Patronus Charm



A Patronus is an insubstantial animal form protector created by the advanced Patronus Charm spell, and one way to defend against Dementors and certain other dark creatures.

Patronus
The Patronus Charm conjures an incarnation of the caster's innermost positive feelings, such as joy, hope, or the desire to survive, known as a Patronus. A Patronus can be viewed as the exact opposite of a Dementor. Even though it embodies all the positive emotions that a Dementor feeds on, a Patronus is conjured as a protector, and is a weapon rather than a feast: Patronuses shield their conjurors from Dementors, and even drive them away.

When conjured, a Patronus appears silvery, ethereal, and semi-transparent. Improperly formed Patronuses range from momentary formless bursts of silvery mist, to poorly-defined forms which are easily defeated or quickly dissipate on their own. A full-fledged (or corporeal) Patronus takes on a solid (if somewhat ethereal) fixed animal form that is appropriate and unique to the witch or wizard casting the charm; no two witches or wizards will conjure identical Patronuses. Patronuses summoned by a particular person always take the same form, although life-changing events — such as personal tragedy, or falling in love — can alter the form that one's conjured Patronuses will take from then on. This happened to Nymphadora Tonks when she fell in love with Remus Lupin.

The conjured Patronus protects the witch or wizard that summoned it, obeys his or her commands, and fades away shortly after it is no longer required.

The film and book versions of the Patronus have marked differences: in the books, Patronuses range from being an indistinct mist to fairly solid-looking animals. In the film adaptation of Harry Potter and the Prisoner of Azkaban, Harry's non-corporeal Patronus is more like a shield. Also, his corporeal Patronus, rather than running down the nearby Dementors, sends out a sort of omni-directional pulse, which drives the Dementors away.

Communications
As seen in the fourth and sixth books, and as revealed by the author before the latter, Albus Dumbledore has devised a method of using Patronuses to deliver messages. This offers great advantages in security, as Patronuses identify the caster and are Dark-proof; this means of communication is believed to be exclusive to the Order of the Phoenix.

Charm
The Patronus Charm is simple in theory, but hard to perform properly. The spell requires the use of a wand and the incantation "Expecto Patronum". Presumably specific physical gestures with the wand are also required but they are not mentioned specifically.

The caster assumes a very specific type of emotional state: he or she must tap into, and draw out, the positive emotions that will make up the Patronus, regardless of the situation. As the charm is used as a defensive spell at times of extreme duress and fear, this can be challenging. Dementors make things worse by evoking a person's negative emotions, making the Patronus Charm harder by their very presence. The best way is to concentrate on a very happy memory or thought. Harry Potter has successfully used both memories (such as the moment he learned of his magical heritage and that he would be attending Hogwarts), and pleasant wishes (such as visions of Dolores Umbridge being fired).

Because of the charm's advanced reputation, Harry impressed his Ordinary Wizarding Level examiners by demonstrating mastery of the spell, which was unusual for someone his age.

According to Fantastic Beasts and Where to Find Them, the Charm is also the only known defensive spell against Lethifolds: shroud-like creatures that silently slip into houses to suffocate and digest victims. Presumably there are also other Dark creatures against which the Patronus Charm is an effective defence.