Sixteen or more castaways are split between two or more "Tribes", are taken to a remote isolated location and are forced to live off the land with meager supplies for roughly 39 days. Frequent physical challenges are used to pit the tribes 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 players. Once about half the players are remaining, the tribes are merged into a single tribe, and competitions are on an individual basis; winning Immunity prevents that player from being voted out, while several that are voted out at this stage form the game's "Jury". Once down to two or three people, a Final Tribal Council is held where the remaining players plead their case to the jury members. The jury then votes for which player should be considered the "Sole Survivor" and win the $1 million prize. Survivor has introduced numerous modifications, or "twists", on the core rules in order to keep the players on their toes and to prevent players from relying on strategies that succeeded in prior seasons. These changes have included tribal switches, seasons starting with more than two tribes, the ability to exile a player from a tribe for a short time, Hidden Immunity Idols that players can use to save themselves at Tribal Council and a chance to return to regular gameplay after elimination through "Redemption Island".
The 16 players, divided into two tribes (Samburu and Boran), arrive at the Shaba National Reserve in Kenya and set up camp. For Immunity, the tribes must each drag a heavy cart over rough terrain while lighting a series of torches. The first player is voted out of the game.
The tribes play for blankets, water containers and food in the “Stairway to the Stars” Reward Challenge. Teams must carry five logs through a series of obstacles to a tower and build a staircase. For Immunity, each player must drink a shot glass of cow's blood mixed with milk. If a player fails, his or her tribe loses. At Tribal Council, a second player is voted out.
The tribes try to win 100 gallons of fresh water by rolling a giant boulder through an obstacle course. For Immunity, the teams must create a distress signal that can be clearly seen from the air. The third player is voted out of the game at Tribal Council.
The tribes compete for cooking supplies in the “Caught in the Web” Reward Challenge. Players must climb a web of rope and retrieve 12 baskets hanging from the web to win. For Immunity, the teams must pick up and move a camp with a hut 200 yards and then re-create the camp exactly as it was before. The fourth player is voted out of the game.
Three tribe members from each team are surprised to learn that they are switching sides and joining their rival tribes. After the switch, the teams compete for Reward by leading 20 goats from a starting pen to a destination pen 100 yards away. For Immunity, teams gather 20 puzzle pieces and put them together to complete the puzzle. The fifth person is voted out of the game at Tribal Council.
The teams play for a full food buffet by answering a series of questions about Africa. For Immunity, the players use bows and arrows to hit five targets. The sixth person is voted out of the game at Tribal Council.
The two teams merge and form the Moto Maji tribe. For Immunity, the players have one of their wrists attached to a rope that is connected to a bucket of water located directly above their heads. If they drop their arm, the water pours down on them. The last player standing wins. At Tribal Council, the seventh person is voted out of the game.
Jeff Probst hosts a look back at the first 21 days of the game in Kenya.
The players try to win two goats that can be traded in an African village for goods by catapulting nine items into a basket located on top of a tower. “Box Your Mind” is the Immunity Challenge, in which players must memorize items located inside a barrel. At Tribal Council, the eighth person is voted out of the game.
The players try to win a night at the movies to see “Out of Africa” by successfully completing an obstacle course. For Immunity, players attempt to start a fire using a magnifying glass. The ninth person is voted out of the game at Tribal Council.
The players are each given money to spend at a food auction. For Immunity, the players must answer correctly five questions about African folklore. The 10th person is voted out of the game at Tribal Council.
The players watch videos of their families, then try to guess the answers their family members gave to personal questions. The winner receives a Reward that includes an African safari. For Immunity, the players throw sticks to break pots with opposing players' names on them. The last person with an unbroken pot wins Immunity. The 11th person is voted out of the game at Tribal Council.
The castaways play “Swahili Scramble” for Reward. They each must find nine Swahili words hidden in letters on a board and then use them to solve a clue. The Reward includes the chance to deliver medical supplies to an AIDS hospital. The “Second Chance” Immunity Challenge combines elements from previous challenges, including an obstacle course and using bows and arrows. The 12th person is voted out of the game at Tribal Council.
The Final Four players answer questions about the 12 ousted castaways in the first of two Immunity Challenges. The second Immunity Challenge is an endurance battle in which the three remaining players place a hand on a wooden idol and their feet on stumps. The last person standing wins Immunity. Later, the seven jury members question the Final Two players and vote for the winner.