Balls
There are three kinds in all. Four are used in the game.

Quaffle: Large and red, about the size of a Soccer ball, used to score goals. (Worth Ten Points)

Bludger: Two in a game, black. Slightly smaller than a Quaffle, fly around trying to knock players off brooms.

Snitch: Most important Ball in the game. Tiny, the size of a golf ball with wings, very fast and hard to catch.


Players
Seven play at one time for each team.

Chaser: Throw the Quaffle to each other trying to score goals. Three on each team.

Keeper: Kind of like a Soccer goalie. Guards the goal posts. One player at a time.

Beater: Uses a baseball-like bat to knock the bludgers at the other team. Two players.

Seeker: Flys around trying to catch the Golden Snitch, scoring 150 points if caught. One player at a time.


Other Rules
- No Time limit.

- Each goal scored by Chasers is 10 points.

- Penalty shots are given when you get fouled.

- Catching the Snitch is 150 points.

- The game is over when the Snitch is caught.
Found on MuggleNet.com