 The player him/herself is entirely in control of which level they use; once the player has locked onto an enemy, the lock-on reticule changes color over time to indicate the level; white (level 1), yellow (level 2), and, finally, red (level 3).As an example, in the first game, if using the plastic bag, a level 1 kill involves the player simply using the bag to suffocate the enemy.A level 2 kill involves him placing the bag over the enemy's head and kneeing them repeatedly in the face.