Kidnapping

Kidnapping (although in later seasons Observing) is a twist that has been used in multiple seasons of Survivor. The winning tribe of a Reward Challenge will choose a member of the losing tribe to join them for a while at their camp.

The twist was used primarily in Survivor: Pearl Islands, Survivor: All-Stars and Survivor: China and rehashed in Survivor: Samoa under a new format whereupon the winning tribe will select one of their own to observe the opposing tribe back at their camp.

On two occasions in Survivor: Pearl Islands and Survivor: All-Stars, the kidnapped castaways did not go back to their tribe to attend Tribal Council.

Pearl Islands
Rupert Boneham was kidnapped by the Morgan Tribe (Pick A Castaway...Any Castaway) after the Immunity Challenge. Because of this he was exempt from Drake's Tribal Council and even participated in a Reward Challenge as part of the Morgan Tribe. A few days into his kidnapping, Rupert was offered the chance to permanently switch tribes, which he refused.

All-Stars
Kathy Vavrick-O'Brien was kidnapped by the Chapera Tribe (Sorry...I Blew It). After the Immunity Challenge, she enjoyed a similar situation to that of Rupert Boneham from the previous season but was not offered the chance to switch tribes.

China
The winning Tribe of the Reward Challenge would select one member from the losing tribe to join them back at camp. The chosen Survivor would be given a scroll which they must give to a member of the winning Tribe to open in private, which would contain a clue to the location of the winning Tribe's Hidden Immunity Idol.

Samoa
The winning Tribe of the Reward Challenge would have their Leader choose one member to go to the other tribe as opposed to taking part in the reward. Known as "Observing," they would then be given the opportunity to observe their camp life and relay any information back upon their return.

Kidnapped

 * Rupert Boneham - Survivor: Pearl Islands
 * Kathy Vavrick-O'Brien - Survivor: All-Stars
 * Nate Gonzalez - Survivor: Cook Islands
 * Jaime Dugan - Survivor: China
 * Leslie Nease - Survivor: China
 * Dave Cruser - Survivor: China
 * James Clement - Survivor: China

Observed

 * Yasmin Giles - Survivor: Samoa
 * Shambo Waters - Survivor: Samoa
 * Laura Morett - Survivor: Samoa

Trivia

 * Rupert Boneham was the first person to be kidnapped in the history of Survivor.