopeful that five of the other founding seven have to [[DeathIsCheap convince him otherwise]]. According to WordOfGod, [[spoiler: Superman was actually right this time. Darkseid and Luthor both became part of the Source Wall.]]
* ''WesternAnimation/HeManAndTheMastersOfTheUniverse1983'': He-Man seemed to live and die by a code of not killing anyone (which explains why the same villains keep coming back again and again). This causes a crisis of conscience in one episode where he believes he has allowed someone to be killed [[spoiler: but it was actually [[ThePlan a trick by Skeletor]] to make him give up his powers]].
* Aang in ''WesternAnimation/AvatarTheLastAirbender'' is more than willing to use violence if necessary, but draws the line at killing. While he doesn't complain when his friends use potentially lethal force against soldiers, he does take issue when they suggest deliberately killing someone (Katara avenging her mother). This weighs heavily on him in the finale, where he is faced with the possibility that killing Fire Lord Ozai may be the only way to end the Hundred Year War, and pretty much everyone is telling him that he's going to have to do so despite his reservations. He then tries communing with the spirits of previous Avatars, hoping one of them will provide a non-lethal solution, but they too say he'll have to kill Ozai. Even the previous Air Nomad Avatar, who shared Aang's religious objection to killing, says that as Avatar his duty to protect the world is more important than his personal beliefs. [[spoiler:[[ContrivedCoincidence Good thing he just happens to come across someone who has the perfect solution to his problem, eh?]]]]
** This is averted by Aang's successor Korra in the SequelSeries ''WesternAnimation/TheLegendOfKorra'', who is not only more violent than Aang, but has shown that she is willing to kill, even when it isn't strictly necessary. When Tarrlok pressed her BerserkButton one too many times and started a fight, she implicitly intended to kill him for it even after he was rendered defenseless (he used bloodbending to stop her). In the following season, she blatantly threatens to murder a judge when he sentences her father to death for supposedly trying to kidnap her uncle, then chases him down and threatens him further when the sentence is reduced to life imprisonment. When she thought her father was killed by Zaheer in Book 3, she likewise threatened to kill him (that didn't pan out, though not for lack of trying). She also actually kills [[spoiler:[[ShootTheDog Unalaq after his fusion with Vaatu]]]], though she regrets having to do so. Korra's allies haven't shown any aversion to lethal force, either; in the Book 3 finale, [[spoiler:P'Li is killed by Suyin and Mako kills Ming-Hua]].
* ''WesternAnimation/{{Gargoyles}}'' has an interesting relationship to this trope. In the modern day, the Clan is generally averse to killing. In the flashbacks to Scotland, though, they don't seem to have any problem with it. At one point, Goliath spells it out that killing someone in the heat of battle was alright. Just attacking someone with the intent to kill, however, was murder.
** Averted near the end of the series where a family hunting Demona nearly kill Goliath's daughter. He declares that he will "hunt them down. And I will ''kill'' them." He doesn't (initially) change his mind either; the next time he sees them, he tries to kill them by hurling them into a wall of electrical equipment. They only survived because they had special armor on that absorbed the damage. Apparently, the writers had to fight tooth and nail to let [[NeverSayDie that line]] stay in as it was.
*** It's even more complicated. From a cultural standpoint, revenge is an acceptable response within Gargoyle society, to the point of it being honorable (at least for the Scottish Clan). Probably for the sake of family-friendliness, one of the first lessons the Gargoyles seem to absorb is that the modern day justice system is now the proper outlet for punishing transgressors. But as mentioned above, that isn't always good enough for the heroes.
* In ''WesternAnimation/CaptainSimianAndTheSpaceMonkeys'', the titular heroes' SufficientlyAdvancedAlien benefactors supply them with non-lethal weaponry, presumably because of this trope.
* In ''WesternAnimation/TeenTitansTroubleInTokyo'' Robin gets in some trouble with the law when it looks like he killed the supervillain he was fighting. In [[WesternAnimation/TeenTitans the series itself]], however, the episode "Aftershock" [[AvertedTrope averts]] this trope. While the other Titans were holding back, Raven's words and actions indicate she was genuinely trying to kill Terra when they fought. Later [[spoiler:Terra decides to pull a HeelFaceTurn and stops working for the villain Slade; she accomplishes this by throwing Slade into a pit of lava.]]
* In the 1960s cartoon ''WesternAnimation/TheNewAdventuresOfSuperman'', Superman (yes, Superman) kills his opponents at least twice, although they might fall under WhatMeasureIsANonHuman: The first is when he causes a group of possibly sapient "lava men" to revert to being just ordinary lava, and the second is [[GoingToGiveItMoreEnergy when he consciously and deliberately allows the Parasite to absorb all of his power, knowing that the Parasite cannot contain so much power.]] Superman is right, and the Parasite explodes. On screen. Oh, and this version of the Parasite isn't a weird-looking purple humanoid. He's a heavy-set man with a strange power.
* Although killing is rarely touched upon in the show, ''WesternAnimation/CodenameKidsNextDoor'' seems to somewhat demonstrate the KND, and some villians going by this trope. They instead try to subdue each other as a means to win fights; respectively, the KND would subdue and apprehend villains to imprison them in Arctic base, while the non-killing villians merely do whatever they have in mind with KND Operatives once they overpower them.
* A ''WesternAnimation/RobotChicken'' skit had Franchise/{{Batman}} managing to get past his code by giving the court a testimony that ends with SelfDemonstrating/TheJoker getting the death penalty.
-->'''Batman:''' [[SarcasmMode "It's erm]], [[LoopholeAbuse out of my hands."]]
* In ''WesternAnimation/DanVs'', the [[VillainProtagonist title character]] is a violent JerkAss with a HairTriggerTemper who will go to a RoaringRampageOfRevenge for the [[RevengeBeforeReason most]] [[EvilIsPetty minor of]] [[DisproportionateRetribution inconveniences.]] But he draws the line of killing his offender and takes offense when someone suggests it.
** More PlayedForLaughs, but Dan was pretty surprised when his best friend [[BigEater Chris]] admits that he would kill for [[BaconAddiction bacon.]]
** Worth noting, however, that in the pilot, Dan was [[EarlyInstallmentWeirdness all too willing to kill a library patron]] because it furthered his goals at the time. Chris talked him down, but a passing vehicle took the whole thing out of their hands anyway.
** In essence, Dan's willingness to kill depends on two factors: exactly how irrational he is at the moment (and he's almost always on some level of insanity) and RuleOfFunny.
** Dan also only seems to be averse only to killing his offenders directly. He's perfectly fine with encouraging others to do so.
** There are also a number of times where Dan's revenge ''should'', by all logic, kill his offender, but they survive because of RuleOfFunny.
[[/folder]]

[[folder: Real Life]]
* [[UsefulNotes/JoanOfArc Saint Jeanne d'Arc]] took this very seriously, ''despite being called to lead the French army to victory (from the front!)''. As she herself stated at her trial, "I have told you often enough, that I have done nothing but by the command of {{God}}. It was I, myself who bore this banner, when I attacked the enemy, to save killing any one, for I have never killed any one."
* Just like his counterpart in ''Film/{{Goodfellas}}'', the real life Henry Hill (who was a big time gangster) claims to have killed no one. [[UnreliableNarrator In reality he is known to have killed at least three people.]]
* One of the Ten Commandments is usually written as Thou Shalt Not Kill, though experts disagree on the translation and interpretation. Some people who follow the Bible, and the Commandments, find justifications in extreme situations, as with Christians who go to war, or Jews who fought back against Nazis. It's generally seen as a prohibition against ''murder'', meaning that killing in war is at least sometimes justified.
** Jesus commanded Peter to put his sword away, and told him that those who live by it, also die by it. This could be a New Testament account of Jesus' statement on pacifism, especially killing.
** The very same book that contains the Commandments also contains [[BurnTheWitch "Thou shalt not suffer a witch to live"]] in the King James Version, however this version alone explicitly included the phrase. Others simply say:
--->"Let no one be found among you who sacrifices their son or daughter in the fire, who practices divination or sorcery, interprets omens, engages in witchcraft, or casts spells, or who is a medium or spiritist or who consults the dead. Anyone who does these things is detestable to the Lord;"
---> Deuteronomy 18:9-13
*** This is because the same word which constitutes "poison" in both Hebrew and Greek", also refers to "witchcraft". PoisonIsEvil.
** In Catholicism, the work of scholars like Saint Augustine and Saint Thomas Aquinas led to the Just War doctrine, spelling out when it is acceptable for a good Christian to go to war and kill if necessary, and requires that both the cause and the conduct of a war be just.
* A belief in general non-violence that extends to all life is central to Buddhism, and this includes prohibiting the killing of any animal, human or otherwise. Certain sects, including Tibetan Buddhism, yield to practicality and [[WarriorMonk accept that sometimes it is necessary to defend oneself or one's nation]].
** The related Hinduism has similar beliefs, mostly grounded in the concept of reincarnation (as potentially any other animal), so it's thought that an animal you encounter could be a reincarnated ancestor.
* The Jains, the monks take the idea so seriously that they would walk while gently sweeping the ground before their feet with a broom so that they will not tread on any insects. They also wear a small mask on their face so that they would not accidentally inhale and kill a bug.
* In general, police forces in most civilized countries prioritize bringing people in alive as opposed to killing them. [[PoliceBrutality Sometimes, this doesn't happen.]] Most cops never even fire their weapon in anger, much less kill anyone. Some nations place such a high priority on non-lethal policing that their police officers don't even carry guns at all under normal circumstances.
** Note that this even applies to units like SWAT, despite the fact that they're the police equivalent of Special Forces. Like any other police officer, they are supposed to prioritize the ''saving'' of lives. However, this goes out the window should a suspect demonstrate the intent (threatening with clear intent to follow through) or action (they've shot at the officer or some such) of being a threat to themselves, the officer, or another human being - in which case, the officer may use lethal force.
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