In
X-Men,
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 Wolverine carving people up on the six o'clock news, so you'd better stifle any
Darker and Edgier tendencies,
especially while wearing an X. However, it's not as absolute as it is with Batman or Superman, as individual members can fall anywhere from
The Cape to
'90s Anti-Hero, and most X-teams will defend themselves or others lethally if it's
the only way. A few of their main villains also have
Joker Immunity. This policy has changed in recent times and the X-Men are more open to killing.
- 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. Interestingly, during Inferno, their positions were switched when Cyclops called out Storm for killing the demon N'astyhr.
- Wolverine is one of the most glaring subversions in comic books as he won't hesitate to cross the line so threats can be put down and he will go so far as to hunt down those who have done horrific things even long after the fact. His own views on the subject lean towards Pragmatic Hero — he doesn't want cutting people up to be his first response, but equally, he's not going to wait for a clear threat to make the first move. In one comic he tells Kitty he's never killed anyone who hadn't attacked first, or clearly and unequivocally demonstrated their intention to kill him, innocents or people he cared about. Unfortunately, thanks to be a natural berserker, this is occasionally harder for him.
- In the Chris Claremont era, Storm was the only character to have an iron-clad policy of not killing anybody, which caused consternation among her teammates when she abandoned it for a more pragmatic attitude to go with her new punk look. After her punk phase and into the present-day, Storm has taken a moderate view; she prefers not to kill, but if it's the only way to stop a villain, she won't hesitate.
- Colossus, the most good-hearted of the team, was also very against killing enemies, to the point where the times he does kill someone either means they've crossed the Godzilla Threshold or someone's gotten the generally sweet-natured guy genuinely mad. Notably, he killed Moira McTaggart's psychopathic, god-like son Proteus because there was no other way to stop him and he was the only one who could. And during the Mutant Massacre story, after the Marauder Riptide talks about how he enjoyed murdering innocent mutants and nearly kills Nightcrawler, Pete walked through his attack and broke his neck one-handed.
- Cable 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 a good partner. The other guy was Deadpool.
- A move towards this has actually become one of the significant driving arcs for X-23: She was bred and trained from birth to be the perfect assassin, and even after first joining the X-Men she was a ruthless killer who may have been even more efficient at it than Wolverine, with Matthew Risman telling her she was "bred for murder." However X herself hated what she was, and has increasingly tried to avoid resorting to lethal force. By the time of All-New Wolverine she has sworn off killing entirely. She does make a very specific exception for Kimura, the woman who tortured and brainwashed her into a living weapon in the first place. Knowing that Kimura will never change and will always view her as property, Laura proceeds to drown her.
- By the time of Dawn of X, they have clear rules over what they can and can't do: mutants killing mutants? Fine (Because they have access to reliable resurrection tech). Mutants killing humans? Nope. Note that their ruling body can make case-by-case exceptions to the rule, and X-Force, the mutant black ops team, has a blanket exemption due to the extreme nastiness of their typical opponents. All of this goes out the window after the 2023 Hellfire Gala.
