In the fictional Harry Potter universe, magic is what separates Muggles from witches and wizards. With magical ability witches and wizards can use wands to perform magic. People with magical ability also have the power to see things Muggles don't, such as Dementors.

A person's ability to perform magic may manifest itself in that person's infancy, spontaneously and without using supportive tools (like a wand). This usually only happens in moments of strong apprehension, fear or anger. For example, Harry Potter once made his hair grow back after a bad haircut, and made the glass front of boa constrictor's cage disappear. The Durlseys punished Harry for this, but didn't tell him why. Harry didn't learn the truth until Hagrid explained he was a wizard.

It should be noted that within the Harry Potter books the technical details of magic are, intentionally or otherwise, entirely obscure. Of Potter's lessons only those involving fabulous creatures, potions or astrology are given in any detail, none of the clearly magical lessons are shown with any structure. There is no mention of any underlying theory or process to magic. However, there are certain "rules" of magic, as if people could conjure whatever they need out of thin air, there would be no need to travel to Diagon Alley to buy things. One magical rule, for instance, is that it is impossible to awken the dead.

Table of contents
1 Terms
2 Magical Schools
3 Spells
4 The Dark Arts
5 Magical Objects
6 Magical Letters and Signs
7 Potions

Terms

Blood traitor

A derogatory term used to describe a wizard with "pure" blood who but refuses to mantain prejudice against "impure" peoples. Examples: The Weasleys (considered the most prominent blood traitors of England),
Andromeda Tonks (Née Black)

Half blood

A non-derogatory technical term used to describe the offspring of a wizard or witch and a Muggle or apparently a witch or wizard and a Muggle-born. Examples: Harry Potter, Lord Voldemort

Mudblood

A derogatory term used to describe a wizard or witch born to Muggle parents (the "polite" term is Muggle-born.) Examples: Hermione Granger, Lily Potter

Muggle

A term used by those who can use magic to refer to those who cannot. The term is usually used innocuously by most wizards and witches, but is also used in a derogatory way by some of the more evil characters: this is how Rowling suggests something analogous to racism. During Lord Voldemort's reign of terror, his Death Eaters performed many Muggle killings for the fun of it. In the middle ages, Muggles feared magical people, so now all the wizarding people in the world have chosen to remain hidden from Muggles for fear it could happen again. There some extremists who try to classify Muggles as "beasts" (rather than "beings"). Examples: Vernon Dursley, Petunia Dursley

An author named Nancy Stouffer sued Rowling for trademark infringement over her use of the term Muggles, but lost her case.

Pure blood

A term for a wizard or witch whose ancestors have possessed magical powers for untold generations. Many seek to keep this purity, and don't allow their children to marry anyone who is not pure blood. Since this makes for a limited number of choices, all the pure blood families are interconected. A pure blood who doesn't seek to keep the purity in their family is a blood traitor. Examples: Lucius Malfoy, Draco Malfoy, Neville Longbottom, Ginny Weasley

Squib

A term used to describe an individual of wizard heritage without magical powers. Though lacking magic, Squibs do have the power to see Dementors. Examples: Argus Filch, Arabella Figg

Magical Schools

Beauxbatons Academy of Magic

Durmstrang Institute

Hogwarts School of Witchcraft and Wizardry

Unknown School in Brazil

Unknown School in the United States

Spells

Spells, in the Harry Potter universe, seem to be enacted mostly by speaking a few words, typically in a modified form of Latin, and gesturing with a wand. Potionss are also in heavy use.

External link: Harry Potter Lexicon of Spells

Alohamora

This spell is used to open a locked door, window, etc. A person merly points their wand at what they want to open and say "Alohamora" and it will open. This spell can also open doors which have been magically sealed with the Colloportus spell. Doors can be magically sealed so that Alohamora can't open them, such as the door in the flying key, in Harry Potter and the Philosopher's Stone.

Colloportus

This spell can magically lock a door, preventing its opening for a presumably limited amount of time. It is easily countered by Alohomora, however.

The Fidelius Charm

This charm enables secret information to be hidden within a single living soul, or Secret-keeper. The information is then irretrievable until and unless the Secret-keeper chooses to reveal it; not even those who know the secret can tell it.

So far, there have been only two uses of the Fidelius Charm in the Harry Potter series. In Harry Potter and the Prisoner of Azkaban, it is explained that when Harry was an infant, he and his parents, Lily and James, were hidden from Voldemort with Peter Pettigrew as their Secret-keeper; Pettigrew betrayed them. In Harry Potter and the Order of the Phoenix, the charm is used to hide the headquarters for the Order of the Phoenix; Albus Dumbledore is the Secret-keeper, and is apparently able to give permission by letter to reveal the information. This implies that a direct, personal act is not required to bring a new person into the secret.

The root fidelis means trusty or faithful.

Expecto Patronum

This spell conjures a Patronus, a silvery phantom shape, usually that of an animal, which is the embodiment of the positive thoughts of the caster. A Patronus will drive away Dementors. Harry conjures a stag as his Patronus, while Hermione Granger conjures an otter. Cho Chang conjures a swan. In order to work, the person must concentrate on a happy memory, which is especially difficult in the presence of a Dementor.

Lumos

This spell creates a light that shines from the wand's tip, like a flashlight.

Nox

This spell turns off the light which is activated by the Lumos spell.

Wingardium Leviosa

To cause something to levitate, someone points their wand at what they want to levitate and says "Wingardium Leviosa" and it will rise into the air. When First Years learn this at Hogwarts, they practice with feathers.

The Dark Arts

While most magic is neutral, the Dark Arts are evil in nature. Students learn Defence Against the Dark Arts, to protect themselves from Dark wizards (unless they are being taught by Dolores Umbridge.) Draco Malfoy claims that in Durmstrang, they teach the dark arts themselves rather than how to protect one from them.

The Unforgivable Curses

Use of these curses on a fellow human could land you a life sentence in Azkaban.

Avada Kedavra

When this curse is performed, a green light is emitted from the wand of the curser, killing the victim. Arch-villain Lord Voldemort used this curse to dispose of his enemies, including Harry Potter's parents.

The term may come from the Arabic Abra Kadabra, meaning 'let the things be destroyed' or from the Aramaic abhadda kedhabhra, meaning 'disappear like this word'. Rather than being used as a curse, the phrase is believed to have been used as a means of treating illness.

Either of the original phrases may have brought into being the term Abracadabra. In common language, the word kedavra has evolved into cadaver, meaning dead body. But note also cadaver may come from Latin cadere, "to fall".

Cruciatus Curse

The Cruciatus Curse is started with incantation "Crucio". It inflicts intense pain upon the victim.

Several Death Eaters, including Bellatrix Lestrange (and presumably Barty Crouch Jr), used this curse on Neville Longbottom's parents in an attempt to get information on how Voldemort may be resurrected after his killing curse rebounded on him. They received no such information and were sent to Azkaban for their crimes, but the extensive torture drove Neville's parents insane.

Imperius Curse

The Imperius Curse starts with the incantation "Imperio" and gives the wizard complete control over his victim. The experience of being controlled by this curse is described as a complete, wonderful release from any sense of responsibility or worry over one's actions, at the price of one's free will. It is possible for the victim to fight the curse, however; the series protagonist, Harry Potter, is shown to be better than average in shaking this curse off.

Magical Objects

Floo Powder

Floo powder is a green powder used by Wizards to travel and communicate using fireplaces. The name comes from the word flue meaning the passageway which leads from a fireplace to the chimney so hot gasses can escape.

In the second book the Weasleys traveled to Diagon Alley using it; Sirius used it to communicate with Harry in the fourth book. In the fifth book, Dolores Umbridge and her Inquisitorial Squad inspected all incoming and outgoing Owl Post and every fireplace in Hogwarts except for Dolores Umbridge's own fire, so Harry had to put himself in considerable risk and use Umbridge's fireplace whenever he wanted to communicate with Sirius at headquarters, a method which was quite uncomfortable to begin with.

Howler

A Howler is a bright red letter usually signifying displeasure and anger from the sender directed at the recipient. When opened, the Howler begins to yell in the sender's voice at the recipient, eventually dissolving into scraps of paper. If not opened, it will explode and scream even louder.

The Marauder's Map

The Marauder's Map was created by Moony, Padfoot, Prongs and Wormtail as an aid in mischief-making. The map, at first glance, is a piece of blank parchment, but when the user says "I solemnly swear that I am up to no good" ink lines stretch across it, showing Hogwarts, and the location of everyone within the grounds. The map also gives information on how to open the secret passageways.

The map was given to Harry by Fred and George Weasley, who found it while unattended in Filch's office. The map made its first appearance in Harry Potter and the Prisoner of Azkaban.

In Harry Potter and the Prisoner of Azkaban, Snape finds the map in Harry's possession, and tries to force it to reveal its secrets; the map responds by insulting him. Snape suspects dark magic at work, though given that the map's creators, James Potter, Sirius Black, Remus Lupin and Peter Pettigrew, detested Snape, they may have added these insults specifically for him.

The Mirror of Erised

The Mirror of Erised is a mystical mirror that Harry discovers in one of the back corridors of Hogwarts School of Witchcraft and Wizardry, in Harry Potter and the Philosopher's Stone. On it is inscribed, erised stra ehru oyt ube cafru oyt on wohsi - I show not your face but your heart's desire, written backwards. When someone gazes into the mirror they see nothing more and nothing less than the deepest, most desperate desire of their hearts. Harry sees his parents standing beside him (he wishes to have a family). Ron sees himself as Head Boy and Quidditch Captain holding the Quidditch Cup (he wishes to be acknowledged). Dumbledore says he sees himself holding a pair of socks (for reasons as of yet unknown).

Pensieve

A Pensieve is a stone basin, covered in mystic runes, with a fluid or gas within. A wizard can place their memories into the basin when their mind is too flooded with information. One can more easily examine the patterns and interrelations of thoughts while they float in the Pensieve. The Pensieve also allows the user to fully immerse themselves in the memories stored within, much like a magical form of virtual reality. Tom Riddle's diary seems to have this same form of virtual reality.

Like many names in these books, pensieve is a pun: it is a sieve in that it is a device used for sifting out thoughts, and in using it one becomes pensive or thoughtful.

A Pensieve first appears in Harry Potter and the Goblet of Fire, and again in Harry Potter and the Order of the Phoenix.

Portkey

Portkeys are first mentioned in Harry Potter and the Goblet of Fire. Once created, they can be set to transport anybody who touches them to a designated location, or to "go off" at a pre-determined time and transport to that location anybody who happens to be touching it at the moment.

In Harry Potter and the Goblet of Fire, Barty Crouch Jr., who was masquerading as Alastor Moody, made the Triwizard Tournament cup into a portkey so it would transport anybody who touched it straight to the hands of Voldemort, expecting it would be Harry Potter. However, Harry grabbed the cup together with Cedric Diggory, who Voldemort unceremoniously got rid of immediately using Avada Kedavra.

Quidditch Balls and Equipment

There are several enchanted objects needed to play Quidditch, the most obvious being flying broomsticks. All the balls in the game are enchanted in some way. The Golden Snitch is enchanted to fly around and also to not leave the field. The Bludger is enchanted to fly around and try to knock players off their broomsticks. A Bludger does not focus on one player, unless it has been meddled with, as was the case in Harry Potter and the Chamber of Secrets. The Quaffle may appear an exception, but it is also enchanted to make it easy to grip, and so it falls more slowly than normal.

Remembrall

When you hold a remebrall, it turns red if you've forgotten something. Unfortunately, it does not tell you what you have forgotten.

The DVD of Harry Potter and the Philosopher's Stone contained a software approximation of a remembrall.

See also: Personal Digital Assistant.

The Sorting Hat

The Sorting Hat, in the Harry Potter series of novels by J. K. Rowling, is an artifact used at Hogwarts which magically determines which of the four school houses - Gryffindor, Hufflepuff, Ravenclaw or Slytherin - a new student should live in. As the students' names are read out loud alphabetically at the year's opening banquet the hat is placed on each of their heads in turn, and after a few moments' deliberation it announces its choice. The Sorting Hat was originally the hat of Godric Gryffindor. The hat assigned Hermione Granger, Harry Potter, and Ron Weasley to Gryffindor in their first year.

Before sorting the students each year the hat recites a new introductory rhyme. These rhymes occasionally warn of danger to come, as in Harry Potter and the Order of the Phoenix.

In Harry Potter and the Chamber of Secrets, the hat plays a critical role in the climax of the story by coming to Harry's aid in the Chamber and providing him with Godric Gryffindor's sword.

In the movie versions of the novels the hat's voice is played by Leslie Phillips.

Magical Letters and Signs

The Dark Mark

The Dark Mark is Voldemort's symbol, and is sent up in the air when any one of his followers makes a kill. It is also tattooed onto his faithful Death Eaters' left forearms. It comprises of a skull with a serpent in its mouth. According to Snape, the Dark Mark can be triggered by Voldemort to glow, causing pain to the Death Eaters, in order to signal them to apparate to meet him.

Letters

Witches and wizard can write words in the air with their wands.

Tom Riddle does at the end of Harry Potter and the Chamber of Secrets to show that I am Lord Voldemort is an anagram for Tom Marvolo Riddle.

Potions

Potions are created from mixing things together in a cauldron, to create something that is of some use. According to Snape, potions can "bewitch the mind, ensnare the senses and even put a stopper in death".

Draught of Living Death

The Draught of Living Death is made by mixing a root of Asphodel and an infusion of Wormwood. It brings upon its drinker a very powerful sleep that can last indefinitely, hence its name.

Veritaserum

Veritaserum has properties similar to a truth drug. Three drops can force the drinker to spill his innermost secrets. The name comes from the Latin veritas ("truth") plus serum.

Polyjuice Potion

Polyjuice Potions is used to tranform a person into the physical form of another person for one hour. The last ingrediate in this potion is piece of whomever the person wants to change into, ussually a hair. The potion doesn't work with animals. Harry, Ron and Hermione brewed this potion to turn into three Slytherins so they could sneak into the Slytherin Common Room and find out whether Draco Malfoy was the heir of Slytherin.

Barty Crouch Jr used Polyjuice Potion in Harry Potter and the Goblet of Fire in order to pose as Alastor Moody.