WWE '13 runs on the engine dubbed, "Predator Technology 2.0", which succeeds the first version from WWE '12.[5] The engine has been updated to allow for more fluid animations, with odd collisions and transitions having been fixed and updated, it also allows over 300 new moves. Other past problems that have been fixed include a better weight detection system, contextual animations, and automatic attack homing, to ensure that the character always strikes toward opponents. The contextual animation system has been refined to ensure that it dynamically swaps out moves to make sure that the game is using the appropriate move animations at any given time and state. The weight detection system makes it so that small superstars such as Rey Mysterio are unable to lift larger wrestlers such as the Big Show. Thus, the contextual animations ensure that more appropriate attacks are put in the superstar's normal moveset.