Format
A group of contestants (16 in the first series, 12 in the second) were marooned on a desert island and split into two tribes. For the first 20 days, the two tribes competed against each other in reward and immunity challenges. The tribe that won the reward challenge received a special treat that made their life on the island more comfortable. The tribe that won the immunity challenge was safe from any eliminations from the competition for three days.
Meanwhile, the tribe that lost the immunity challenge were forced to vote one of their own off the island. Contestants were free to discuss and scheme about who they wished to vote off, and many alliances were made and broken as the series progressed.
After 20 days, the remaining members of the two tribes merged into a single unit. Reward and immunity challenges were competed for on an individual basis, with the remaining contestants battling to prevent themselves from being voted off. After tribal merger, every contestant who was voted off joined a jury that would ultimately decide which of the two finalists won the £1,000,000 prize.
Read more about this topic: Survivor (UK TV series)