Immunity Challenge

The Immunity Challenge is the most important aspect of the game. Winning this challenge will secure a tribe or an individual safety for the following tribal council.

Tribal Immunity
During the tribal phase of the game, the tribes vie for the ownership of the Immunity Idol. The winning tribe will be granted safety from the upcoming Tribal Council.

In rare cases, there are double eliminations and both tribes go to Tribal Council, where the Immunity Idol temporarily retires and is replaced with the Immunity Necklace which is usually only available post-merge. But after the double boot twist, the idol returns until the merger.

Giving Tribal Immunity Away
To date, there have been two instances when a tribe has given up their Tribal Immunity.
 * Jeff Probst in Survivor: Fiji announced that if Moto (the winning tribe) wanted to keep their luxurious campsite they must sacrifice Immunity to Ravu which they did.
 * In Survivor: One World, the Manono tribe turned up to Tribal Council after winning Immunity to vote out Bill Posley thus granting Salani exemption.

Individual Immunity
After the merge, where there is only one existing tribe, the remaining contestants compete in individual challenges to seek possession of the Immunity Necklace, which guarantees safety at Tribal Council for its bearer. Unlike the tribal Immunity Idol, which gives exemption to its host, the incumbent wearer of the necklaces still must attend Tribal Council and cast a vote, but that player cannot be voted out. Since, individual immunity is transferable, giving safety to its new wearer, while leaving the original winner vulnerable.

On some occasions, Individual Immunity has been played for during the pre-merge stages of the game (Usually this occurs during Double Tribal Councils). It can work one of four ways:
 * An Individual Immunity necklace appears at a certain location on the island. The first members of each tribe to get to them are granted Immunity at the first Tribal Councils they attend. (Survivor: Micronesia, Survivor: Gabon)
 * Both tribes compete simultaneously for a shot at wining an Individual Immunity on their tribe (Survivor: Heroes vs. Villains, Survivor: Nicaragua).
 * One tribe wins a reward, and the members of that winning tribe then compete for Individual Immunity. (Survivor: Vanuatu, Survivor: Guatemala, Survivor: Gabon)
 * One tribe wins a reward during a Double Tribal Council. As part of their reward, they are able to give Individual Immunity to a member of the tribe who goes second. (Survivor: Palau, Survivor: Cook Islands)

No Immunity
There has been one case that no one post-merge has come to Tribal with immunity. During, the Jury won an immunity challenge that would send Darrah home.