the first u.s. season of "survivor" followed the same general format as the swedish series. sixteen or more players, split between two or more "tribes", are taken to a remote isolated location (usually in a tropical climate) and are forced to live off the land with meager supplies for 39 days (42 in ""). frequent physical and mental challenges are used to pit the teams against each other for rewards, such as food or luxuries, or for "immunity", forcing the other tribe to attend "tribal council", where they must vote off one of their tribemates.