As you all know, every house has its own house team, as well as a reserve team in case somebody cannot make it to a match. How is it played? Here are the official rules:
Quote:
(Keredwel)
QUIDDITCH RULES: How To Play
Chasers and Keepers
The Chasers and the Keeper are basically the most vital players. They are the ones who need to be the most active. To start off, a Quaffle Question will be presented to the Chasers and the Keeper. This question is not for all Chasers though - the questions are asked in turn, so first the Gryffindors are asked the questions, for example, and after that the Slytherins and so on. The object of the game is to be fast.
Example question
Quaffle: How many fouls can be made in Quidditch?
As soon as the question is presented, the Chasers have to answer. If they answer correctly, they gain 10 points. But if the opposing Keeper manages to answer the question first, then the goal is blocked and no points will be handed out. If the Chaser who answers first answers wrong, no points will be given out. If the Keeper answers wrong, he/she has not been able to block the goal and 10 points will be given to the opposing team. Then another question is asked, this time targeted to the other team, and the game follows the same pattern.
Beaters
The Beaters don't have too important of a role, so they needn't be here all the time. Every once in a while a Bludger Question will be asked.
Example question
Bludger: Who holds the record for the fastest capture of the Snitch to date?
All the Beaters can answer this. The Beater who answers (correctly) first has thus hit the Bludger and deducted 10 points from the opposing team.
Seekers
The Seekers must be knowledgeable about HP and Quidditch in general, though they don't need to be so active all the time. At some points of the game, a Snitch Question will be presented. This will be a difficult question.
Example question
Snitch: Who was the first ever person to cross the Atlantic by broom?
The first Seeker to answer it will get a bit closer to catching the Snitch. After "catching" the Snitch three times, they finally really catch the Snitch and the game is over, giving the Snitch catcher's team an additional 150 points.
--+--
House points
The points are given to the houses judging by how many points they won the other team by. If, for example, Gryffindor won Slytherin 150-50, Gryffindor would get 100 points and Slytherin none.
--+--
In General
And so always the first person's answer is crucial. If they answer correctly, then it's good. If they answer wrong but someone answers correct after them, then it doesn't count. Everything relies on the first person.
For additional good luck, the Quidditch team is supported by the fans in the stands and the Cheerleaders.
Quidditch Announcements 
