"While you are at Hogwarts, your triumphs will earn your House points, while any rule-breaking will lose House points. At the end of the year, the House with the most points is awarded the House Cup, a great honor. I hope each of you will be a credit to whichever House becomes yours."
-- Minerva McGonagall (PS7)
Points are given or taken away to reward or punish the behavior of students. Points are accumulated over the course of the school year, at the end of which a House Cup is awarded to the house with the most. Giant hourglasses set in niches along one wall in a corner of the entrance hall record the points for all to see; Gryffindor’s is filled with rubies, Ravenclaw’s with sapphires, Hufflepuff’s with diamonds, and Slytherin’s with emeralds. As a teacher or other authorized party speaks the words awarding or deducting points, the appropriate hourglass or hourglasses are automatically updated (PS15, OP28, OP38).
Points by year:
Commentary
Notes
Prefects are allowed to take points for infractions, but not from fellow Prefects (OP28).
NOTE: In the original version of OP, this was very confusing. It seemed from the text that Prefects were NOT allowed to take points, although Percy had clearly done so in book two. Rowling partially answered the question on her website, but it wasn't until the revision to the text (summer 2004) that the matter was resolved. Here are the original incorrect version and the updated, corrected version of the passage:
Old version:
'Afraid I'm going to have to dock a few points from Gryffindor and Hufflepuff,' he drawled.
'It's only teachers who can dock points from houses, Malfoy,' said Ernie at once.
'Yeah, we're prefects, too, remember?' snarled Ron.
'I know prefects can't dock points, Weasel King,' sneered Malfoy. Crabbe and Goyle sniggered. 'But members of the Inquisitorial Squad -'
New version:
'Afraid I'm going to have to dock a few points from Gryffindor and Hufflepuff,' he drawled.
'You can't take points from fellow prefects, Malfoy,' said Ernie at once.
'I know prefects can't dock points from each other,' sneered Malfoy. Crabbe and Goyle sniggered. 'But members of the Inquisitorial Squad -'
In the films, the house point hourglasses are on the wall behind the teachers' table in the Great Hall, while in canon they are located in the Entrance Hall.
Before J.K. Rowling's Twitter, it was previously unknown what is in the Hufflepuff hourglass. J.K. Rowling replied to a fan tweet, saying it is filled with diamonds.
From the Web
https://www.reddit.com/r/harrypotter/comments/2dovyb/has_anyone_ever_figured_out_how_many_house_points/
Pensieve (Comments)
Tags: houses points punishment rewards rivalry rule-breaking rules