Hogwarts

Hogwarts, a fictional school in Scotland, is the setting for many Harry Potter fanfics. It is the only school of Witchcraft and Wizardry in Britain, and is considered by many to be the finest in the entire world. Muggles are unable to see Hogwarts because of the anti-Muggle magical wards; they will only see a ruined castle that they have no desire to approach. School is in session from September 1st to June 30th, with a two-week break at Christmas and a one-week break at Easter, during which students can go home if they wish (and their parents want them). Travel to and from Hogwarts is conducted by a train from Kings Cross Station in London, and the journey back seems to take less time than the initial journey there on September 1st.

Hogwarts Houses
Students are divided into four houses in their first year at Hogwarts, during the Sorting Ceremony that takes place upon their arrival. A common trait of a Sue, either of the OC or possession variety, is that they are placed into two or more houses, a new house is created especially for them, or a long forgotten house, normally attributed to Merlin, is reopened for their use. If a Possession Sue is involved, then Harry Potter is normally the affected party. Otherwise, the Sue generally ends up in the same house as her Lust Object.

The houses are named after the Four Founders, and the attributes required to enter a house are the ones that that particular Founder preferred. Students are Sorted in alphabetical order by means of the Sorting Hat, a raggedy, sentient, pointed hat with a tear at its brim like a mouth, which reads the student's mind to determine their personality traits. The Hat can be influenced by what the student wants if there are two possible houses that they could fit into, such as during Harry Potter's Sorting, when he could have gone into Gryffindor or Slytherin. Presumably the Hat can't be coerced into Sorting a student into a house that they do not belong in, though Sues manage it quite often.

During the school term students can be rewarded or punished for their behaviour by the addition or removal of house points. The house with the most points, which are represented by jewel-filled hourglasses in the Great Hall, wins the House Cup for that year.

Gryffindor
Gryffindor is the house that Harry Potter, Ron Weasley, and Hermione Granger belong to. Therefore it is where much of the action in Harry Potter, both in canon and in fanfiction, takes place. Gryffindor is associated with courage and bravery, which is often shown in fanfiction as near-suicidal recklessness.


 * Founder - Godric Gryffindor
 * Head of House - Minerva McGonagall
 * Colours - Scarlet and Gold
 * Mascot - Lion
 * Ghost - Sir Nicholas de Mimsy-Porpington, aka Nearly Headless Nick
 * Location - Seventh floor, behind the painting of the Fat Lady

Hufflepuff
Hufflepuff is the house that produced Cedric Diggory, Nymphadora Tonks, Susan Bones, Hannah Abbot, and Zacharias Smith, amongst others. The Hufflepuffs aren't shown as much as the Gryffindors and Slytherins, but they generally tend to side with Gryffindor during inter-house disputes. Occasionally, a Possessed!Harry will be Sorted into Hufflepuff. Hufflepuff House is associated with hard work and loyalty, which many fanfiction writers seem to equate as weak push-overs with no will of their own. Helga Hufflepuff's cup was one of Voldemort's Horcruxes.


 * Founder - Helga Hufflepuff
 * Head of House - Pomona Sprout
 * Colours - Yellow and Black
 * Mascot - Badger
 * Ghost - The Fat Friar
 * Location - Hidden by barrels, near the kitchens

Ravenclaw
Ravenclaws noted in the Harry Potter books are Luna Lovegood, Cho Chang, Penelope Clearwater, and Moaning Myrtle. Like the Hufflepuffs, Ravenclaws tend to side with Gryffindor during Gryffindor-Slytherin disputes. A Possessed!Harry will sometimes be Sorted into Ravenclaw. Ravenclaw is associated with intelligence, creativity, wit and wisdom, which fanfiction authors translate to know-it-all annoyingness. Rowena Ravenclaw's diadem was one of Voldemort's Horcruxes.


 * Founder - Rowena Ravenclaw
 * Head of House - Filius Flitwick
 * Colours - Blue and Bronze (books), Blue and Silver (films)
 * Mascot - Eagle (books), Raven (films)
 * Ghost - The Grey Lady (Helena Ravenclaw)
 * Location - Ravenclaw Tower, west side of Hogwarts

Slytherin
Slytherin is the main rival of Gryffindor in the Harry Potter series, and is the house that Lord Voldemort, Severus Snape, Draco Malfoy and Bellatrix Black come from. Possessed!Harry is commonly Sorted into this house, either to change it from the inside out or because he has turned into Dark!Harry. Whenever there is an argument between two of the other houses, Slytherin will always take the side that isn't Gryffindor, such as during the Triwizard Tournament. Slytherins are known for being cunning and ambitious, which often leads them to take a less than moral path in life. Salazar Slytherin was believed to have wanted all non-purebloods banned from the school, a view which many Slytherins perpetuate up to the time of the books. It is commonly stated in fanon that all Slytherins are pureblood, but even in canon there are several halfbloods in the house, most notably Severus Snape and Tom Marvolo Riddle. Slytherin's locket was used to house one of the Horcruxes made by Voldemort.


 * Founder - Salazar Slytherin
 * Head of House - Severus Snape (books 1-6), Horace Slughorn (book 7)
 * Colours - Green and Silver
 * Mascot - Snake
 * Ghost - The Bloody Baron
 * Location - Behind a bare stone wall in the dungeons

In Fanon
In fanon, there may be the addition of a fifth house, often for an extra special Mary Sue; this is a charge. Another common facet of fanon is the affiliation between Hogwarts houses and old magical elements. While being a suitable means by which to convey extra-specialness, it should be noted that any attempt to draw correlations of any description between Hogwarts houses and non-chemical elements will meet with skepticism by the general populace of HQ. Especially if druid princesses are involved. They've seen too many of those.

Notable Locations
There are many locations mentioned in the books that are important to the plot. This is a list and description of a few of them.


 * Great Hall
 * The Great Hall is where all meals and feasts are consumed, important announcements are made, the House and Quidditch Cups are awarded and the Sorting takes place. There are five tables in here, one for each house and one for the faculty. The Slytherin table is closest to the door, with the Ravenclaw table next, then the Hufflepuff table, and the Gryffindor table is the furthest away from the door. The High Table is at the front of the room, on a raised platform so the teachers can scan the student tables for any misdeeds. The ceiling of the Great Hall is enchanted to show the sky outside, presumably so students with outdoor lessons such as Care of Magical Creatures know how wet they are going to get. There are high windows all around the outside of the Hall that show the grounds outside, so students can sit and look outside as they eat. If a badfic states that the scene takes place in the Great Hall without specifying the occasion, the setting will default to a feast.


 * Forbidden Forest
 * The Forbidden Forest is a large, dangerous forest that lies at the edge of the Hogwarts grounds. Many creatures can be found within its borders, including unicorns, centaurs, Thestrals, and Acromantula. During Order of the Phoenix, a giant named Grawp was hidden within the forest by Hagrid. One of the more unusual things found in the forest is a charmed car that used to belong to Arthur Weasley, which began to show signs of sentience after Ron Weasley and Harry Potter rammed it into the Whomping Willow in Chamber of Secrets. Students are sometimes given detention assisting Hagrid in the Forbidden Forest, such as when Hagrid needed help hunting down a unicorn-killer in Philosopher's Stone. As the name implies, it is against school rules to enter the Forbidden Forest without permission.


 * Quidditch Pitch
 * The Quidditch pitch is where the students of Hogwarts play Quidditch, hence its name. It was also the location for the Third Task of the Triwizard Tournament in Goblet of Fire; a giant maze filled with traps and deadly creatures that, thankfully for the Quidditch players of Hogwarts, was removed after the Task was ended. It was here that Harry won almost all of the Quidditch games that he played for the Gryffindor team, despite the best underhanded efforts of the Slytherin team. The Quidditch pitch is oval in shape, with three hoops at either end for the Quaffle to be thrown through, and is surrounded by tall stands that are capable of seating the entire student body of Hogwarts. There is a magical barrier surrounding it that prevents the Snitch flying away and the Bludgers from attacking the assembled, defenceless students.
 * The Locker Rooms
 * Where the Quidditch teams go to change and listen to their captains' pre-game pep talks. In badfic, it's the usual place for Harry and another male character to go for some secretive snogging or creative sex.

Uncanonical Locations
There are some places mentioned in fanfic as being part of Hogwarts that inexplicably have never actually been mentioned in canon. These are usually places to arrange illicit trysts.


 * The Club
 * Often, fanwriters postulate the existence of a secret drinking/dancing venue either within Hogwarts or connected to it via a secret passageway.


 * The Music Room
 * A presumed rehearsal space for the Frog Choir and/or the Hogwarts Orchestra, which are canon to the movieverse, or an entirely made-up music club. The Frog Choir may also be canon to the bookverse per Word of God (Rowling "simply loved the idea"), but in any case, they practice in the Great Hall.

Hogwarts as a Character
Oddly enough, Hogwarts features as a sapient character in the following PPC missions:


 * 'Pure Evil' (NSFW/NSFB), Agents Eileen (DMSE&R) and Jake (DMS - Halo), March 2010
 * 'So Much for Subtlety', Agents Desdendelle and the Librarian (DF) with Agents Rina Dives and Zeb (DMS) and Corolla (DoSAT), May 2015

If we had a nickel for every time this happened, we'd have two nickels—which isn't a lot, but it's weird that it happened twice.