In award-winning reality show SURVIVOR, a group of strangers (usually 16, sometimes more) ranging in age from 20ish to 60ish is "cast away" for 39 days in a remote tropical location and divided into tribes. The tribes compete against each other in challenges for rewards or immunity from elimination (once the number of players dwindles significantly, they start competing individually instead of at the tribal level). The last contestant standing wins $1 million and the title of Sole Survivor. Even as they form a society and work together to build shelters and win the challenges, the Survivors vote each other out of the game one by one at tribal council -- a formula thats been copied by countless reality/game shows since, from Big Brother to The Bachelor to American Idol. But the game changes in unexpected ways each season, too, deliberately churning up surprises: Past gimmicks have included bringing back players who were voted out, switching up the tribes after a few days, exiling players to a special island, dividing tribes along controversial lines (race, age groups, etc.), and so on.