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 was willing to kill in the first year of his existence, but as early as Batman #4 in 1940, he was declaring "We never kill with weapons of any kind." Because of this trope, Batman Grabs a Gun is an easy way to convey just how serious a threat a villain is.
Comics
- Final Crisis has finally shown us the only person so evil and dangerous Batman was willing to kill him: Darkseid. Which just makes the Superman example even funnier. By the time Batman kills Darkseid the villain has taken several levels in badass, and 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. It also helped Bats that he himself was going to die, so it was probably in his mind a fitting punishment for breaking his oath. Though it was ultimately revealed he was still alive.
- Flashpoint Batman 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 Secret Identity and was very close to him and his wife.
- In the Novelization of 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 "Eureka!" Moment when he realizes that he'd always loved the violence, despite what he told himself.
- This is sometimes used to explain why Batman is so adamant in his refusal to kill: he's afraid that he would come to enjoy the killing and become just another costumed serial killer.
- During an internal monologue, Gordon reveals he only tolerates Bats because he doesn't kill. The moment he crosses the line, according to Gordon, he'll be marked as a criminal like any other and his relationship with Gordon will be over.
- Cassandra Cain/Batgirl III 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 'the Batman rule' by other characters, specifically Batwoman and her father.
- He came very close to breaking his oath in Batman: No Man's Land. After the Joker murdered Gordon's wife, Batman still refused to kill him, but told Jim he would not stop him from doing so. (And Jim almost did, restraining himself only because there had been too much death already.)
- 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 Hoist by Their Own Petard situation, if he can, he'll save them, even villains as bad as The Joker.
- This is the basis of Jean-Paul Valley's tenure as Batman during 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 (which also leads to the death of Abattoir's current hostage) that everyone decides to shut him down.
- During 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 Ludicrous Gibs. After Bats leaves with Catwoman, Deadpool's head is mildly annoyed, chiefly because he has the munchies and Bats left before he could ask him to buy him chimichangas as consolation. - In fact, Batman hates to see anyone die. It's the crux of Kingdom Come when Superman tells him the one thing they both had in common was they saved people. Heck, in JLA/Avengers, while Plastic Man is amused by The Punisher killing drug dealers in a firefight, Batman immediately goes to beat the everliving crap out of Frank, to save said dealers.
- Batman: Legends of the Dark Knight explored this further, taking a more optimistic look at Bruce's philosophy. In Annual #1, after defeating the Joker Batman tells him that no matter how much he might want to kill him, it would be against everything he stood for as he believes in the absolute sacredness of human life above all else and that everyone has the capacity for change. This reinforced the end of The Killing Joke a few years prior, where Batman came close to redeeming him until he decided I've Come Too Far.
- Batman's rule sometimes goes into Stupid Good territory, like in a Judge Dredd crossover when he expressed sorrow for (seemingly) destroying the zombified monster Judge Death. Dredd has to remind him that they're not even alive to begin with.
- That said, during a later Batman/Dredd team-up where the Joker had joined the Dark Judges, Batman observed that the Joker had just made a great mistake in giving him an opponent that he could beat up as much as he wanted and know his enemy would survive, prompting Joker to flee back to his body to escape Batman's assault.
- The Dark Knight is called out on this in Batman: Under the Red Hood, in which Jason Todd asks "Why, on God's green earth, is he still alive?!"
- This was deconstructed in Detective Comics (Rebirth). To wit, Batwoman is forced to kill Clayface to save Cassandra Cain and Batman is furious. He calls in Dick, Jason, Tim, Damian, and Barbara to discuss this and possible punishments. While Dick and Tim side with Bruce, Jason and Barbara side with Kate. Jason accuses Bruce of playing to a double standard, though Barbara claims Bruce is scared of losing Kate as Kate is his last connection to his mother, Martha. Even more damning, he's afraid that if Martha knew of this, she would have sided with Kate, effectively killing any argument for his rule.
- In Batman (Chip Zdarsky), during Bruce's trip through the multiverse, he encounters various other versions of himself, including Batmen who did kill the Joker. Even those Batmen who only killed the Joker and nobody else make it clear that killing the clown ultimately didn't change Gotham for the better and just left them emotionally damaged, affirming to the Dark Knight that he's right to spare the clown's life even if he has to find another way to keep him contained for good.
- Batman's crossovers with Predator and Alien zig-zag this. In the Predator crossovers, Batman refused to kill the alien hunters despite them trying to kill him. This is mostly because they are intelligent and have a code of honor which he tries to use to his advantage. In the Alien crossovers, he's more than likely to kill them since they're animalistic.
- Discussed at various points in the Batman Vampire Elseworlds trilogy. In the first book, Batman kills at least three vampires directly in self-defence of himself and Alfred, lures the majority of them into a trap that he knows will be fatal, and ultimately sacrifices his human life to stake Dracula himself to save Gotham. Although he is a vampire himself in the second book, the Dark Knight freely kills other vampires, proclaiming at one point that they're "not even alive" so eliminating them from Gotham isn't killing even when one of them points out that he's a vampire himself now. Batman only considers himself as having crossed a line when he succumbs to the thirst for blood and drinks the Joker, which also leaves him vulnerable to crucifixes (prior to this the Joker had sprayed him in the face with holy water to no effect). He has Gordon and Alfred stake him to stop himself hurting anyone else, but the third book opens with Alfred removing the stake to restore his master and help Gotham face a new crime wave. Unfortunately, the months spent rotting in his coffin have left Batman consumed by his bloodlust, with the result that he goes around freely killing all of his old rogues. While his victims are all killers themselves, Gordon and Alfred each concede that the man they lost would have never killed, forcing them to ally with Two-Face and Killer Croc to stop Batman for good before he runs out of "deserving" prey and starts feeding on innocent people.
- Out of the Robins:
- Dick Grayson (Robin I/Nightwing) followed this rule to a T during his tenure as Robin and as Nightwing is normally a firm believer and follower of this rule, however he did beat the Joker to death in rage when taunted about Robin's death (he was revived immediately).
- Jason Todd (Robin II/Red Hood) kept to this rule save for one ambiguous interaction with a rapist who fell to his death until he returned from the dead and very much subverted it.
- Tim Drake (Robin III/Red Robin) has followed his mentor's rule, though at one point he set up a test for himself to see if he would kill his father's murderer by setting up a death trap for Captain Boomerang; in the end, he saved him.
- In Knightfall, Tim remains shaken by Abbatoir's death, saying he would never forget how he died in front of him thanks to Jean-Paul. Bruce approves sadly, telling him to never forget that feeling. Once he loses that feeling, he will have lost some part of his humanity.
- Stephanie Brown/Batgirl IV had trouble with this rule when she first started out as Spoiler but Tim Drake and her experiences as a crimefighter convinced her early on to adopt Batman's no killing policy.
- Damian Wayne (Robin V) was raised as a killer before he met his father and has some trouble with this rule initially during his tenure as Robin.
- Birds of Prey member 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 Batman doesn't trust her. Barbara Gordon, being more forgiving and willing to offer second chances, does trust her.
Films
- The Tim Burton Batman movies disregard this entirely, with Batman frequently killing both henchmen and the central villains (It's not like though he had any alternative in most cases). Doesn't stop him from flashing the most sadistic of smiles towards a strongman he'd just left holding a bomb.
- In The Dark Knight Trilogy Batman refuses to kill anyone, but he is generally more than happy to come scarily close to frighten someone, without actually crossing the line. This is demonstrated best during The Dark Knight.Salvatore Maroni: From this height, the fall wouldn't kill me.
Batman: I'm counting on it.- He does engage in some Loophole Abuse in Batman Begins, when he comments to Ra's al-Ghul that "I won't kill you... but I don't have to save you" before leaving him to his fate.
- He ultimately does end up breaking his rule, killing Two-Face in order to protect Gordon's son.
- In The Dark Knight Rises Batman has to break his rule again, due to the Big Bad carrying a bomb with only precious minutes before it blows up all of Gotham City. He also has to rely on his allies not abiding by his principle, as Bane would have killed Batman if Catwoman hadn't blasted him.
- Batman v Superman: Dawn of Justice zigzags the trope:
- After 20 years of activity, one dead Robin and the trauma of witnessing people getting killed during General Zod's invasion, Batman has been noted to have gone up a level in brutality. When chasing down some mercenaries smuggling kryptonite into Gotham, Batman shows no hesitation over gunning them down so he can take their cargo. Even after reforming, Batman still kills the rest of the mercenaries as they were holding Martha Kent hostage with instructions to execute her within the hour.
- It should be noted that unlike Batman's rogues' gallery, none of the people he killed were mentally ill, forced into a life of crime or run-of-the-mill thieves but contracted hitmen on Lex Luthor's payroll. Batman himself notes that he's got some "friends" in Arkham Asylum, four of his rogues' gallery appear in Suicide Squad (2016) (with Batman going easy on one and outright rescuing another) and Peacemaker (2022) mentions the Riddler and Mad Hatter are still alive, so presumably all of Batman's onscreen kills are just exceptions to his rule.
