Shield Charm

"You wouldn't believe how many people, even people who work at the Ministry, can't do a decent Shield Charm."

- George Weasley regarding the charm

The Shield Charm (Protego) is a term applied to several varieties of charms. They create a magical barrier to deflect physical entities and spells, in order to protect a certain person or area. Conjurations may sometimes rebound directly off it back towards the caster or in other cases, may ricochet off in other directions or dissipate as soon as they hit the shield.

History
It's unknown who the inventor of the spell was and when it was invented. Harry Potter learned this spell in his fourth year, in preparation for the third task of the Triwizard Tournament. Harry also taught this charm to Dumbledore's Army during the 1995-1996 school, so the members would be able to protect themselves when the time came. This was also the subject of a question of the Theory of Charms O.W.L. in 1996.

This spell was used frequently during the Second Wizarding War, the Battle of the Department of Mysteries, the Battle of the Astronomy Tower, the Skirmish at Malfoy Manor, the Battle of Hogwarts, as well as on many other occasions.

Casting and effects
When cast, a (usually) invisible shield appears where the casters wand is pointed providing a protective barrier between themselves and their attacker. The shield itself does not give off light, but rather, the spell bouncing off of it does. The only spell the Shield Charm can't defend against is the Killing Curse, since it's unblockable.

The Shield Charm is a moderately difficult spell. Fred and George Weasley realised that most adult wizards, even those employed by the Ministry of Magic, could not produce a functional Shield Charm (something that not only could Harry Potter accomplish at age fourteen but, also impart to members of the D.A.). They used this to their advantage when marketing their line of protective clothing (hats, cloaks, etc.), upon which permanent Shield Charms were cast.

The incantation for the simplest Shield Charm spell is Protego.

Known Variations
[[File:Protegomaximahs.gif|thumb|250x250px|Horace Slughorn casting Protego Maxima

]]other varieties of the Shield Charm include as followed:
 * Protego Duo
 * Protego Horribilis
 * Protego Maxima
 * Protego Totalum

Harry Potter
"His Shield Charm was so strong Snape was knocked off-balance and hit a desk."

- Harry Potter's impressive mastery of the charm



Etymology
Latin protego, "I cover" or "I protect".

Behind the scenes

 * In the films, Shield Charms are used in nearly every duel shown, almost always used non-verbally and usually accompanied by a parry-like wand movement.
 * Also in the films, Shield Charms are shown to be able to deflect material objects such as arrows which were shot using a bow. Also it has shown to be able to withstand dragon fire from a Hungarian Horntail as seen in Harry Potter and the Deathly Hallows:Part 1 The Video Game.
 * The book depicts the Shield Charm as only being capable of repelling "minor to moderate curses and hexes", although Harry Potter uses it to block the worst effects of Antonin Dolohov's curse in the Department of Mysteries. However the film implies the Shield Charm to be significantly more powerful in that Harry is able to use it to completely deflect powerful curses cast by Voldemort himself.
 * In the early video games, Expelliarmus functions as a shield charm, due to a lack of enemies to Disarm. In these games, Protego is absent.
 * In the books Protego is also able to keep two quarrelling wizards from going at each other when a shield is cast between them.
 * In Harry Potter and the Deathly Hallows: Part 2, Protego is shown several times to be able to block the Killing Curse. Harry blocks multiple Killing Curses from Voldemort during their final duel and Bellatrix Lestrange blocks four Killing Curses while duelling Molly Weasley. According to the books this is incorrect as the Killing Curse is "unblockable" which is the main reason for its particular infamy, but within the context of the films the fact is never mentioned. As the Killing Curse would instantly end any duel if it were unblockable, this might just be done for dramatic effect and for longer duels.
 * In Harry Potter for Kinect Harry and Voldemort can use this spell against each other in the final battle during Voldemort's Last Stand as they engage in a normal duel.

Appearances

 * Harry Potter and the Goblet of Fire 
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (film)
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * Harry Potter and the Half-Blood Prince (video game)
 * Harry Potter and the Deathly Hallows
 * Harry Potter and the Deathly Hallows: Part 1
 * Harry Potter and the Deathly Hallows: Part 1 (video game)
 * Harry Potter and the Deathly Hallows: Part 2
 * Harry Potter and the Deathly Hallows: Part 2 (video game)
 * LEGO Harry Potter: Years 5-7
 * Harry Potter: Spells
 * Pottermore
 * Wonderbook: Book of Spells
 * Harry Potter for Kinect
 * Wonderbook: Book of Spells
 * Harry Potter for Kinect

Notes and references
Schildzauber Charme du Bouclier Encantamiento escudo Kilpiloitsu Protego Щитовые чары