Why do we play games? And why do some gamers feel compelled to achievement hunt until they collect everything? Game Theory teams up with Jirard and Greg from "The Completionist" to unlock what compels us to play games, why video games are addictive, and the psychology behind achievement hunters. Game Theory, part of the Game Theorist network. Check out all our shows: Game Theory:    • Game Theory: The Complete Series   Game Exchange:    • Game Exchange   Digressing and Sidequesting (DSNQ):    • Digressing and Sidequesting