Comic Books

• Batman
• Superman

• Black Canary: As with all good heroes, Dinah is an idealist who believes strongly in not killing her enemies. Interestingly, she doesn't force this ideal onto others, and happily tolerates working with Huntress and Shiva (though in the latter case, she doesn't stand much choice). For her sake, the two even tend to hold back the lethal force when its not required, too.
• In 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.
• The Flash:
  • When Barry thought he killed Godspeed, whom he'd been insisting that real heroes never kill:
    The Flash: (depressed) Heroes don't kill. We find a better way.
  • Much like with Superman and Batman themselves, both Barry and Wally decided this rule no applied to Darkseid in Final Crisis and led the Black Race to Darkseid in the hope he'd kill him.
• Green Arrow (Oliver Queen) 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. He made an exception for Prometheus after the latter attacked Star City with a Kill Sat 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.
• Green Lantern:
  • The Green Lantern Corps used to follow this policy. The Guardians revoked it during the Sinestro Corps War. 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; Space Police shouldn't be any different (mind you, this was in 2007; well before police shootings came under increased scrutiny). The next few issues after the event explored the morality of giving the Lanterns this authority. 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 they're in agreement that killing is a serious matter, and needless murder is right out.)
  • Well before the Lanterns were given authorization, there was a subversion in the case of '90s Anti-Hero Jack T. Chance. When he discovered his ring would not let him use lethal force, 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 Crapsack World — before Jack, Lanterns patrolling that planet would be offed on a regular basis.
• Injustice: Gods Among Us: This and Pay Evil unto Evil are deconstructed and become a point of contention between the Regime and the Insurgency. In an alternate dimension, The Joker tricks Superman into killing his own wife and nuking Metropolis. Enraged, Big Blue kills the clown in revenge and most of the Justice League becomes hellbent on eliminating crime at all costs. Batman disapproves of the Regime's hardline stance and actively opposes their efforts, but can't refute Superman's points about criminals like Joker breaking out of Cardboard Prisons repeatedly to menace society with no impunity. The entire mess could have been avoided if Joker was locked up in a more secure facility with no chance to escape rather than Arkham, which is known for its Swiss-Cheese Security and inability to rehabilitate repeat offenders. On the flip side, Batman points out that repeatedly killing for justice has turned the Justice League into worse monsters and that their initial motive to end crime, while well-intentioned, has morphed into a twisted and selfish desire to oppress the Earth.
• Invoked to an almost headache-inducing degree in the early 2000s run of Justice Society of America. Black Adam, 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 U.S. 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.
• In the long running independent superhero comic book, 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.
• 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.
• Traditionally Wonder Woman was always the most compassionate and most opposed to killing of DC's big heroes, Bats and Supes have always been more accommodating to those with the legal authority to using lethal force even if they themselves avoid it while Diana is more likely to argue against it. This has varied over the years, and modern writers often posit her as the member of the Big Three without any compunctions about killing:
  • Wonder Woman (1942): To be an Amazon in the Golden Age one had to take an oath no never take a human life, and breaking this oath not only ensured one was no longer an Amazon and their limited immortality was revoked but also invited Aphrodite's wrath which generally meant the oath breaker was stuck in a mind controlling Venus Girdle indefinitely. Given how many non humans run about in comics there was a rather large loophole, one Diana was not eager to exploit.
  • The Post-Crisis version of Wonder Woman 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 god Deimos in order to help her friends in peril. Notably at this point it was unclear if the gods retained their Resurrective Immortality from the previous continuity.
  • In the crossover prelude to Infinite Crisis, Wonder Woman 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 Blue Beetle, 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 Kingdom Come was the climax of her Heroic Breakdown during the miniseries, and earned her a What the Hell, Hero? from 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. 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. The historical reputation of the Amazons as killers rather than peacemakers also helped with the ease of this transition.
  • Sensation Comics Featuring Wonder Woman: "Generations" includes a flashback in which a very young Diana is taught the Amazon's law of avoiding killing opponents if at all feasible, even when it endangers themselves.
  • The Legend of Wonder Woman (2016) brings Diana closer to her traditional viewpoint on this matter. She understands that soldiers kill but she herself will not even in the middle of a battle. It helps that the Duke of Deception's zombies give up the ghost upon being lassoed with the lasso of truth as whatever is animating them cannot stand the truth of their situation, which she does not see as killing them as they are not alive. While she does "kill" the Titan it is another being animated and run by spirits that are no longer housed in their original bodies and that have been twisted by being congealed together and "living" for so long.

Films

• Surprisingly averted in The Adventures of Captain Marvel, 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 a two fisted pulp adventurer than a traditional superhero it makes sense, and he does spare the lives of most of the villains he faces.
• DC Extended Universe
  • Deconstructed^note Along with many other tropes, superhero-based or otherwise in Man of Steel, where Superman is placed in an impossible situation where, 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 Phantom Zone — just Kal, Zod, and a family of four about to be incinerated by Zod's rampage...so he breaks Zod's neck. This is not an action he undertakes lightly however, as the following scene shows. Expanding on this, Word of God says that in the Man of Steel continuity, 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.
  • Also averted in Batman v Superman: Dawn of Justice where Supes kills Doomsday as part of his Heroic Sacrifice, though like the Zod example there was admittedly little choice in the matter with Doomsday being a massive and nigh-unstoppable threat to Earth. Also in all fairness Superman killed Doomsday in the comic as well, the only difference being it wasn't permanent in the comics due to Doomsday having Resurrective Immortality.
    • Batman as one would expect for a Darker and Edgier director like Zack Snyder, the Dark Knight in Batman V Superman Dawn Of Justice is shown both killing mooks indiscriminately and even using firearms. There is some level of justification as this Batman in particular is jaded past the point of a Despair Event Horizon after the death of Robin and Wayne manor getting burned down. DCEU Batman only plays this straight in regards to Superman as Clark's words about Martha put an end to his determination to murder Supes and Batman also spares Lex Luthor at the end, although there's Fridge Logic with the latter as DCEU Batman has no qualms about killing henchmen just doing their jobs and yet shows mercy to Lex as well as Joker who are both unrepentant psychopaths. Then again you can argue it is pretty justified given the henchmen Batman kills in this movie are all heavily-armed international mercenaries who are in the business of doing things like massacring entire villages - in both threat level and repugnance they're quite a few steps above Gotham's street criminals.
  • Played straight in Justice League (2017) as Superman, while he does beat the piss out of Steppenwolf as a change of pace he doesn't kill him, with Steppenwolf Boom Tubing away with the Parademons. In Zack Snyder's Justice League meanwhile, Supes may not kill Steppenwolf himself, but he does certainly contribute to Aquaman and Wonder Woman putting him down.
  • Averted in Wonder Woman (2017) where the titular heroine with single exception of Doctor Poison is shown killing many German soldiers, Ludendorff and Ares. This likely due to taking ques from the modern Darker and Edgier incarnations of Diana whom ever since murdering Maxwell Lord has been depicted as a superhero unafraid to use lethal force. In Zack Snyder's Justice League she not only kills the black clad criminals (whose leader admittedly was about to shoot a bunch of children) but beheads Steppenwolf herself with the help of Superman and Aquaman.
    • Played Straight in the Lighter and Softer Wonder Woman 1984 as Wondy doesn't have her sword and notable doesn't kill either of the villains (albeit Cheetah almost getting drowned and electrocuted in the climax). Although a few of henchmen driving trucks in the Egypt convoy Chase Fight aren't so lucky and are killed by Diana.
  • Zigzagged in Aquaman. Arthur doesn't like killing and mainly just beats the crap out of the Atlantean soldiers rather outright murdering them and spares his brother Orm the Big Bad in the climax, but he refuses to Save the Villain when Black Manta's father Jesse Kane is trapped underneath a torpedo despite the former's pleading. Although given Kane had just tried to kill Arthur even after he'd shown mercy and had killed many innocent people up to that point (as Arthur also points out) he had it coming.
  Aquaman: Ask the sea for mercy.
  • Played Straight in SHAZAM! (2019) unlike other DCEU films and the aforementioned original Captain Marvel film as Billy and the rest his siblings show mercy to the Big Bad Doctor Sivana and after depowering him, Billy saves his life as he falls from the sky and he goes to jail rather then ending up dead.

Live-Action TV

• Arrowverse
  • Arrow
    • After five or so years of semi-righteous murder left and right, Oliver Queen attempts to do his vigilante work with less collateral damage (barring that of property, of course) after Tommy's death. However, this trope is danced around, as he instinctively puts three arrows in Count Vertigo when the latter grinningly threatens Felicity. And all this mere weeks after the vow is made, too. His resolve is nowhere near as strong as that of his counterparts.
    Oliver: [on choosing to kill the Count] Felicity... he had you and he was gonna hurt you. There was no choice to make.
    • Since then, he mostly keeps to the rule, only killing when absolutely necessary. What causes him to actually backslide is Laurel's death in Season 4. Not only does he kill her murderer Damien Darkh, he almost discards the rule entirely, only going back to his previous provision of killing when necessary after a talk with Thea and the Trauma Conga Line that is the latter half of Season 5.
  • In The Flash (2014), 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. This is mostly out of pragmatism rather than any kind of morality, as he finds the consequences of murder more trouble than they're usually worth. After Flash challenges him to continue his supervillain career without killing anyone, he accepts, seeing it as a true test of his skills.
  • Supergirl: Supergirl follows the same general "Thou Shalt Not Kill" policy as her cousin, which has led to a few baddies escaping. That does not mean she has not had to destroy a few alien baddies from time to time, and she also destroys the Red Tornado in a fit of anger, not realizing that he'd become sentient a few moments before. The rule is decidedly not followed by her DEO colleagues, including her sister, Alex, who is a trained killer and uses such skills on more than one occasion. The Guardian, although he delivers Daredevil-style beatdowns on bad guys, also adheres to Supergirl's no-killing rule.
  • Batwoman (2019) largely sticks to this principle until her sister Alice reveals to Kate Kane that the villain she has hostage (who had held Alice prisoner for years) kept their mother's severed head in his fridge to provide skin to give his own mother a facelift. Then she kills him with her bare hands. However she realises the dangers of the dark path after meeting an alternate universe version of her cousin Bruce Wayne who had started killing his villain's gallery and evolved into a psycho vigilante, killing his world's Superman.
• Since it is a Batman prequel series, it's no surprise that Gotham invokes this. In the final episode of Season 3, Bruce Wayne outright declares it after defeating Jerome Valeska, saying that will keep him from becoming a villain himself. It's arguable, though, that if Bruce ''had'' decided to kill the villains, he'd spare himself- and the city- the future troubles he'd get into.
• Peacemaker (2022): Discussed, and ultimately rejected, by the eponymous Anti-Hero. When someone asks Peacemaker why he doesn't have a Rogues Gallery like the more traditional DC Extended Universe superheroes he shares a world with, Peacemaker points out he kills his enemies so they can't commit any more murders. Then he demands to know how many Batman has indirectly killed by putting people in Arkham so they can escape and kill again. The other guy has no comeback.
• In Smallville, Clark Kent refuses to kill enemies, but he does not consider Karmic Death or accidental death to be murder. The one time he attacked an opponent (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. Oliver 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.
  Chloe: This is murder.
  Oliver: This is justice.
  • Clark also doesn't hesitate to kill Brainiac, justifying it with the lame technicality that Brainiac 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.
• Wonder Woman (1975): Wonder Woman declares in the pilot, "The New Original Wonder Woman", "Where I'm from we try never to hurt people". Aside from a couple of war-related incidents and an encounter with Hitler in "Anschluss 77", Wonder Woman's opponents are generally let off very lightly, especially considering what she is capable of. She'd often let the hired thugs simply go since they're no threat.

Video Games

• Injustice: Deconstructed in both Injustice: Gods Among Us and Injustice 2. Batman thinks killing in the name of justice would make him no different from the criminals he or the Justice League frequently deal with but wasn't able to end The Joker's Karma Houdini problem, which backfired horribly when the Monster Clown killed millions in Metropolis in a scheme to drive Superman to a Face–Heel Turn. He insists on applying this rule out of his own ego even when he's outclassed by the likes of Darkseid or Brainiac, but can't respond when the Regime members all but accuse him of Murder by Inaction by asking how many innocents must die before realizing his no-kill rule is ineffective and that Murder Is the Best Solution, or how his misplaced leniency has caused villains like Gorilla Grodd to keep on breaking out of Cardboard Prisons like Arkham and terrorize society with no impunity, despite knowing they won't reform no matter how many chances they're offered, as it only worsens their behavior. Believing traditional superheroics to be outdated, the Regime remnants see Batman's refusal to kill as a sign of weakness and think the ethical framework that lets criminals alive is too ineffectual. They also call him a hypocrite, in that while he won't kill, traumatic brain knock-outs are fine, but he never finds out if they survived said injuries.
• In Mortal Kombat vs. DC Universe, to keep with their credo, the heroes of the DC universe get "Heroic Brutalities" instead of Fatalities, moves that punish the enemy without killing them... or so it's supposed to be. In practice, 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.

Western Animation

• DC Animated Universe
  • Batman: The Animated Series: Much like the rest of the franchise, Bruce Wayne enforces this trope, though there are times when he comes dangerously close to breaking this rule.
    • 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, furious about this, corners him at the end of the episode. He saves him from an incoming train. When the Sewer King hysterically asks why, Batman angrily responses that although he realizes that passing judgment is a matter for the courts, he was 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 Kill All Humans follows his human template's example all too well. The robot has a Heroic BSoD 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.
  • Batman Beyond:
    • Terry McGinnis seems to have an attitude somewhat similar to the Batman Begins 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 combat pragmatism such as chucking handy barrels of toxic waste.
    • In "Sentries of the Last Cosmos", Simon Harper tricks three fans of the titular video game into thinking it is real and equips them with weapons and armor based on the game, telling them to destroy his enemies. He is infuriated when they capture Eldon Michaels instead of killing him. They remind him that the code of the Sentries forbids them from killing in cold blood. Simon then tries to kill Eldon himself before Batman interferes.
  • In Justice League, 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 had to persuade him from killing Darkseid that time though.
    • The League doesn't seem to adhere to this rule under wartime conditions. In "The Savage Time", every member of the Justice League present commits clearly lethal actions in battle against the Nazis, and with the Green Lantern ring out of commission, John uses an ordinary rifle like any other Marine. Similarly, in the pilot, nobody bats an eye at killing Imperium aliens, and when fighting Thanagarians, the League are willing to use deadly force as well.
    • In the episode "Epilogue", we learn in a flashback that because the Psychic Powers of Ace of the Justice League Royal Flush Gang have evolved, she was going to die of a brain aneurysm within days or even hours, and the psychic backlash would kill anyone within miles! Thus Amanda Waller gave a device to kill Ace before she took others with her. Shayera would have taken the device but Batman volunteered to do so — and when he found Ace, sure enough, he had no intention of using the device. Instead, he convinced her to fix everything by staying with her at her request and holding her hand before she died peacefully.
    • In the series finale Destroyer, 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 convince him otherwise. According to Word of God, Superman was actually right this time. Darkseid and Luthor both became part of the Source Wall.
• In the 1960s cartoon The New Adventures of Superman, Superman (yes, Superman) kills his opponents at least twice, although they might fall under What Measure Is a Non-Human?: The first is when he causes a group of possibly sapient "lava men" to revert to being just ordinary lava, and the second is 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.
• In Teen Titans: Trouble in Tokyo Robin gets in some trouble with the law when it looks like he killed the supervillain he was fighting. In the series itself, however, the episode "Aftershock" 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 Terra decides to pull a Heel–Face Turn and stops working for the villain Slade; she accomplishes this by throwing Slade into a pit of lava.