Hogwarts Express MUSH

Quidditch is the wizarding sport in the UK. Often described as being similar to football (soccer) on broomsticks, it is the sole extracurricular sport at Hogwarts and the professional Quidditch World Cup has a turnout of thousands every year.

Equipment
There are four balls in Quidditch.
  The red Quaffle, which is red and roughly the size of a football (soccerball). The Chasers pass this one back and forth.
  The two black Bludgers, which are made of iron and fly around trying to knock players off their brooms.
  The golden Snitch, a winged ball, roughly the size of a golf ball, that flies around of its own volition.
There are also three hoops which are raised high off the ground.

Teams
Quidditch is played with two teams of seven. All seven players are mounted on broomsticks. The breakdown of players is as follows:
  Chasers handle the Quaffle. By combining flying and passing, they need to get it to the opposite end of the pitch and throw it through one of the scoring hoops. Every goal scored is worth 10 points. (For the purpose of the MUSH, we have coded it so each goal earns each team 30 points to make the totals look right. Canonically these goals are only worth 10.) Each team has three Chasers.
  Keepers guard the hoops in order to keep the Chasers from scoring. They are the only players allowed within the crease. There is only one Keeper on each team.
  Beaters are armed with heavy wooden bats. Their task is to keep the Bludgers away from their teammates and hit them towards their opponents. There are two Beaters per team.
  Seekers try to catch the Snitch. The game doesn't end until the Snitch is caught and this action earns the team 150 bonus points, so frequently catching it wins the game.

Gameplay
The Bludgers and the Snitch are released, and then the referee tosses the Quaffle up into the air. The Chasers pass the Quaffle up the pitch and attempt to score by throwing the ball through the opposing team's hoops, scoring 10 points each time. The game does not end until one of the Seekers catches the snitch, earning their team an additional 150 points. Whichever team has the most points at the end wins.

There are literally hundreds of ways to commit a foul, many of which involve different ways of touching other players and their broomsticks in order to mess up their flying or magically charming the balls or broomsticks. Quidditch players are not permitted to cast spells during the game. In addition, the only players allowed within the Keeper's crease are the Keeper and the Chaser with the Quaffle. Typically, the referee will hand out penalty shots in reaction to fouls.