Moments where a character warns an individual that if they kill the murderer, they will be just like him/her in Comic Books.
- Hugely averted in The Astounding Wolf-Man where Gary sets out to kill Zechariah for what the latter did to his life. When Gary finally gets the chance he takes it.
- This is why Batman does not kill criminals.
- This is invoked maybe half the times he goes up against The Joker. The comic book series also highlights the cost of Batman's decision: Joker's victims are estimated in the thousands, all of whom Batman is indirectly responsible for. Of course, it's debatable whether Batman is the one truly at fault, as opposed to Gotham's criminally negligent penal system.
- Seen in the Crisis Crossover Infinite Crisis, when he very nearly blows the head off of Lex Luthor's Alternate Universe doppelganger and (of course) relents. 15 years ago, he nearly did the same to '90s Anti-Hero The Reaper.
- In Knightfall, Dick Grayson (Nightwing), and Tim Drake (Robin), come upon Bruce Wayne just as he has apparently killed the mook who was attacking him. An outraged Nightwing declares: "killing this creep doesn't make you as bad as the slime we used to fight, it makes you worse, because THEY never stood for anything!" Of course, it turns out Bruce had used a move that makes the victim appear to be dead for a little while.
- In Under the Red Hood, Batman openly admits that he fantasizes about killing the Joker every single day, but won't because he believes that if he starts killing, he won't be able to stop. Used to justify why he hasn't taken out the Joker at the very least, given how the latter is utterly beyond redemption and has racked up a ridiculously substantial body count. But if it's okay for Batman to kill someone, it might be okay for Batman to kill anyone.
- In Death of the Family, the Joker pokes fun at this idea. Even he believes that Batman probably could kill the Joker without becoming anything like him. He taunts Batman and asks him what is the real reason Batman won't kill him. It's because Batman has a similar "delusion" as the Joker that his life follows a theory of narrative causality. Killing the Joker would simply force Gotham to send someone worse to challenge Batman.
- DC Rebirth complicates things; when Batman has a chance to sit on Metron's seat, granting him near omniscience, he asks the chair who is the Joker. Several issues and months later, Batman reveals to Hal Jordan what he learned: There is not one, but three Jokers.
- In at least one case this is a literal trope with Batman and Joker: One of the alternate Batmen from the Dark Multiverse killed his Joker. The moment he did so, Joker's heart released a special Joker Toxin that turns whoever kills him into the new Joker. Hence the Batman who Laughs, and a very good reason to not have Batman kill the Joker.
- Subverted in Birds of Prey #73, when Vixen thanks Huntress for "not giving in" and executing evil cult-leader Sovereign Brusaw, to which Huntress replies "Don't thank me... The truth is, my crossbow jammed."
- Played straight at the end of Batman/Huntress: Cry for Blood, when The Question begs Huntress not to kill Santo Casamento; she does it anyway.
- Captain America: In issue #245
◊, Cap tells a Holocaust survivor that killing the Nazi general who murdered her family and raped her would make her "just as bad". - Kremlin references the trope in Ex Machina Special #2 and states how he thinks such is an out of date, fairy tale ideal.
- Averted/Played with in Atomic Robo when A now elderly Skorzeny informs him that he was the one that killed Nikola Tesla, Robo's creator, during WWII, and he did it to steal the man's inventions to use against Robo, who was at the time serving in the US Army. Robo picks up a gun, aims... and then puts the gun away, informs the Nazi that he knows he's dying of cancer, and that he won't be dying like a soldier, instead dying alone, in a hospital bed, in agony.
- In Elseworld's Finest: Supergirl & Batgirl Batgirl gives Supergirl the speech when the latter wants to kill Lex Luthor. She even says: “Don't drop to his level, Kara”.
- Superman:
- Superman's long lived in fear of sliding down this slippery slope, and, in the Silver Age Alternate Continuity story Whatever Happened to the Man of Tomorrow?, it comes to pass when Superman, in order to save himself, his remaining friends, the world and possibly the entire universe, is forced to deliberately kill the villainous Mr. Mxyzptlk. While everyone else tries to convince him that his decision was clearly justified, he refuses to take the risk, cites this very reasoning as a condemnation of his actions, and so carries out a promise that if he should ever take a life, it would be the end of Superman. As it turns out, he fulfills his promise by stripping himself of his powers and living the rest of his life as an anonymous human, which actually gives him a happy ending after all.
- Averted in a Post-Crisis story arc when Superman is brought to an Alternate Universe where three Kryptonians, each more powerful than he is, released from the Phantom Zone end up killing all life on Earth. When they promise to find their way to Superman's universe and do the same thing, he feels he has no choice except, as the representative of justice on the planet, to execute them through kryptonite exposure. When he gets back home the next story arc has him suffering a Heroic BSoD as he deals with the choice he made. As he explains to the alien Cleric near the end of his self-imposed exile, he comes to realize he didn't have a choice: he wanted to Take a Third Option, but realized that no court on Earth would even try them and even if he could have, they would have broken free and destroyed that Earth as well.
- Spider-Man: Spider-Man does it often.
- In The Night Gwen Stacy Died, enraged over the Goblin killing Gwen, Spider-Man nearly beats him to death, but recoils because of this trope.
- Peter uses that argument while arguing with Clint Barton and the rest of the New Avengers that thinks about killing Norman Osborn, and not so long ago stopped Harry Osborn from killing his old man by saying, that if he'll do it, he will become exactly that kind of man his father always wanted him to be.
- Peter got one at the end of the Grim Hunt story, where he's shown a vision of the future if he kills the just-resurrected Kraven the Hunter. The reaction of the fandom was... unexpected, as the two page spread that encompassed the vision not only showed Peter apparently becoming a complete and utter badass, but featured the fan-favorite "Happy Birthday" costume. Cue the fans shouting "Kill the guy!" at their comic books.
- In Spider-Man Noir, this gets played interestingly because Spidey gets this lecture from Aunt May (who doesn't know his true identity) after he's already killed the Vulture - even though he was going to kill and eat her and she knew he did the same to her husband! During the lecture, Peter thinks to himself that she doesn't understand... but after she says she doesn't want to live in a world where men kill each other like animals, he realizes he's the one who didn't understand. He tries to live up to her expectations when he raids the Goblin's torture house, where he doesn't kill any of the Goblin's men except Kraven, and only in self-defense. He even refuses to kill the Goblin when given the chance, because he wants to see him properly brought to justice.
- Wolverine:
- Wolverine regularly tells younger, softer, less inclined characters to back off or stay outside before going in to finish off the bad guys. Normally, he states in some manner that only people who are going to do "what needs to be done" should go in. This is actually one of the reasons Wolverine is even included on some of the teams he's been on. For example during The Infinity Gauntlet affair Nick Fury explicitly states this is the reason for his inclusion "... because when it comes down to it, none of you are killers. He is." The same reason applies for why Fury brought the Hulk in as well.
- Played straight in one issue of Wolverine's self-titled comic, when confronting Reno and Molokai, hitmen who had murdered Jubilee's parents. Jubilee settles for a Groin Attack on both of them.Wolverine: Heck, they killed your parents. It's a good killin', ain't it? Ain't it?
Jubilee: You kill people! You've killed so many, and...
Wolverine: Yeah. You wanna sit up some night with me and talk to all of 'em? - Wolverine inverted the usual technique once when he defeated his old teacher, the Ninja Ogun, held him helpless, and called on Kitty Pryde to avenge herself on the man who kidnapped her, brainwashed her into nearly killing Wolverine, and tried to over-write her mind with a duplicate of his own. She grabbed a sword, charged, but in the end could not go through with what boiled down to outright murder... proving to all present that her soul remained her own.Kitty: It was very close. I wanted to so much — Logan, what if I had...?!
Wolverine: *wordlessly retracts his claws*
- In a later issue of Generation X, Jubilee learns that the grandfather of one of her classmates ordered the killing of her parents, and goes after him. The rest of the team go after her, prepared to cite this trope at her, when they discover that she never intended to kill the guy.Synch: We were afraid that, hanging with Wolverine, you would have wanted to...
Jubilee: You guys don't get it, do you? It's because of Wolverine that I won't kill. - Everyone's favorite many angled one, Shuma-Gorath, is immortal for this very reason — anyone who kills him will start to become a new Shuma-Gorath (unless they have a similar level of immortality). Doctor Strange took his own life rather than allow that to happen, which still didn't work. Fortunately an ally was able to purge Shuma's energies from Strange and bring him back.
- Lampshaded during Planet Hulk, when Miek kills the Imperial Headman who murdered his father in front of him, in view of the man's own children. The Headman notes that Miek is now just like him.
- The subject doesn't come up much in Sin City, although the series makes no qualms about presenting its Antiheroes as batshit insane in some cases.
- In Denny O'Neill's The Question, Vic Sage finally takes down the first arc's Big Bad, the corrupt Reverend Hatch, and explicitly invokes this Trope. "I could kill you... but then I'd be something just like you. Something vile. So I won't." He turns his back and walks away... Hatch draws a concealed weapon... and then Myra shoots Hatch in the back. "Maybe he wouldn't... but I will."
- Played with in issue #20 of The Transformers: More than Meets the Eye. Ratchet tries to give this speech to First Aid when the latter wants to go track down and kill one of the arc's villains, but the latter ain't buying it.Ratchet: No. If we kill him, we're no better than him. If we kill him, he wins.
First Aid: Yeah, except — we are better than him and he doesn't win. He doesn't anything. He's dead. That's the point. - In Uncanny Avengers Magneto kills the Red Skull, and Rogue responded by declaring that he's 'just like him'. For reference, Magneto is a mutant who survived the Holocaust, and recently lost his best friend, Charles Xavier. Red Skull is a Nazi who not only took part in the Holocaust, but has set up a new series of Concentration Camps for mutants and Inhumans on the grounds of Genosha, the sovereign nation Magneto previously controlled that was a safe-haven for mutants, and is keeping things in control using the stolen brain of Charles Xavier. He also had Magneto tortured for god-knows how long note . And, when he was briefly not attacking him, Red Skull began throwing taunts at him about how Xavier never cared about him and generally egging him on until Magneto crushed his head under a large rock. And yet, Rogue believes Magneto is just as bad as the Red Skull because he chose to kill him here. This is after, mind, Rogue had tried to kill Wanda (and would have succeeded if not for Time Travel) in a premeditated attack, and previously killed the Grim Reaper (albeit accidentally), while their team includes Wolverine (who has killed countless people, including his own son, and doesn't feel any guilt for them), Thor (who recently killed one of the Big Bads of the book), Captain America (who while he doesn't go out to kill, has killed in the past and previously fought in war, and is indirectly responsible for Red Skull's last death), and Scarlet Witch (who is not only directly responsible for the death of three Avengers (who all, fortunately, came back by this point, but still), but also responsible for the mutant Decimation, and thus indirectly responsible for all the depowered mutants who died as a result).
- Judge Dredd: Dredd accompanies academy trainee Cadet Giant on a mission to catch his mother's killer, a member of a group of VI-Zine dealers. He convinces the boy to arrest the perp instead of executing him by arguing that it would mean Giant's expulsion and lower him to the criminal's level. If a Judge kills (and they very often do), it's supposed purely professional and not for personal vengeance.
- Ultimate Marvel:
- Ultimate X Men:
- Jean says this to Wolverine when he's about to kill Wraith, the colonel from Weapon X who tortured him, if only because a Mutant killing a human will prove everything the media says about Mutants is right. Wolverine doesn't care, so she saves Wraith herself (though she does take the time to tell Wraith not to even think about thanking her). In the next arc, Wraith returns and abducts all the X-Men, Jean included.
- Jean doesn't approve killing the soldiers of Weapon X, even after the torture they put the X-Men through.
- Ultimate Daredevil & Elektra: Elektra threatens Trey, and leaves. She doesn't scare him. Rather, she prompts him to escalate the action.
- Ultimate X Men:
- A variant is seen in Empowered and the Soldier of Love, where even as Emp puts herself between the defeated Magical Girl burnout and Ninjette's blade she understands the main issue was what could have brought her friend out of a wish-fufillment induced happy-happy dreamland straight into a laser focused killing rage with no outside stimulus.
- Played painfully straight at the end of Tom King's Omega Men miniseries. As a vicious, bloody war rages for the control of the five worlds of the Vega system, Kyle Rayner and the Omega Men finally confront the Viceroy of the Citadel in his chambers. Kyle prevents Scrapps from killing him, saying that they need to show that they're better than the Viceroy. Unfortunately, Princess Kalista kills him anyway, leading to the Omega Men becoming the new brutal rulers of the five worlds.
