Recap / The Challenge

Seasons:

1. Road Rules: All Stars: While part of the series, it has no Road Rules cast members participating and is more akin to a normal season of Road Rules, just with ex-Real World cast members taking part.
2. Real World/Road Rules Challenge: The first real season, taking six Real World cast members and six Road Rules cast members and getting them to face off against each other.
3. Challenge 2000: Take the previous season and change the cast members for different ones and repeat.
4. Extreme Challenge: Another season of six vs. six, Real World vs. Road Rules battles. Notable for having one invokedMissing Episode which featured dressing up as famous couples in a fetish shop.
5. Battle of the Seasons: The first season of the show to place in elimination of teams. During this show, sixteen pairs of two (one male, one female) competed against each other to see if Road Rules or Real World were better. Notable for Emily (Road Rules) actively eliminating threats, much to the anger of everyone else. Also notable for Mike "The Miz" getting drunk and starting up his whole wrestling persona.
6. Battle of the Sexes: Take the format of the previous season and instead make the two teams "men vs. women". Notable for Puck almost getting kicked off the show for a spit-fight, Puck getting married, Puck trashing the hotel and quitting because of his wife getting deported... hell, just anything involving Puck.
7. The Gauntlet: The first show to remove the points value of the previous seasons and the first to add elimination challenges. After each mission, both Real World and Road Rules had to vote somebody into elimination. The loser went home empty handed while the winner stuck around, often to their own team's annoyance.
8. The Inferno: Once again, two teams of Real World and Road Rules cast members face off. Notable for a distinct elimination practice where, after having voted a member of the opposing team into the Inferno, they could potentially have the chance to win a "Life Saver", protect themselves from elimination, and then select their Inferno replacement.
9. Battle of the Sexes 2: Back to the "men vs. women" format, this time ditching the points system and changing to a captain system. Before each challenge, each team would nominate three captains. Win, and those captains decide who is going home from their team. Lose, and everyone else votes one of the captains off the show.
10. The Inferno II: Because Road Rules wasn't around anymore, the team themes had to be changed from here on out. This challenge saw contestants placed into 'Bad Asses vs Good Guys'.
11. The Gauntlet 2: Originally meant to be "new school vs. old school" contestants, this season was shifted around a little when not enough "old school" contestants wanted to appear. Instead, it was Veterans (contestants who had been in two or more seasons already) vs Rookies (first-time or one-shot contestants). In a change from usual team challenges where the eliminations could remove somebody from either team, here if you lost a main challenge, you and only your team would lose a member. Several other twists also appeared.
12. Fresh Meat: Featured alumni competing in male-female pairs with new castmates who did not previously feature appear in The Real World or Road Rules. The winning pair of each mission chose one pair to go into elimination, while the remaining players voted for the other pair to go into the "Exile" elimination round.
13. The Duel: Promoted as an "every man for himself" challenge, everyone competes individually, and there are only two winners (one of each gender).
14. The Inferno 3: Similar to Inferno II, this challenge also had teams of "Bad Asses" vs "Good Guys".
15. The Gauntlet III: Similar to Gauntlet 2, this challenge also had teams of Veterans vs Rookies.
16. The Island: Unlike previous challenges, this one featured no missions, and each episode had three people go into an elimination round in hopes to earn a 'key' to the final challenge. The remaining players would have to chose between the two non-winning contestants, in a Survivor-style vote-off. Also like Survivor, they were on an island with limited supplies, unlike in previous challenges where they lived in a large house.
17. The Duel II: Similar to the previous Duel, it featured the same format.
18. The Ruins: Had two teams of "Challengers" (people who had never won a challenge before) vs. "Champions" (people who have won before). Prior to each mission, each team nominates a group of three players of each gender within the team for elimination; after that challenge, the winning team's nominated group picks the match-ups for the "Ruins", which consist of a male Challenger against a male Champion, and a female Challenger against a female Champion.
19. Fresh Meat II: Similar to the previous Fresh Meat, featured the same format.
20. Cutthroat: This challenge featured three teams, and each week they would compete in missions. The winning team of the mission was immune from elimination, while the other two teams had to vote in what players to go into the "Gulag" elimination round.
21. Rivals: Featured 'rivalries' of previous castmates in same-sex pairs, and they had to compete together throughout the challenge. Each challenge alternates between being a female elimination or a male elimination. In the end, there would be two winning pairs, one of each gender.
22. Battle of the Exes This challenge featured thirteen teams of ex-couples competing in a challenge where the winner is safe from elimination and will be known as "The Power Couple", and they are responsible for choosing one team to go into the elimination round called "The Dome", along with the team that came in last-place in the challenge. In the end, there would be one winning pair.
23. Battle of the Seasons: Each team consists of two men and two women from select seasons. After each challenge, there is a winning team and a losing team. The losing team is automatically sent to "The Arena" and faces possible elimination. The winning team become the Power Team, and selects one team to battle against the last-place team in the Arena. The teams entering the Arena must select one player of each gender from their own team to compete in the elimination. If the teams entering the Arena cannot decide which players will compete in the elimination, the Power Team chooses for them. The winning pair in the elimination rounds return to their season and stay in the game, while the losing pair is eliminated, reducing their season to two players.
24. Rivals II: This challenge featured the same format as the previous Rivals season.
25. Free Agents: Each challenge is either individual, pairs, or teams. The winning individual/team/pair selects someone to go into elimination, while the rest of the players participate in "the Draw" where whoever draws the "kill card" goes into the elimination round.
26. Battle of the Exes II: This challenge featured the same format as the previous Battle of the Exes. Notable for being the last challenge with Diem, who had to leave while filming for becoming ill again with cancer, before her inevitable death months later.
27. Battle of the Bloodlines: This challenge consisted of pairs of two, featuring an alum of The Real World, The Challenge, or Are You the One? with a relative. The winning pair of the mission selects another pair to go into elimination (the Pit) against the losing pair, with gender-based eliminations.
28. Rivals III: Similar to the previous Rivals installments, except this one featured opposite-sex rivals.
29. Invasion of the Champions: Eighteen "Underdog" players (contestants who never won before) compete for a spot in "The Oasis", and eventually, eight former Champions join the game to compete against them. The Champions compete in eliminations against each other, and the Underdogs compete in elimination against each other.
30. XXX: Dirty 30: Similar to Free Agents, where challenges may be individual, pairs, or teams. The contestants also have a shot at "redemption" to return to the game. In honor of being the 30th season, the prize money was increased to $1,000,000, unbeknownst to the contestants.
31. Vendettas: Each of the contestants has an unresolved grudge with other contestants. Notably, this was the first season to feature alumni from Big Brother US, as well as the British shows Ex on the Beach and Geordie Shore. It was also the first season to have only one winner.
32. Final Reckoning: A similar rivalry-based setup as Vendettas, though this time, the rivals are competing together in pairs. Introduced alumni from Bad Girls Club and Vanderpump Rules, as well as the American version of ''Ex on the Beach.
33. War of the Worlds: Contestants were put into male/female pairs until only seven teams remained, at which point the pairs were broken up and everybody competed as individuals. Sixteen Challenge veterans and eighteen new contestants competed. Introduced alumni from The Bachelor Canada, The Bachelorette, Celebrity Big Brother UK, Love Island UK, Survivor Turkey, American Ninja Warrior, Party Down South, the Brazilian version of Ex on the Beach, and Floribama Shore.
34. War of the Worlds 2: Players are divided into two teams, Team USA and Team UK. Introduced contestants from Shipwrecked, Survival of the Fittest, and BKCHAT LDN.
35. Total Madness: Challenges may be individual, pairs, or teams. Winning an elimination round earns a player a Red Skull, a requirement to compete in the Final Challenge.
36. Double Agents: Contestants compete in male/female pairs that regularly shift as they are eliminated. At each challenge, the winning pair become the Double Agents, who select one of the two competitors in the elimination round. Introduced alumni from America's Got Talent, WWE NXT, and Ultimate Beastmaster.
37. Spies, Lies & Allies: Introduced alumni from Warsaw Shore, Paradise Hotel, Too Hot to Handle, 12 Dates of Christmas, the Nigerian version of Big Brother, and the Romanian, Spanish, and Turkish versions of Survivor.

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