Each season begins with a pool of contestants standing in separate square spaces of a large grid on the studio floor. Each contestant has a category in which they feel particularly knowledgeable. However, the producers of the show ultimately decide the categories the contestants have. Season 1 featured 81 contestants in a 9-by-9 grid; as of Season 2, 100 contestants play on a 10-by-10 grid. The floor measures 20 by 12 meters, or roughly 66 by 39 feet. The game progresses over the course of a season with the grand prize awarded to the contestant who ultimately controls the entire floor. Secondary prizes are awarded throughout the season to the contestant with the most territory at the end of each episode after a certain number of duels (usually eight, but on occasion nine). For season 2 and 3, every third episode (disregarding the finale's tiebreaker) has nine duels per episode. For the fourth season, every third and fourth episode (excluding the final two episodes) has nine duels per episode. One contestant is chosen at random (via "The Randomizer") to be a challenger and shown the categories of all opponents whose territories share at least one side with their own, then chooses one of them to challenge face-to-face in a head-to-head duel. The specifics of the duel remain undisclosed until the challenger selects an opponent, with the format defaulting to visual unless specified otherwise by the host. The two contestants take turns identifying a series of images or words associated with the challenged opponent's category. They are each given separate 45-second clocks, only one of which runs at any given time, starting with the challenger. The contestant in control must give a correct answer to stop their clock and
turn control over to their opponent. Infinite guesses are allowed without penalty, and a contestant may pass whenever desired; however, they must wait three seconds for a new image or text to be shown. Some categories are text-based, requiring contestants to perform tasks such as filling in the missing word(s) of a book title or song lyric, or naming the movie from which a famous quote is taken. Beginning in season 2, audio duels are introduced, requiring contestants to decipher answers via audio cue and providing visuals to indicate turn order. Season 3 introduced association duels, in which the contestant is shown three clues and must state their common link. Season 4 introduced video duels, which show clips instead of images. Season 5 featured duels in which the contestants had to decipher the clue while zoomed. Once a category has been selected and played, it is permanently removed from play and cannot be chosen again, ensuring each category can only be played once. The first contestant to run out of time is eliminated from the game (if the category is completed with all images or clues identified within time, the contestant with more time left wins the duel) and gives up all of their territory to the winner, who inherits the challenger's category or keeps their own (if the challenger). The winner may then either challenge another opponent or return to the grid; in the latter case, a new contestant is selected as a challenger at random from those who have not yet played a duel. This rule is a change from the original Dutch format, and instituted to prevent contestants from reaching the final duel without having already faced an opponent. Once all the remaining contestants have played a duel at least once, everyone becomes eligible for selection as a challenger. When only two contestants remain, the one controlling more territory (in season 1) decides which category is played. The other category remains unplayed. Beginning with season 2, the final duel is played as a best-of-three, with the first contestant to win two rounds declared the champion. Each remaining category is used for one of the first two rounds only. The contestant in control only selects which of the two known remaining categories will be played first (they will be the challenger in the first round, while the winner of the first round is the challenger in the second). If a third round is necessary, it will be played with a mystery category. The contestant who goes first will be decided randomly in the tiebreaker round. At the end of each episode, apart from the final episode, the contestant holding the most territory wins $20,000 (increased to $40,000 in season 4 for the first episode only). ==Results by contestant==