Murder is the bread and butter of most video games. While there are of course great non-violent titles that have achieved huge success, shooters and action games still dominate the market, and that means players will do a lot of killing over their gaming career.
Of course, developers have ways of making sure you're only killing the people who truly deserve it - whether that's a monster trying to eat your face off or something else entirely. In fact it's standard that if you try to shoot your squad mates in Call of Duty, say, the game will hit you with a fail state and punish you for friendly fire.
More imaginative developers, though, find inventive ways to punish players for killing, with unique game overs or even unique set-pieces.
These scenarios can be used to drive home a narrative point through the mechanics, keep you role-playing as a character with a specific personality or more flippantly break the fourth wall and directly address the player. No matter the reasoning though, each one makes you think twice about pulling the trigger on another unsuspecting NPC.
10. A Demonic Visage - Metal Gear Solid V: The Phantom Pain
The Metal Gear solid franchise has always had a few tricks up its sleeve when it comes to telling players off for giving in to their more bloodthirsty impulses. So, with this entry you get two for the price of one.
The first genius punishment for leaving a trail of bodies in your wake comes in Metal Gear Solid 3, a game which, well, literally confronts you with that trail of bodies. In this beloved Big Boss prequel you encounter The Sorrow late in the game, a supernatural character who haunts you on a long trek through the spirit world. Here you're confronted by the souls of the people you've killed, who show up as ghostly figures. If you've been trigger happy previously, this can turn into on laborious sequence.
MGS V similarly punishes players for killing people by awarding them with Demon Points. The more kills you rack up, the more demonic playable character Venom Snake becomes. I mean this literally, as the devil horn on your head (in-lore this is a bit of lodged shrapnel) grows with the amount of evil actions accomplished.