The positions in Quidditch, a competitive sport in the wizardry world of Harry Potter, are beaters, chasers, keepers and seekers. Quidditch is a fictional semi-contact sport in the Harry Potter novels and movies, played by both wizards and witches.
In J.K. Rowling's book, "Quidditch Through the Ages," she lists the official rules for Quidditch. In the game, four balls are released onto the field. Chasers must try and obtain a red ball called the quaffle and throw it through hoops for 10 points. The keeper of the team then releases the ball back into play. Meanwhile, the seeker tries to grab a tiny gold ball called the snitch. Grabbing it ends the game and gains the team that caught it 150 points. Throughout the entire game, there are two heavy balls called bludgers that slam into players on the field. The beaters must protect their team mates by hitting the bludgers with their bats.
There is a real life sport called Quidditch that was inspired by the Harry Potter novels and movies. The rules are very similar to the game in the novels and movies. However, they change certain things. For example, since they cannot enchant a snitch, they have a neutral player run around the field with a snitch attached to his wristband and it is worth 30 points instead of 150.