Hogwarts is divided into four houses, each bearing the last name of its founder. Throughout the school year, the houses compete for the House Cup and for the Quidditch Cup. Houses at Hogwarts are living and learning communities for their students. Each house is under the authority of one of the Hogwarts staff members. Each year, year level groups of every separate house share the same dormitory and classes. The dormitory and common room of a House are, barring rare exceptions, inaccessible to students belonging to other Houses.
Gryffindor
Gryffindor values courage, bravery, nerve, and chivalry. Gryffindor's mascot is the lion. Gryffindor's colours are scarlet and gold. The Head of this house is the Transfiguration teacher and Deputy Headmistress Minerva McGonagall. The house ghost is Sir Nicholas de Mimsy-Porpington, more commonly known as Nearly Headless Nick.
The Gryffindor dormitories and common room is in one of the castle's highest towers, and its entrance is on the seventh floor in the east wing of the castle and is guarded by a painting of The Fat Lady, who is garbed in a pink dress. She permits entry only after being given the correct password. Behind her painting is a large common room, with a fireplace, and two staircases leading up to the girls' and boys' dormitories.
There is a spell on the girls' staircase that prevents boys from using it; however, there is no such enchantment on the staircase to the boys' dormitory, allowing girls to use it whenever they wish, due to the founders' belief that girls were more trustworthy. The common room is very comfortable, and members of the Gryffindor house meet there for study groups, celebrations, or relaxation. The walls are lined with portraits, each one depicting a previous or current Head of Gryffindor.
The founder of the house is Godric Gryffindor. Gryffindor hailed from a moor which is now known as Godric's Hollow, a small West Country village in England. Godric Gryffindor was said to be the greatest duellist of his time. He also possessed skill at Muggle duelling, using his sword in combat. He, with the help of the other founders, transfigured the Sorting Hat into a sentient artefact to sort students after his lifetime.
Hufflepuff
Hufflepuff values hard work, patience, justice, and loyalty. The house mascot is the badger. Hufflepuff's calours are yellow and black. The Head of this house is the Herbology teacher Pomona Sprout. The house ghost is The Fat Friar.
The entrance to the Hufflepuff dormitories and common room entrance is concealed in a pile of large barrels in an alcove in the corridor that holds the kitchen. To enter, one must tap the barrel two from the bottom in the middle of the second row in the rhythm of "Helga Hufflepuff". Unlike any other house, the Hufflepuff common room has a repelling device that douses the illegal entrant in vinegar if the wrong lid is tapped or the rhythm is wrong. The Hufflepuff common room is filled with yellow hangings and fat armchairs and it has little underground tunnels leading to the dormitories, all of which have perfectly round doors, like barrel tops.
The founder of this house is Helga Hufflepuff. She was born in the 10th Century and came from the broad valleys of Wales. She was very tolerant. While the other founders chose to have special students, Hufflepuff accepted them all. Helga Hufflepuff had a gift for Food-related charms, and her recipes are still used as the basis for many Hogwarts feasts. Helga Hufflepuff also arranged for the house-elf contingent to work in the kitchens, giving them somewhere safe to work, where they would not be mistreated or abused.
Ravenclaw
Ravenclaw values intelligence, creativity, learning, and wit. The house mascot is an eagle. The house colours are blue and bronze. The Head of this house is the Charms professor, Filius Flitwick. The house ghost is The Grey Lady.
The dormitories are in Ravenclaw Tower, on the west side of Hogwarts. The common room, which went undescribed in the series until the climax of Deathly Hallows, is round and filled with blue hangings and armchairs, has a domed ceiling painted with stars and features a replica statue of Rowena wearing her diadem. Harry also notes that Ravenclaws "have a spectacular view of the surrounding mountains". A logical riddle must be solved to gain entry, whereas the Gryffindor and Slytherin common rooms only require a password (Hufflepuffs need to tap a barrel in the rhythm of "Helga Hufflepuff"), indicating that it may be easier for those students from other houses who possess a high degree of intelligence to enter this common room than others. Professor McGonagall, the head of the Gryffindor House, solves the riddle accurately.
The founder of this house is Rowena Ravenclaw. Noted for her intelligence and creativity and regarded as one of the greatest witches of the age. It is a popular historical theory that the location and name of Hogwarts were both chosen by Ravenclaw, who dreamt that a warty hog was leading her to a cliff by the lake. Ravenclaw came up with the ever-changing floor plan. Ravenclaw died sometime in the eleventh century, after she fell fatally ill. Legend had it that a broken heart is the cause — because her daughter Helena ran away with her diadem.
Slytherin
Slytherin values ambition, cunning, leadership, and resourcefulness. Slytherins have highly developed senses of self-preservation. Slytherins tend to take charge and possess strong leadership skills. Slytherins are often self-assured and confident of their own competence and can be very loyal. Another characteristic some Slytherins share is a tendency towards deep, unrequited love.
The house mascot of Slytherin is the serpent. The house colours are green and silver. The Head of House is Severus Snape. The ghost of Slytherin house is The Bloody Baron.
The Slytherin dormitories and common room are reached through a bare stone wall in the dungeons. The Slytherin common room is a long, low, dungeon-style room, under the Hogwarts Lake, furnished with green lamps and carved armchairs. The room is described have a greenish glow. Slytherin corresponds roughly with the element of water due to serpents being commonly associated with the sea and lochs in western European mythology, as well as serpents being physically fluid and flexible animals.
The founder of this house is Salazar Slytherin. He was a pure-blood wizard, noted for his cunning and determination. Slytherin built the Chamber of Secrets and left there his Basilisk behind. Salazar Slytherin was one of the earliest recorded Parselmouths and used this ability to control a Basilisk. He also was a Parselmouth - person who can speak language of serpents. Slytherin owned a wand made of Snakewood with a Basilisk horn core. It was passed down through the generation until it was stolen from Gormlaith Gaunt by her niece Isolt Sayre and later buried on the grounds of Ilvermorny School in North America.
