MIT lecturers Philip B. Tan and Jason Begy lead this session from CMS.608 Game Design, examining how game designers understand player motivation. The class works through Richard Bartle's classic taxonomy from his 1996 essay on MUD players, which maps motivation along two axes: interest in the game world versus interest in fellow players, and desire for knowledge versus desire for proficiency. Tan and Begy walk through the resulting player types, achievers, explorers, socializers, and killers, and discuss how different game mechanics reward or encourage each style of play. Students debate the taxonomy's usefulness and limitations as a design tool, then attempt to build their own alternative frameworks for categorizing player behavior. The discussion draws on an assigned chapter from Brathwaite and Schreiber's Challenges for Game Designers, grounding the theory in practical exercises for designing toward varied player types.