Patronus Charm
In the
Harry Potter fantasy novels by
J. K. Rowling, a
Patronus is an insubstantial
animal form protector created by the advanced Patronus Charm
spell, and the only known means of defence against
Dementors and certain other
dark creatures.
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 â€" such as personal tragedy, or falling in love â€" 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.
Known Patronuses
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" (spelling may vary by book or edition; see
below). 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
O.W.L. 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.
The
Latin word
patronus means "protector" or "guardian" or (in archaic Latin) "father" (see
patronus). The plural of
patronus is
patroni, but the plural of the term as coined in the books is
Patronuses. The incantation for the charm is
Expecto Patronum. The Latin word
exspecto, or
expecto, means "I watch for", "I await", or (more rarely) "I require". The
Dog Latin phrase
ex pecto, which is pronounced identically, would mean "out of my heart" if it were grammatical. A rough translation of the incantation is thus "I summon a protector."
There is another latin verb
expecto meaning "I cast out from my chest" (from which
expectorate is derived) which may make sense in this case because the users are not awaiting their Patronus, they are literally casting it out.
