The Chapera Alliance is the dominant alliance of Survivor: All-Stars.
The original alliance was formed between Rob and Amber on Day 2, with Tom joining after Chapera lost their first Immunity Challenge on Day 12. The alliance (plus non-alliance members Alicia Calaway and Susan Hawk) unanimously voted out Rob Cesternino that night. When Saboga was dissolved the next day, Chapera chose Jenna Lewis and Rupert Boneham to become part of the tribe; both joined the alliance on Day 17, the same day that Susan quit the game.
Boston Rob's Deal
A tribe switch occurred on Day 23, splitting up the alliance temporarily. Amber remained on the new Chapera, while the other four members of the alliance were switched to Mogo Mogo. When the new Chapera lost the next day's Immunity Challenge, Amber was in danger of being voted out. Alicia was also added into the alliance during this time.
Rob made a deal with Mogo Mogo Alliance leader Lex van den Berghe, saying he would spare Lex after the merge if the new Chapera tribe spared Amber that night. As a result, Lex's alliance voted out Jerri Manthey.
The merge occurred on Day 27. Rob went back on the deal he made with Lex, voting with the rest of the alliance to oust him. The alliance stuck together the next day and voted out Kathy Vavrick-O'Brien, leaving them at a 6-1 advantage with the only remaining Mogo Mogo member being Shii Ann Huang.
Turning on Each Other
On Day 30, Shii Ann won immunity, forcing the alliance to turn on themselves. Alicia was voted out unanimously. Three days later, Shii Ann lost the Immunity Challenge and was voted out herself. On Day 36, Tom saw himself as the swing vote between the Rob/Amber and Rupert/Jenna pairs, but was blindsided when Rob decided it was too risky having Tom as a swing vote.
On Day 37, Amber won immunity, leaving the other three vulnerable. Rupert believed that Jenna would vote for Rob and force a tie, but Jenna turned on him and Rupert became the sixth member of the jury. On Day 38, Rob won the Final Immunity Challenge and voted out Jenna, leaving himself and Amber as the Final Two. Amber won the jury vote by a 4-3 decision and became the Sole Survivor.