Batman doesn’t kill. Well not for awhile at least. He did have a brief “anti-hero” stage where he carried a gun and killed as he saw fit. That’s long past though. It’s not the 80s anymore. He’s “strictly” non-lethal in Nolan’s Bat trilogy and in the Arkham Asylum and Arkham City videogames.
Except not really. Let’s ignore the all the bat bashing, bat rockets, and bat hits in Nolan’s trilogy along with the very morally questionable “I don’t have to save you” and focus on the Arkham games. Throughout the games you hang baddies upside down from gargoyles, knock them senseless with your bare fists, and choke them out. All of which results in an unconscious baddie. These would often be fatalities in real-life, but not in Batman’s world.
The game also rewards you for tossing enemies off high ledges. They are presumably knocked unconscious by the four story fall into the hard ground. This is a “Bat-Kill” — Batman didn’t kill them. Gravity and the ground did. Batman is innocent.
Bat-Kills are really common in other media as well. Take Home Alone for instance. Do you really think those guys survived? The worst offender may be the cartoon series Avatar: The Last Airbender. In the last few episodes they deeply ponder killing the final villain. Meanwhile, they have been throwing rocks and fire at opponents, knocking them off tall walls and ladders and they seriously believe no one has been killed. It’s just a tad-bit on the ridiculous side.