Magic in Harry Potter

In J. K. Rowling's Harry Potter series, magic is depicted as a supernatural force that can be used to override the usual laws of nature. Many fictional magical creatures exist in the series, while ordinary creatures sometimes exhibit magical properties. Magical objects are also described. Witches and wizards refer to the rest of the population, who are generally unaware of magic, as "Muggles" in the United Kingdom and "No-Maj" in the United States.

In humans, magic or the lack thereof is an inborn attribute. It is usually inherited and carries "dominant resilient genes". Magic is the norm for the children of magical couples and less common in those of Muggles. Exceptions exist: those unable to do magic who are born to magical parents are known as Squibs, whereas a witch or wizard born to Muggle parents is known as a Muggle-born, or by the derogatory term "Mudblood". While Muggle-borns are quite common, Squibs are extremely rare.

Rowling based many magical elements of the Harry Potter universe on real-world mythology and magic. She has described this as "a way of giving texture to the world". The books present the idea that the Muggle interpretation of these stories is a distorted version of what goes on in the wizarding world.

The magic of Harry Potter became the subject of a 2017 British Library exhibition and accompanying documentary. The exhibition, entitled Harry Potter: A History of Magic, is the first at the British Library to be inspired by a single series by a living author.

Using magic

Witches and wizards train to learn how to control their magic. With young and untrained children, magic will manifest itself subconsciously in moments of strong emotion: apprehension, fear, anger and sadness. For example, Harry Potter once made his hair grow back after a bad haircut, set a boa constrictor on his cousin Dudley at the London Zoo, and made Aunt Marge inflate to an enormous size. While this reaction is usually uncontrollable, as an untrained child, Tom Marvolo Riddle was able to make things move without touching them, make animals do what he wanted without training them, make "bad things happen" to people who annoyed him, or make them hurt if he wanted to. In addition, Lily Evans could guide and control a flower's blooming simply by wanting it to happen.

Almost all magic is done with the use of a wand. On the subject of wandless magic, Rowling says:

You can do unfocused and uncontrolled magic without a wand (for instance when Harry blows up Aunt Marge) but to do really good spells, yes, you need a wand.

A wizard or witch is only at their best when using their own wand. When using another's wand, one's spells are not as strong as they normally would be.

Spellcasting

Spells are the every-purpose tools of a wizard: short bursts of magic used to accomplish specialised tasks such as opening locks or creating fire. Casting usually requires an incantation, often in a modified form of Latin (see dog Latin), and gesturing with a wand. However, Rowling has revealed that particularly talented wizards can cast spells without the aid of wand, although magic produced with one is generally more precise and powerful. Spells can also be cast non-verbally, but with a magical wand. While most magic shown in the books requires the caster to use their voice, some do not (and this may depend on the witch or wizard). Dumbledore has been known to do impressive feats of magic without speaking.

It is possible to use a wand without holding it. In Order of the Phoenix, Harry performs lumos to light his wand when it is lying on the ground somewhere near him.

Spells are divided into rough categories, such as "charms", "curses", "hexes", or "jinxes". Although offensive and potentially dangerous curses exist in number, three are considered usable only for great evil, which earns them the special classification of "Unforgivable curses".

The limits of magic

Before publishing the first Harry Potter novel, Rowling spent five years establishing the limitations of magic – determining what it could and could not do. "The most important thing to decide when you're creating a fantasy world," she said in 2000, "is what the characters can't do." For instance, while it is possible to conjure things out of thin air, it is far trickier to create something that fits an exact specification rather than a general one; moreover, any objects so conjured tend not to last.

Death

Rowling has described death as the most important theme in the novels. As Dumbledore states in Harry Potter and the Goblet of Fire, there is no spell that can truly and permanently bring the dead back to life. While corpses can be transformed into obedient inferi on a living wizard's command, they are little more than zombies, with no soul or will of their own. However, there are some methods of communicating with the dead, though with limited results. For example, all Hogwarts headmasters appear in a portrait when they die, allowing consultation by future generations, however the portrayal is a reflection of the who the wizard was, not a link to the actual current state of the deceased. It is also possible through a rare priori incantatem side-effect to converse with ghost-like "shadows" of people magically killed with that wand. The Resurrection Stone also allows one to talk to the dead, but those brought back by the stone are not corporeal, nor do they wish to be disturbed from their peaceful rest. In Harry Potter and the Chamber of Secrets, Tom Riddle’s diary was able to bring his memory back, but once the diary was destroyed, the memory was also. Throughout the series, this limit is continually mentioned, and wizards who try to surpass it most often create magical disasters instead.

Likewise, it is not possible to make oneself immortal unless one makes use of an object of great power to sustain life, such as the Philosopher's Stone or Horcruxes. If one were to possess the three Deathly Hallows, it is fabled that they would possess the tools to become the "master of death". However, it is hinted that to be a true "master of death" is to be willing to accept that death is inevitable. Other methods of extending life include drinking unicorn blood, which will keep a person alive even if death is imminent, but at the terrible price of being cursed forever. Being magical can contribute to one's longevity, as there are several characters in the series who are unusually long-lived. It is revealed by Nearly Headless Nick in the fifth book that all witches and wizards have the choice of becoming ghosts upon dying; however, it is described as "a pale imitation of life". Snape states that a ghost is merely "the imprint of a departed soul left upon the earth".

Death is studied at the Department of Mysteries in a chamber containing an enigmatic veil, which Rowling has described as "the divide between life and death". With regard to what is on the other side, she elaborated: "Do I believe you go on? Yes, I do believe you go on. I do believe in an afterlife, although I'm absolutely doubt-ridden and always have been."

Principal exceptions to Gamp's Law of Elemental Transfiguration

The principal exceptions to Gamp's Law of Elemental Transfiguration is a precept of magical theory mentioned by Hermione and later repeated by Ron in the final book. She explains that nutritious food is one of these: Witches or wizards can cook and prepare food using magic, and even multiply it, but not create it out of nothing.

There are numerous examples in the series of food seeming to have been conjured from nothing, such as when ingredients suddenly materialize in pots in Molly Weasley's kitchen, and when Professor McGonagall creates a self-refilling plate of sandwiches for Harry and Ron in Chamber of Secrets. In all cases, these events can be reasonably explained as food either being multiplied, or being transported from elsewhere. An example of the latter is the explanation given for banqueting at Hogwarts: The food is prepared by house elves in the kitchens below and then laid out on four replica tables, directly below the actual house tables in the Great Hall. The elves then magically transport the food from the replica tables up to the house tables at once (serving all the students simultaneously rather than requiring some to wait while others already have their meals).

The dining hall is the only apparent exception to Gamp's law explicitly mentioned in the series, but explained as magical transportation, not creation ex nihilo. However, Rowling herself has stated once in an interview that (genuine) money is something wizards cannot simply materialize out of thin air, or the economic system of the wizarding world would then be gravely flawed and disrupted. While the Philosopher's Stone does permit alchemical creation of gold, the stone is portrayed as an extremely rare, even unique object.

Emotion

As explained earlier, young untrained wizards can trigger uncontrolled magic when they are in the state of intense emotion. But emotions also affect trained witches and wizards and their magical abilities. For instance, in Half-Blood Prince, a heartbroken Nymphadora Tonks temporarily loses her power as a Metamorphmagus when Remus Lupin starts distancing himself from her; the form of her Patronus changes to reflect her depression. Another example is Merope Gaunt, who only demonstrated any magical ability when removed from her father's oppression, but then lost it again when her husband abandoned her.

Several magical spells require the use of certain emotions when casting them. The Patronus charm, for example, requires the caster to concentrate on a happy memory. Another example is the Cruciatus Curse, which causes immense pain; as Harry discovers during a duel with Bellatrix Lestrange, effective use of this forbidden dark magic requires sadistic desires.

Love is depicted as a particularly powerful form of magic. According to Dumbledore, love is a "force that is at once more wonderful and more terrible than death, than human intelligence, than forces of nature". Lily's voluntary sacrifice on Harry's behalf saves him from Voldemort as a baby, and Harry makes a similar sacrifice to save his friends at the end of Deathly Hallows. A certain key prophecy in the series describes Harry as having "power the Dark Lord knows not", referencing his capacity for love.

True love is impossible to create magically; Amortentia, a love potion, can only create a powerful sense of infatuation and obsession.

Magical abilities

The following is a list of special abilities that a wizard or witch in the Harry Potter universe may have.

Animagi

An animagus is a witch or wizard who can turn into a particular animal at will. This ability is not innate: It must be acquired by magical means. All British animagi must, by law, register at the Ministry of Magic, though a number of characters are revealed over the course of the series to have illegally remained unregistered: James Potter, Sirius Black, Peter Pettigrew, and Rita Skeeter. Minerva McGonagall is a Ministry-registered animagus taking the form of a cat.

Each animagus has a specific animal form, and cannot transform into any other animal. The animal cannot be chosen: It is uniquely determined by that individual's personality.

Animagi transformation can be performed wandlessly. Sirius and Peter are left wandless for over 10 years, but both retain the ability with no apparent difficulties. When animagi transform they take on the appearance, not necessarily all traits, of a normal animal. In Harry Potter and the Prisoner of Azkaban, it is noted that Ron's pet rat Scabbers (later revealed as Peter Pettigrew's animagus form) has lived over twelve years, when a genuine rat would only live about three. Also, an animagus in animal form retains the ability to think like a human, which is the principal difference between being an animagus and being transfigured into an animal.

Explicit emphasis is placed in the books on the differences between animagi and werewolves. Animagi have full control over their transformations and retain their minds, whereas werewolves' transformations are involuntary and include severe changes in personality. After the person has transformed into a werewolf "... he no longer remembers who he is. He'd kill his best friend. The werewolf only responds to the call of his own kind." The only way that a werewolf can retain their sanity, intelligence, and memory while transformed is using the Wolfsbane potion.

Metamorphmagi

A metamorphmagus is a wizard who can change their appearance at will. Nymphadora Tonks and her son, Teddy Lupin, are the only living metamorphmagi mentioned in the novels. At various points, Tonks changes her hair colour and style according to her mood. She is a relatively young woman, but she occasionally chooses to appear elderly.

Parseltongue

Parseltongue is the language of snakes. Those who can speak parseltongue are called parselmouths. The ability is rare; the only parselmouths mentioned in the novels are Harry, Voldemort, Salazar Slytherin and Slytherin's descendants. Rowling said she derived the term "parselmouth" from "an old word for someone who has a problem with the mouth, like a hare lip".

Seers

A seer is a witch or wizard with the clairvoyant ability to foresee future events. The predictions given through this ability can sometimes be self-fulfilling prophecies, and Dumbledore states in Order of the Phoenix that not all of them come true, depending on the choices made by those involved. This would seem to indicate that a seer predicts possible or likely events, at least in some cases.

In the Hall of Prophecy at the Department of Mysteries, thousands upon thousands of glass spheres are imbued with records of prophecies made by seers. Only a person mentioned in a prophecy can safely retrieve it; anyone else who tries to do so will be driven insane.

According to McGonagall, true seers are extremely rare. Sybill Trelawney is the only seer portrayed in the books, and is considered an "old fraud" by her students – although it is mentioned that Sybill's great-great-grandmother, Cassandra Trelawney, was a renowned Seer in her day. Trelawney is ultimately sacked by Dolores Umbridge in the fifth book for her lack of ability. She has twice made true prophecies – both significant to Harry Potter – but had no recollection of either prediction afterward.

Legilimency and occlumency

Legilimency is the practice of extracting feelings and memories from another person's mind – a form of magical telepathy. It also allows the practitioner to convey visions or memories to another person. A wizard possessing this skill is called a legilimens, and can, for example, detect deceit in another person, witness their memories, or plant visions in their mind. The counter-skill to legilimency is occlumency, which is practised by an occlumens. It can be used to prevent a legilimens from discovering the practitioner's thoughts or memories. Voldemort, Severus Snape, and Albus Dumbledore are all skilled in legilimency and occlumency.

Apparition

Apparition is a magical form of teleportation, through which a witch or wizard can disappear ("disapparate") from one location and reappear ("apparate") in another. It is usually accompanied by a cracking or popping sound, though the more skilled wizards such as Dumbledore can apparate "so suddenly and silently" that they seem to have "popped out of the ground". According to Harry, apparition is also accompanied by a very unpleasant squeezing sensation, as though being sent through a tight rubber tube.

The Ministry of Magic licenses apparition. A witch or wizard must be 17 years old, or older, and have a license to apparate as a means of transportation in much the same way real-world governments require individuals to have a license to drive a motor vehicle. Students at Hogwarts may attend Ministry-administered apparition lessons during their sixth year, and take their examination once they turn seventeen. The books depict apparition as possible, although illegal, without a license, but it is usually not done (except by special permission during lessons). Harry illegally apparates without a license in Deathly Hallows but, since his magical trace was at that point lifted, the Ministry is likely unaware that he does it.

Learning to apparate is difficult, and students run the risk of splinching – being physically split between the origin and destination – which requires the assistance of the Ministry's Accidental Magic Reversal Squad to properly undo although essence of dittany can also mend certain wounds. Splinching is quite common during lessons, and can be uncomfortable (and at times rather gruesome) depending on the body parts splinched, but is ultimately harmless if promptly and properly reversed.

Writing in the books indicates that the characters consider it uncouth to apparate directly into a private area, such as a home. Dumbledore states in Half-Blood Prince that it would be "quite as rude as kicking down the front door". For this reason, and for reasons of security, many homes have anti-apparition spells protecting them from uninvited intrusions. The accepted way to travel to a home is to apparate to a nearby location, and continue to the final destination on foot. Apparition is considered unreliable over long distances, and even experienced users of the technique sometimes prefer other means of transport, such as [[Broomsticks in /ref> In one example, Tonks changes her face by reshaping her nose into "a beaklike protuberance like Snape's", to "something resembling a button mushroom", and "one like a pig snout" which reminded Harry of his cousin Dudley.Harry Potter|broomstick]]s. Rowling has stated that apparating over long distances depends on the skill of the wizard, and "Cross-continental apparition would almost certainly result in severe injury or death." Indeed, even the prodigiously skilled Lord Voldemort elects to fly back to England after visiting the far distant Nurmengard.

For reasons of security, the grounds and buildings of Hogwarts are protected by ancient anti-apparition and anti-disapparition spells, which prevent humans from apparating on the school grounds. There is also a spell that prevents individuals from disapparating, which Dumbledore places on the Death Eaters captured at the Ministry of magic in Order of the Phoenix; a sister spell, which allows one to apparate into a location but prevents them from disapparating out of it, is cast by the Death Eaters in Hogsmeade in combination with the caterwauling charm. Dumbledore is the only person who can both apparate and disapparate from the school grounds, since he is the headmaster, and then only from certain locations, such as the top of the astronomy tower, which presumably protrudes above the domain of the anti-apparation charm.

A witch or wizard can use side-along apparition to take others with them during apparition. Dumbledore successfully transports Harry this way several times in Half-Blood Prince, and Harry's first non-lesson attempt at the skill is the side-along apparition with the weakened Dumbledore when they return from the seaside cave.

In the books, the words "apparate" and "disapparate", like many other neologisms used by Rowling, are capitalised, whereas established English words such as "jinx" and "hex" are not. The words themselves are most likely derived from the French apparaître and disparaître, meaning 'to appear' and 'to disappear'. Another possible derivation is from the English word "apparition", meaning "a supernatural appearance of a person or thing; anything that appears, especially something remarkable or startling; an act of appearing", which comes from the Latin "apparitio", meaning attendance. "Disapparate" probably comes from the same word but with the prefix "dis-" expressing negation or reversal.

Other teleportation

Some magical creatures have their own forms of instantaneous travel, such as a house elf's ability to teleport or a phoenix's ability to appear and disappear in a burst of flame. Unlike wizards, elves are not restricted by anti-apparition magic. Dobby, Kreacher, and the rest of the house-elf population can apparate within the Hogwarts grounds, as they demonstrate on multiple occasions, most notably when Dobby visits Harry in the hospital wing, and when Harry summons Dobby and Kreacher and assigns them to tail Draco Malfoy. Fawkes disapparates from the headmaster's office at Hogwarts along with Dumbledore when the latter evades arrest at the hands of Ministry officials in Order of the Phoenix.

Some magical devices like the Floo Network, Portkeys and Vanishing Cabinets also provide forms of magical teleportation.

Veela charm

An ability attributed to veela and those of veela heritage, such as Fleur Delacour, veela charm is used to charm males, much as the sirens do in The Odyssey. Men who are exposed to it over time become more resistant to it, although the veela charm takes full effect if the veela surprises the man, as noted by Ron in Half-Blood Prince.

As shown in Goblet of Fire, one can use veela hair as cores in magical wands. According to famed wandmaker Mr. Ollivander, these wands are "a little temperamental".

Magical resistance

Powerful creatures such as trolls, dragons, and giants may exhibit magical resistance – a certain degree of immunity against hexes and spells. Hagrid is resistant to certain spells (like the Stunning spell) due to being half giant. This type of resistance is not insurmountable; if enough Stunning spells, for example, are fired simultaneously at a creature with magical resistance, the creature may still be rendered unconscious. Also, wizards and witches can resist certain spells with the power of their own magic-enhanced will, as Harry does in Goblet of Fire, when Barty Crouch Jr. (disguised as Alastor Moody) tries to control Harry with the Imperius Curse and Harry resists. The same book shows Barty Crouch Sr. throwing off the Imperius Curse after spending several months under it.

Spell-like effects

Unbreakable vow

The unbreakable vow is a voluntary agreement made between two witches or wizards. It must be performed with a witness ("bonder") on hand, holding their wand on the agreeing persons' linked hands to bind them with magic as a tongue of flame. The vow is not literally "unbreakable" as the person taking it is still able to go back on his or her word, but doing so will cause death. The Unbreakable Vow was first introduced in Half-Blood Prince, in which Snape made a promise to Narcissa Malfoy to protect Draco, with Bellatrix as the "bonder", as her son attempted to fulfil a task set by the Dark Lord, and for Snape to fulfil the task if Draco fails. Another example in Half-Blood Prince occurs when Ron tells Harry how Fred and George tried to make him undertake an unbreakable vow when he was too young to know what it meant, but because of their father's indignant intervention, they did not complete it.

Priori incantatem

Priori incantatem (from Latin: priorem incantatum – "previous incantation"), or the reverse spell effect, is used to display the spells cast by a wand. The spells cast by the wand will emerge in smoky or ghost-like replicas in reverse order, with the latest spell emerging first. It is first encountered in Goblet of Fire when Barty Crouch Sr.'s house elf Winky is caught holding Harry's wand. This spell is used to reveal that it was indeed Harry's wand (that was used by Crouch's son) that cast the Death Eaters' dark mark. In Harry Potter and the Half-Blood Prince, it is revealed that the teenage Voldemort murdered his father and grandparents using his uncle Morfin's wand, knowing that, when examined, the wand would incriminate Morfin as the murderer. In Deathly Hallows, Harry fears that a priori incantatem spell will be used on Hermione's wand after the Death Eaters get hold of it. This would reveal that she had accidentally broken his holly-and-phoenix-feather wand when a curse misfired when they both narrowly escaped Voldemort earlier. As a result, the protection of the shared cores was lost and, worse still, this would now become known by Voldemort. During the final duel between Harry and Voldemort, the latter mentions that he knows that the holly and phoenix wand is destroyed, implying that the priori incantatem has indeed been performed on Hermione's wand, as they had feared.

Forcing two wands that share the source of their cores to battle can unintentionally cause a potent form of priori incantatem. The tips of the two wands will connect, forming a thick golden "thread" of energy, and the two wands' masters fight a battle of wills. The loser's wand will regurgitate shadows of spells that it has cast, in time reverse order. This side-effect occurs during the duel between Harry and Voldemort at the end of Goblet of Fire. Their simultaneous, contrary spells (Harry casts expelliarmus and Voldemort casts avada kedavra) trigger the threads, and as Voldemort loses the battle of wills, his wand regurgitates, in reverse order, echoes of the people his wand had most recently murdered: Cedric Diggory, Frank Bryce, Bertha Jorkins, and later Harry's parents.

Dark Arts

The Dark Arts are magical spells and practices that are usually used for malicious purposes. Practitioners of Dark Arts are referred to as Dark Wizards and Dark Witches. The most prominent of these is Voldemort, known to them as the Dark Lord. His followers, known as Death Eaters, practice the Dark Arts while doing his bidding.

The type of spells characteristic of Dark Arts are known as curses, which usually cause harm to the target. All, to a certain degree, are in some circumstances justifiable. The motivation of the caster affects a curse's result. This is most clearly outlined for the Cruciatus curse: When cast by Harry, angered by the death of his godfather at Bellatrix's hands and desiring to punish her, it causes a short moment of pain. As Bellatrix herself comments, righteous anger does not allow the spell to work for long. When cast by figures such as Voldemort, who desire to inflict pain for its own sake, it causes intense agony that can last as long as the Dark witch or wizard persists.

Use of Dark Magic can corrupt the soul and body; Voldemort has used such magic in his quest to prolong his life and obtain great power. The Dark Arts also cause Voldemort to look deformed and inhuman, a side effect of splitting his soul into Horcruxes.

According to Snape, the Dark Arts "are many, varied, ever-changing and eternal ... unfixed, mutating, indestructible". In magical dueling, there are any number of spells that may be used to attack, immobilise, or disarm an opponent without causing pain or lasting harm; however, spells such as the Cruciatus Curse wound or seriously distress a victim in some way. Dark spells can be classified into three groups: Jinxes, hexes, and curses.

In the wizarding world, use of the Dark Arts is strongly stigmatised and extreme forms are illegal; however, these spells are prevalent enough that even before the rise of Voldemort, many schools (including Hogwarts) taught Defence Against the Dark Arts as a standard subject. Techniques include anti-curses and simple spells to disable or disarm attackers, or fight off certain creatures. Some schools, such as Durmstrang, teach Dark Magic. A Dark Arts class is also taught at Hogwarts while it is under Death Eater control.

Unforgivable curses

The Unforgivable Curses is a wizarding law category for the three worst known spells of the Dark Arts. They were first so-classified in 1771. These curses are used by the books' villains, such as Voldemort and the Death Eaters, and in some cases the Ministry of Magic; their use inspires horror and fear among other magical persons. They are so-named because their use is legally forbidden and unpardonable in wizarding law, and is punishable by a life sentence in Azkaban. The only exception is if a person is proven to have done them under the influence of mind control. These curses are thus normally used secretly.

• The killing curse (incantation: avada kedavra) manifests as a jet of green light that causes immediate death. The killing curse has no cure, and cannot be blocked by most magical means. However, it can be blocked by love (e.g. Lily Potter giving up her life for her son created a reflex charm that defeated it, but since she died, how she did it is not known); further, the green energy bolt is shown as being dodged, blocked by solid objects, and deflected with a few other powerful and fast spells, in particular stunning spells.

• The cruciatus curse (incantation: crucio, Latin for "I torture") causes the victim intense pain and is used for torture, but does not physically harm them. The strength of the curse is determined by the person who cast it. It was used regularly by the Death Eaters. The curse can torture a person to the point that they are exhausted to death, or in a more sadistic case, it causes permanent amnesia and insanity. Effective casting requires the caster to have sadistic desires. It is shown as a bright-faded blue light (though it is usually invisible or even a red bolt of light in the films).
• The imperius curse (incantation: imperio, Latin for "I command") is used for mind control or hypnosis, and can force the victim to do things they would normally be unwilling or unable to. The strength and duration of the curse depends on the caster, as well as the level of resistance by the victim. The curse is shown as a bright haze. (It was depicted as either invisible, or a green, mist-like haze in the films.)

The use of the unforgivable curses was authorised against Voldemort and his followers by Bartemius Crouch Sr., during the First Wizarding War. (Shortly after his reincorporation, Voldemort names two Death Eaters "killed by aurors".) In addition, in Deathly Hallows, the unforgivable curses are used liberally by protagonists, ranging from Professor McGonagall with the imperius curse, to Harry effectively using both the imperius and cruciatus curses. He uses the imperius curse on a goblin and a suspicious Death Eater during a disguised attack on Gringotts Bank, and Dolores Umbridge during an incursion into Ministry of Magic, while it was under control of the Death Eaters.

Dark Mark

The Dark Mark is the symbol of Voldemort and the Death Eaters and takes the form of a skull with a snake coming out of the mouth in place of a tongue. The mark is cast into the sky by Death Eaters whenever they have murdered someone. Morsmordre is the spell to conjure the Mark. It first appears in Goblet of Fire and is described as a "colossal skull, composed of what looked like emerald stars, with a serpent protruding from its mouth like a tongue". Once in the sky it was "blazing in a haze of greenish smoke". Dark Marks are also branded on the left forearm of the closest followers of Voldemort. The mark serves as a connection between Voldemort and each who bears it; he can summon them by touching his mark, causing it and those of his followers to burn and change colour. Death Eaters can summon Voldemort in the same fashion. Following Voldemort's ultimate defeat, the Dark Marks on his Death Eaters fade into a scar "similar" to Harry's. In the books, the Dark Mark is described as green; however, in the films, it was only green at the Quidditch World Cup. In all other film appearances it has been grey.

Inferius

Not to be confused with Infernus.

An inferius (plural: inferi) is a corpse controlled by a dark wizard's spells. An inferius is not alive, but a dead body that has been bewitched into being a puppet for the witch or wizard; this is depicted in the films as a white mist in the controlled corpse's eyes. The inferi do not think for themselves: They are created to perform a specific duty assigned by the dark wizard who commands them, and as seen in the inferi guarding Voldemort's horcrux in a seaside cave, remain idle until their task to be performed is triggered. The task is then thoughtlessly carried out per the prior direction, whether or not it will produce any result. Inferi are difficult to harm by magic; however, they can be repelled by fire or any other forms of heat or light, as the inferi in Voldemort's cave are. When defeated but not destroyed, they return to their idle state.

Inferi are considered dangerous and frightening enough by the magical world that impersonating an inferius (as Mundungus Fletcher is reported to have done in Half-Blood Prince) is an offense worthy of imprisonment in Azkaban.

The Ministry of Magic fears that Voldemort is killing enough people to make an army of inferi: As they are dead, they are very difficult to stop. When Voldemort was hiding one of his horcruxes in the past, he filled a lake in a cave with many inferi, which were to attack and drown anyone but Voldemort who came into the cavern and took the locket. When Harry and Dumbledore took the locket, the inferi attacked Harry; Dumbledore repelled them with a rope of magical fire. It is also revealed that the inferi almost killed Kreacher after he drank from the basin to help Voldemort hide his horcruxes, but having been ordered to return to his master after his task with Voldemort was complete, he managed to apparate out of the cave. These inferi later killed Regulus Black when he stole the horcrux and ordered Kreacher to destroy it.

Horcrux

See also: Magical objects in Harry Potter § Horcruxes

A horcrux is an object created using dark magic to attain effective immortality. The concept is first introduced in the sixth novel, Harry Potter and the Half-Blood Prince, although horcruxes are present in earlier novels without being explained or identified as such.

To create a horcrux, a witch or wizard must first prepare the chosen object in a ritual which Rowling described only as "too horrible to go into detail about". Following the preparation of the object, the witch or wizard must then take a life, an act which splits the soul. Following that, further dark rituals are required in order to remove the soul shard from the maker and place it into the prepared object. Once this is done, the horcrux becomes magically protected from almost all forms of destruction, requiring extremely powerful magic or especially destructive substances to do so.

Ordinarily, when one's body is killed, the soul departs for the next world. If, however, the body of a horcrux maker is killed, that portion of his soul which was still in his body will not pass on to the next world, but will rather exist in a non-corporeal form capable of being resurrected by another wizard. If all of someone's horcruxes are destroyed, then his soul's only anchor in the material world would be his body, the destruction of which would then cause his final death. To destroy the horcrux, the destroyer must destroy it in such a way that it is put beyond magical repair. In the second book, Tom Riddle's diary (later found to be a horcrux) is destroyed by Harry with a basilisk's venomous fang. In the seventh book, Gryffindor's sword, which is impregnated with basilisk venom, an old basilisk fang, and fiendfyre are the substances used to destroy them.

Magic at Hogwarts

Main article: Hogwarts § Subjects

At Hogwarts, students must study a core group of subjects for the first two years, after which they must choose between several electives in addition to the core subjects. Transfiguration, Defence Against the Dark Arts, Charms, Potions, Astronomy, History of Magic, and Herbology are compulsory subjects for the first five years, as well as flying lessons for the first year, which becomes optional for the remaining six years. At the end of their second year, students are required to add at least two optional subjects to their syllabus for the start of the third year. The five choices are Arithmancy, Muggle Studies, Divination, Study of Ancient Runes, and Care of Magical Creatures.

Portraits

In the Harry Potter series the subjects of magical portraits (even those of characters that are dead) can move, interact with living observers, speak and demonstrate apparent emotion and personality. Some can even move to other portraits to visit each other, or relay messages, or (if more than one painting of the subject exists) move between separate locations by way of their portraits. An example of this is Phineas Nigellus Black, who has a portrait in the headmaster's office to offer advice to the current headmaster.

Portraits are enchanted to move by the artist, but the degree to which they can interact with others depends on the power of the subject. Rowling has commented that a portrait is merely a faint imprint of the deceased subject, imitating their basic personality and thought patterns. They are therefore "not as fully realised as ghosts".

Portraits in the Headmaster's office

The portraits in the Headmaster's office depict all the former Heads of Hogwarts, with the exception of Dolores Umbridge. They advise the Headmaster and are "honour-bound to give service to the present headmaster" (according to Armando Dippet). Rowling has explained that portraits of past headteachers tend to be more realistic than most, as the subject in question usually imparts knowledge and teaches them how to behave before their death. The portrait of Snape was installed in the Headmaster's Office at Harry's request.

Photographs

Wizarding photographs of people have similar properties to magical painted portraits: The figures within move about or even sometimes leave the frame. They appear in wizard newspapers and other print media, as well as on Chocolate Frog cards. Colin Creevey mentions in Chamber of Secrets that a boy in his dormitory said that if he develops the film from his Muggle camera "in the right potion", the pictures will move. However, unlike portraits, figures in wizarding pictures cannot speak and display little sentience. It appears that they do have some knowledge of current events, as in Order of the Phoenix, the family photograph on Arthur's desk shows everyone except Percy "who appeared to have walked out of it".

Further reading

• Highfield, Roger (2002). The Science of Harry Potter: How magic really works. New York: Viking. ISBN 978-0-670-03153-5.
• Teare, Elizabeth (2002). "Harry Potter and the technology of magic". In Whited, Lana A. (ed.). The Ivory Tower and Harry Potter: Perspectives on a literary phenomenon. Columbia, Missouri: University of Missouri Press. pp. 29–342. ISBN 978-0-8262-1549-9.
• Black, Sharon (2003). "The Magic of Harry Potter: Symbols and Heroes of Fantasy". Children's Literature in Education. 34 (3): 237–247. doi:10.1023/A:1025314919836. ISSN 0045-6713. S2CID 162551714.