The idea that Batman doesn't kill people, and the secondary idea that Batman doesn't use guns, is usually seen as sacrosanct within the fandom.
He doesn't kill. He doesn't pick up a gun and use it. He has gun-like weapons, but nothing you could ever grab for yourself down at Ammu-Nation.
But let's be real:kills people. The character has long moved into a less "comic book" version of reality and into a more "realistic" take on the world, and that move means that it's impossible to ignore the piles of bodies he leaves in his wake. Batman kills people left and right. The important thing is that they die out of frame.
There's a difference?
Of course there is, especially in the heightened reality of games and comics. This is why certain video games can literally bring a planet down on the head of a character and they can be healed with a potion, but being stabbed during a cut scene is forever. Batman has always killed people, the "camera" just never sticks around to see the aftermath.
If it ever did, it would be impossible to ignore how silly the no-killing rule has become in modern Batman lore.
Gamesradar+ posted a pretty funny article recently where a medical doctor talks about what would actually happen were Batman to do the things we see him do in Arkham Knight. Surprise! A lot of people would die.
"As with any vehicle collisions, crush injuries to the victim can occur. This is when the body is caught between two objects being pushed together by a high pressure. These type of injuries are responsible for broken bones, severe bruising, bleeding and compartment syndrome," Dr. Hussain says in one section.
It gets even sillier.
One of the Batmobile’s jazzier features is the immobiliser, a rocket that explodes on impact but not enough to kill whoever is driving it’s intended target. Or at least that’s what Batman should keep telling himself. Dr. Hussain says "[They’re] unlikely to survive this trauma. The impact of the rocket will cause damage, but more than this the resulting explosion would cause extensive burn injuries."
This is an interesting look at the issue, but you don't really need a doctor to tell you that if a dude dressed like a bat fires a rocket at someone, that person is likely going to die. If you get run over by a tank, you die. If you get beaten by a baseball bat until you lose consciousness, you die.
There are other stories in the comics where Batman kills, even after the character was locked down in terms of themes and "rules." Comics Alliance writer Chris Sims once wrote a long piece on this very issue, bringing up the work of Mike W. Barr.
"Again, he’s one of my favorites — 'Fear For Sale' is one of the best Batman stories ever, and I recently listed 'The Doomsday Book' from Detective #572 as an underrated classic," Sims explained.
"Unfortunately, not only does Batman use a thug as a human shield in that story ...he also wrote a story called 'Messiah of the Crimson Sun' where Batman just straight up kills Ra’s al-Ghul, and then when Robin points this out, he responds with 'Did I, Robin? Did I?' Yes, Batman. Yes, you did. You used a remote control to override his spaceship controls and flew him into a giant laser beam, then opened the hatch so that his ashes were blown out into the vacuum of space."
Sims is desperate to cling to the idea that Batman doesn't kill, despite the fact that Batman kills people.
"For me, though, both of those things fall squarely into the category of Plot Points I Completely Ignore, because as far as I’m concerned, 'Batman Does Not Kill' is one constant, immutable traits of the character, as much an inherent and necessary part of him as anything else," Sims wrote.
So Batman kills, but we're supposed to ignore that fact in order to believe in the golden rule. The whole article is interesting if you're a Batman fan, and gives more nuance to the arguments, but the point remains that Batman kills. Arkham Knight, just like the recent Netflix version of Daredevil, uses these circumstances and characters as a way to legitimize both torture and murder.
They're both enjoyable pieces of entertainment, but you have to perform some intense mental gymnastics to pretend that while the text may say that Batman doesn't kill or that all these thugs survive, you are beating people to death with your hands while also shooting guns from your tank at them.
This isn't critical of Arkham Knight; believing in any set rule of comics is a one-way ticket to frustration and in the circumstances of the game Batman is under the impression that getting out the tank and killing a shit-ton of people is justified. There's an interesting conversation to be had there, but let's not ignore the fact the game has you killing as many people as most action games on the market.
The fact that Batman media wants to have the player or viewer take tacit or direct part in these killings while patting them on the back and saying it's all OK because Batman doesn't kill isn't just silly, it's a bit insulting.
We're dealing with decades and decades of comics history, of course we're going to find instances where Batman kills people, and the games are filled with characters who would never survive their encounter with Batman.
In some ways it makes the character more interesting, not less; this isn't a criticism of those pieces of entertainment but more a look at Batman in the whole. He kills. The longer we tries to pretend he doesn't, the sillier the whole thing becomes.
We want a world where our heroic avatar is both righteous but also willing to kill anyone in his way in the name of justice. We want the violence without the blood on our hands. Until we resolve that issue we're stuck with a character who is comfortable causing the death of others as long as he doesn't have to watch.