Disarming Charm

"A handy (even life-saving) spell for removing an object from an enemy's grasp."

- Description of the charm

The Disarming Charm, also known as the Expelliarmus Spell or Disarming Spell (Expelliarmus) is a charm which forces whatever an opponent is holding to fly out of their hand. It is common to see this spell used in duels, to make an opponent release their wand. Multiple or exceptionally powerful Disarming Charms are even able to shove, knock down or send a target flying, sometimes to the extent of rendering a target unconscious.

History
It is not known precisely who created the Disarming Charm. Some wizarding historians claim that it may have been invented by Merlin himself, others claim that its first widespread use was in Madagascar in the 11th century. Even if any of this is true, the fact remains that it was not very popular until 1379, when Elizabeth Smudgling — the most likely inventor, in the opinion of Miranda Goshawk — used it in a duelling contest in Dartmoor.

It became Harry Potter's signature spell, and it notably caused the death of Lord Voldemort during the Battle of Hogwarts by rebounding his Killing Curse because the Elder Wand recognised Harry as its master through the spell connection, and thus strengthened the Disarming Charm to the point that Voldemort's curse backfired on himself.

Effects


The Disarming Charm causes whatever an opponent is holding at the time — usually a wand — to fly high out of their reach. It can also be used to intercept or rebound an opponents' spell while duelling, hence the life-saving effects of the charm.

The Disarming Charm appears as a jet of red light; indeed, this is one of the things that makes it recognisable before the effects of the charm are seen. Another notable effect of the charm is that if multiple charms are used on the same target, the target will be disarmed, but at the same time will be blasted backwards, as seen when Harry, Ron and Hermione all used the Disarming Spell at once on Severus Snape in the Shrieking Shack. Severus Snape himself used it more offensively during the only meeting of the Duelling Club against Gilderoy Lockhart, blasting him backwards with it.

Known uses and practitioners
"They made the most of the last few hours in which they were allowed to do magic before the holidays... and practised disarming each other by magic. Harry was getting very good at it."

- Fred, George, and the trio's last few hours before they return home for the holidays

Etymology
Latin expellere (ex = out, pellere = to drive), meaning "to drive out" and "arma" meaning "weapon". Expelliarmus actually means 'to drive out the weapon'.

Behind the scenes
"Then a blinding, jagged jet of white light flew through the air: Harry thought of lightning, but Snape had dropped to his knees and his wand had flown out of his hand"

- Dumbledore's use on Snape


 * This is the signature spell of Harry Potter.
 * In the later films, it is only when a witch or wizard is locked in the Priori Incantatem that the spell appears scarlet. When not locked in combat, it manifests as a bluish- white ball or flash of light, while in the second film, it appears as a golden fiery ring. The spell will either connect with the target's hand and force the wand out of their hand or will blast them off their feet, sometimes unconscious.
 * When Dumbledore used this on Snape in Chapter 33: The Prince's Tale, it appeared as white light similar to lightning, and hence was probably a variation of it rather than the spell itself, or else an entirely different disarming spell.
 * The charm is described in The Standard Book of Spells, Grade 2, and has a spellbook purely for itself.
 * In the video games, mainly he console versions of the first and second games, the Disarming Charm worked rather like a Shield Charm, rebounding an opponent's spells upon them. This is actually also the describing of the spell in the The Standard Book of Spells series. This was mainly due to the lack of being able to disarm in past video games.
 * However, the spell returned to its more offensive use by the Order of the Phoenix game, though the GBC version of the Chamber of Secrets game also follows this scheme.
 * Also in the console version of the second game, it's possible to catch and deflect spells not only cast by prefects in the PS2 version, but it's also possible to do so on one's own backfired spell. This only works on Flipendo and Incendio however, as the other projectile spells will pass through. In the case of the former, it moves rather fast so tight timing to activate the charm is needed.
 * The Disarming Charm is referenced on Doctor Who, when Shakespeare uses it to conclude a formula used to banish the villains from earth. The Doctor (played by David Tennant) smiles after the villains are beaten and says: "Good old J.K.", referencing the author of the Harry Potter series.
 * As seen in, it is possible to disarm and take ownership of one's wand without using the spell, as demonstrated by Harry, who forcefully disarmed Malfoy with his bare hands to take the latter's wand.
 * In the film versions of, Hermione Granger used the spell to make Mundungus Fletcher's wand fly over to her for her to catch it, which also happened when Harry Potter defeated Tom Riddle during Voldemort's Last Stand, in a similar way to the Summoning Charm.
 * The Disarming Charm is used, apart from depriving opponents of their wands, to intercept or rebound offensive spells. Usually, this only works with minor to moderate Dark charms, similar to the Shield Charm. The Elder Wand recognised Harry as it's true master through the spell connection, and thus strengthened Harry's spell to the point that even Voldemort's Killing Curse got rebounded upon himself.
 * Outside of cases of Priori Incantatem, the Disarming Charm is only able to intercept major Dark spells like the Killing Curse, similar to Stunning spells and the golden flame spell.

Notes and references
Encantamiento desarmador Expelliarmus Sortilège de Désarmement Aseistariisuntaloitsu Incantesimo di Disarmo Expelliarmus Экспеллиармус Expelliarmus