Editing Survivor (franchise) (section)

===Castaways and tribes===
[[File:Survivor-camp.jpg|right|thumb|The tribe camp near the end of ''[[Survivor: Borneo]]''. Tribes must build themselves basic shelters from natural resources and through reward items earned during the competition.]]
Players for each season are selected through applicants and casting calls, down-selecting to between 16 and 20 players and additional alternates. American version host [[Jeff Probst]] noted that while 16 castaways assist in splitting the tribes with respect to age and sex, they have used 18 or 20 to provide them "wiggle room" in case of player injury or if one should want to quit the game.<ref>{{cite magazine | url = http://popwatch.ew.com/2009/10/23/jeff-probst-blogs-survivor-samoa-episode-6/ | title = Jeff Probst blogs 'Survivor: Samoa': episode #6 | first = Jeff | last = Probst |author-link1=Jeff Probst | magazine = [[Entertainment Weekly]] | date = October 23, 2009 | access-date = October 23, 2009}}</ref>  These players undergo physical and psychological evaluation to make sure they are physically and mentally fit for the survival endurance and will not likely quit during the filming period, replacing those that are questionable with the alternates. In one case, ''Fiji'', on the day before filming was to start after they had dismissed their alternates, one of the castaways opted out of the competition, forcing production to start with 19 players and adapting the activities of the first few days to accommodate the odd number of players.<ref>{{cite web|url=http://asapblogs.typepad.com/theslug/2007/01/jeff_probst_tal.html|title=Jeff Probst Talks "Survivor: Fiji"|access-date=January 12, 2007}}</ref>

Tribes may be predetermined by production before filming starts. Often this is done to equalize the sexes and age ranges within both tribes. Other seasons have had the tribes separated by age, gender, race or other characteristics. In other cases, the tribes may be created by the castaways through schoolyard picks. Most often, only two tribes are featured, but some seasons have begun with three or four tribes. Once assigned a tribe, each castaway is given a [[Neck gaiter|buff]] in their tribe color to aid the viewers in identifying tribal allocation. Tribes are then subsequently given names, often inspired by the local region and culture, and directions to their camps.

At their camps, tribes are expected to build a shelter against the elements from the local trees and other resources. Tribes are typically given minimal resources, such as a machete, water canteens, cooking pots, and staples of rice and grains, though this varies from season to season. Sometimes, tribes are provided with a water well near the camp, but require the water to be boiled to make it [[Drinking water|potable]], necessitating the need for the tribe to build a fire. The tribes are encouraged to forage off the land for food, including fruits, wild animals, and fish.

====Tribe swaps====
In some seasons, tribe swaps occur where one or more players shift from one tribe to another. These new tribal designations are often determined by random draw or schoolyard pick. When these occur, those players that shift tribes are given new buffs for their new tribe and return to that tribe's camp, with any personal possessions from their former camp moved with them. In seasons with more than two tribes, tribe swaps often reduce the number of tribes to two. In ''[[Survivor: Cambodia]]'', a tribe swap increased the number of tribes from two to three; a second tribe swap later in the season reduced the number of tribes back to two.

Tribes that have lost too many members may be absorbed by the other remaining tribes, as seen with the Ulong tribe in ''[[Survivor: Palau]]'' and the Matsing tribe of ''[[Survivor: Philippines]]''; in the former case, the lone remaining Ulong member joined the opposing Koror tribe and the tribes were treated as if they were merged, whereas in the later case the two remaining Matsing members were randomly assigned to the two remaining tribes. Alternatively, in ''[[Survivor: All-Stars]]'', the tribe that placed third in a designated challenge was disbanded, with the members reallocated to the other two tribes by schoolyard pick.

====Tribal merge====
At a point in or around the middle of the game, the remaining tribes are merged into one. All of the players then live in a single camp, and are given new buffs and instructed to select a new tribe name and paint a tribe flag. The merge is often signified with a feast. Though the merge often occurs when approximately 10 to 12 players remain, the tribes have been merged with as many as 13 players (as many of the seasons since ''[[Survivor: Cambodia]]'') and as few as eight (as in ''[[Survivor: Thailand]]'').