The Challenge Season 21

Each Challenge pits numerous cast members from past seasons of Real World and Road Rules against each other (only the Fresh Meat Challenge has introduced new cast members that have never appeared on either The Real World or Road Rules), dividing them into two separate teams according to different criteria, such as by gender, which of the two shows they first appeared on, whether or not they're veterans or rookies on the show, etc. The two teams compete in numerous missions in order to win prizes and advance in the overall game.