The first season of The Challenge: All Stars premiered on Paramount+ on April 1, 2021. The season featured twenty-two cast members from The Real World, Road Rules and The Challenge competing for $500,000.
Contestants
Casting
Several potential cast members were asked to appear with some being chosen as alternates and flown out to Argentina for the entirety of production. Alternates included Casey Cooper & Ryan Kehoe of the Fresh Meat season of The Challenge, Sophia Pasquis from Road Rules: The Quest, Heather Cooke from 2011's The Real World: Las Vegas, and Cohutta Grindstaff of The Real World: Sydney.
Format
All Stars features a daily challenge, nomination process and an elimination round. Daily Challenge: Players compete in the main challenge either individually or in teams. For team challenges, teams elect a male and female captain before the challenge begins. The winning player (for individual challenges), or winning team captain (for team challenges) of the designated gender is immune from elimination while the respective losing captain or player of the designated gender is automatically sent into the elimination round. Nominations: Players besides the captains of the winning and losing teams (for team challenges), or both individual winners and the last-place player (for individual challenges), participate in nominations to select a second player of the designated gender to compete in the elimination round. They are given a chance to discuss the nominations before voting in an open vote. The player who receives the most votes will participate in the elimination round. Eliminations (The Arena): The nominated player participates in an elimination round against the same-gender captain of the losing team, or the last place player from the daily challenge depending on the structure of the daily challenge. The winner remains in the game while the loser is eliminated.
Starting at the 5th episode, it was announced that the remaining eliminations for the season would be double eliminations in which two players are eliminated. The losing male and female players, or captains, from the daily challenge form a team. The nominated player must then call-out a partner of the opposite gender to form their opponents for the elimination; the gender of the nominated player alternates each episode. The winning team remains in the game while the losing team is eliminated.
Twists
Lifesaver: Implemented for the first four episodes, the winning player or winning team captain of the non-designated gender for the elimination round is granted the Lifesaver. At the Arena, they must choose whether or not to use the Lifesaver to save the nominated player from competing in the elimination. In the event that the Lifesaver is used, the players eligible to vote (this time excluding the saved nominee) must publicly vote to select a replacement nominee for the Arena.