Quidditch is a fictional sport invented by author J. K. Rowling for her fantasy book series Harry Potter. It is a dangerous but popular sport played by witches and wizards riding flying broomsticks. Matches are played on a large oval pitch with three ring-shaped goals of different heights on each side, between two opposing teams of seven players each: three Chasers, two Beaters, the Keeper, and the Seeker. There are three different balls: the Quaffle, the two Bludgers, and the Golden Snitch. The Chasers and the Keeper respectively score with and defend the goals against the Quaffle; the two Beaters bat the Bludgers away from their teammates and towards their opponents; and the Seeker locates and catches the Golden Snitch, whose capture simultaneously wins the Seeker's team 150 points and ends the game. The team with the most points at the end wins. Harry Potter plays as Seeker for his house team at Hogwarts. Regional and international Quidditch competitions are mentioned throughout the series. Aspects of the sport's history are revealed in Quidditch Through the Ages, published by Rowling in 2001 to benefit Comic Relief. A real-life version of the game has been created, in which the players use brooms, but run instead of flying.