Any casual fan of comic books probably knows that, as a general rule, comic book superheroes don’t kill. Well, except for all the times that superheroes killed people. But as a general rule. Superman doesn’t kill, Spider-Man wouldn’t think of it, and Batman won’t even look at a gun. Lethal vigilantes like The Punisher and Wolverine are notable specifically because they’re the exception to the “no killing” rule. For the most part, superheroes generally try to find a better way than simply slaughtering their opponents. Sure, Captain America killed Nazis in the war, but that was different. They were Nazis.
That being said, many heroes have been known to treat this fatality-free philosophy like most people treat their diets; with a lot of bold talk, questionable commitment, and frequent “cheat” days. Except instead of eating a whole pizza, these superheroes commit mass murder. Comic book protagonists find themselves killing as a last resort, for the greater good, to avenge a personal wrong, or just because they’re having a really bad day.
This supposed moral code is abandoned more often than Kryptonian children, making it more of a guideline than anything. In fact, superheroes now break from tradition in myriad ways, including brutally killing their own friends, allies, and teammates. So, maybe we should call it a “rough guideline,” rather than a set rule.
The Injustice comic book series, along with the video games, are about an alternate reality where Superman breaks bad and becomes the dictator of the world. This is precipitated by the death of Lois Lane and most of Metropolis in a scheme by the Joker, which leads to Superman punching a hole in Joker’s chest. The slaughter doesn’t stop there.
Superman gets darker and darker, and several of his former teammates are forced to oppose him. One such hero, Green Arrow, is brutally beaten to death by Superman right in front of Ma and Pa Kent. It was easily one of the darkest moments of the entire series.see more on Superman
Fox adapted the Old Man Logan storyline for their film Logan, but they changed one of the most shocking aspects of the story. Old Man Logan features a Wolverine who has sworn off violence and refuses to pop his claws ever again.
Eventually, the reader learns that his newfound pacifism is due to a horrific plot that saw Mysterio and others convince Wolverine that his teammates were supervillains attacking the X-mansion. The illusion led Wolverine to slaughter them all. Even Jubilee, and everyone forgets about Jubilee.see more on Wolverine
Most deaths involving superheroes (and their associates) are quite violent, but this one is just sad. The first superhero Civil War claimed many lives, but it left Tony Stark’s long-time bodyguard, chauffeur, and friend Happy Hogan in a coma after attempting to thwart a strike against Stark.
Hogan, who was married to Pepper Potts at the time, was essentially brain-dead, and Pepper struggled with what to do. Tony Stark decided to take matters into his own hands. He turned off Happy’s life support with his Iron Man tech, preventing Pepper from having to make a tough decision.see more on Iron Man
Superheroes are known to go through ups and downs, but Hal Jordan (the most famous Green Lantern) took that to the extreme in Emerald Twilight. Hal saw his hometown, Coast City, destroyed and he completely snapped.
He became obsessed with the idea of recreating his city with the power of the Green Lantern Corps’ central battery, and he was willing to kill to get it. Hal snapped Sinestro’s neck and slaughtered countless fellow Corps members. Worst of all, he killed everyone's favorite non-human Green Lantern, Kilowog.see more on Hal Jordan