Each season 3 or 4 (it varies) of the group are chosen on the first night to be "the traitors." The rest of the group are "the faithful." Every night the traitors murder one of the faithful to eliminate them from the game. Also every night there is a round table where the group collectively votes out a player that they believe to be a traitor (but could well be a faithful). So you lose two players every episode, it moves fast. In the meantime they work together to complete missions where they can add money to the prize pot. At the end of the game if they have voted out all of the traitors, the remaining faithful split the money. If one or more traitors make it to the end, they get the money. When a traitor is voted out the remaining traitors have the opportunity to recruit a faithful to join them, but they don't always, so the remaining players are never really sure how many traitors remain in the game, or if someone has changed from a faithful to a traitor.