Euphoria (Engine)

Created by NaturalMotion, Euphoria is a game engine that creates animation "on the fly" by using a skeletal-muscle system and a collision model, the AI that controls this "ragdoll" is aware of his surroundings and has an underlying sense of self-preservation. Used by Rockstar Games in their games (Eg. Grand Theft Auto IV, Red Dead Redemption, Max Payne 3.) Every reaction is different as it runs on a GPU instead of premade animations, characters will grab their wounds if shot, try to shield themselves from oncoming projectiles or walls, try and find a comfortable position when on the floor, grab things and other people and flail when falling.

Person 1: "Wow this euphoria (Engine) is great!"
Person 2: "I know! Why dont more companies use it!"
Person 1: "Too expensive."