The American reality game show "The Challenge" was originally known as which TV show?

"The Challenge" was originally known as "Road Rules: All Stars". It is a reality game show on MTV that is spun off from the network's two reality shows, "The Real World" and "Road Rules". The contestants compete against one another in various extreme challenges to avoid elimination and win a cash prize. "The Challenge" is currently hosted by T. J. Lavin.

Since the 4th season, each season has supplied the show with a unique subtitle, such as "Rivals". Each season consists of a format and theme whereby the subtitle is derived.