This chapter is about tearing motions apart and reusing them. For example, suppose that a game character has 50 different walking motions and 30 of the 50 motions have identical lower body motions but different upper body motions. To minimize the data size and the memory that are required to play the game, the 30 motions can be divided into the upper body motions and the lower body motions. Having one lower body motion (i.e., walking) shared by the 30 different upper body motions (e.g., reloading a rifle, pulling a trigger, and throwing a grenade), only one lower body motion is necessary for the 30 walking motions.