I know this is probably a question that belongs elsewhere, but is there a canon or fanon official explanation on how the Protego spell works? is it just a momentary shield that comes up, a shield you hold in place? Spells it is weak against? Better alternatives? How it stops spells? I am just, for the first time, working on a oneshot, and wanted to work in a thing with protego. Thank you.

 

"protego" seems to be the catch all standard sheild of Fannon. It's a weak to moderate all purpose shield.

Cannon shows us it can stop some spells. That's all cannon shows.

 

It reflects some spells as well:

From Harry Potter and the Order of the Phoenix, when Harry attacks Bellatrix.

 

In fact, the Shielding Charm does work against physical objects as well. In DH, when Ron and Harry start fighting in the tent, Hermione casts the spell between them so they can't hurt each other; however when Ron storms out, she tries to hold him back but can't get past her own shield. She has to wait until it wears off on its own.

In short: physical beings and objects can't get through Shielding Charms. The Charm stops/reflects minor and medium-powered spells. It's limited in time. And you can't cancel it yourself.

 

Hmm.

My own personal theory about the shield charm (hint: the shield charm, not a shield charm) is that it's the only shield spell there is, but can manifest itself in a variety of different forms and strengths depending on how you cast it.

This seems to be backed by canon. We've seen "Protego" do different things at different times: block spells, reflect spells, block physical objects. Blocking and reflecting spells are obviously mutually exclusive effects, so it's clear that the one charm "Protego" has a variety of different forms, rather than every casting having all these properties.

With regards to Voldemort's "silver shield" in the OotP fight, it was my reading that that was a conjured physical shield made of silver (or looking like silver).

@Tinn: With the idea that you can't cancel the shield spell yourself, I'd say that it may be more likely that a scatterbrained Hermione (Fire? I haven't got any matches!) forgot to cancel it, rather than it being uncancellable. Given that we've seen a Protego charm (or variant of) being used as a ward-like spell, and also we know that it's possible to undo these types of protections with enough skill/time, it seems to indicate that you can undo Protego without overcoming it through sheer strength. If others can do it, why not the caster themselves?

 

That's pretty much what I've always been thinking about (magical) shields when reading the series.

I suppose a variety other magical defense techniques to fight off dark magic and curses exist, and one could call them shields as well, but the one charm used against offensive charms is Protego and its use depends on the caster and his intention.

 

It might mean variations of shields and what not, but it seems more reasonable that there are multiple ways of shielding.

Also, it would be weird if there's dozens of offensive curses and only one defensive.

 

Not as we see in canon, I think. Rather, it seems that the caster's skill/practice/intention with the spell changes its effect. See: Hermione putting the shield between Harry and Ron, with no mentioned alteration to the charm or wand movements. Also, before OotP Harry's Shield Charm can't stop a well-cast (by Hermione) Jelly-Legs Jinx; during DH he's stopping all kinds of curses (except the Unforgivables). It's unclear whether Crucio/Imperio et al are all unblockable, or just the Killing Curse. The Killing Curse was made unblockable, I seem to recall reading, as a bit of symbolism that "You can't stop Death". Unless you're the Master of Death; this may have been an attempt at a ret-con, I dunno.

In my opinion, the "advanced" shield charms used by Dumbledore and Voldemort in the atrium are either A: Extremely well-cast (perfectly cast, in fact, by Dumbledore) Shield Charms, B: counter-curses used to redirect or nullify, or C: conjured shields. They are not some kind of super-secret "Auror-level" charms, as fanon implies. I think that's the main point Taure's making, against all the fics that stole that kind of stuff from "Summer of Change" and many others before it, I'm sure (including my own first story, I'm man enough to admit).

 

I'd forgotten that Bellatrix's Protego sent Harry's Stunning spell back at him.

Two examples I'll use are somewhat different and lead me to believe, like Taure and kmfrank, that it's the caster's intent that changes how the spell manifests itself.

(1) In OotP, Bellatrix attempts to Summon the prophecy globe from Harry's hand, he shouts Protego, and the prophecy slides to the very tips of his fingers, but he does keep hold of it. Note that he never pointed his wand at anything, no shimmering whatever appeared, and he had the globe in his other hand. For me, that points to intent.

(2) During the Gringott's break-in fiasco in DH, Hermione casts Protego while looking up the tunnel along the cart tracks. This is just after they've been splashed with the Thieves' Downfall and the Polyjuice and Imperius are nullified. According to canon, a transparent shield (or similar description) rockets up the tunnel, and actually physically pushes through the aforementioned waterfall. I gathered from that passage that the shield would temporarily push or hold the other goblins back, and Hermione would be nowhere close to that spot, so there's no need to "hold" the shield in place or anything like that.

From those two examples as well as others, it seems to mme the intent is what matters in regards to the Shield Charm. As an aside, I believe that this also adds to the merits of the "intent matters more than mere words" debate, because there are two other spells in canon that begin with "Protego...", namely "Protego Horribilis" which is cast by Flitwick during the Hogwarts siege in DH, and "Protego Totalum", one of the various safety charms Hermione casts on their DH campsite every day. Obviously, if the words are all you need, as soon as "Protego" left your mouth, there'd be a Shield Charm up, regardless of what you said after.

 

I thought that was a major fucking cop-out by JKR.

Honestly, I was expecting "Protego Maximus!" in some scenes in DH.

 

I see nothing wrong with it. "Protego Maximus" would make less sense because "Maximus" implies simply a more powerful, complete shield spell, wheras from the examples and reasoning given previously the effectiveness and function of the spell depends on a given caster's skill and intent. However, "Protego Horriblis" and "Protego Totalum" both imply an expansion of the function of the spell: "Horriblis" as in the spell not only blocks, but does so agressively and dangerously to the blocked, and "Totalum" as in the spell covering a widerer and more comprehensive area, such as the entirety of the campsite as apposed to a single person or localised area.

 

Actually, in this case, it's forgiveable:

totalum is the accusative form of totalus (meaning "everything"). She was not saying "Total Protection," she was saying "Protect [all of this]".

I.e., she is specifying exactly what is to be protected by the shield. This is much like Wingardium Leviosa. Leviosa should be a sufficient "levitate" spell which anyone could cast on anything, and is shaped by intention. By specifying that it is to be cast on the feather, specifically, the spell is talored to making a feather float.

Since Ron didn't pay any fucking attention in the theory portion, he probably thought that the entire spell incantation was Wingardium Leviosa. Shows you that he's an idiot. However, his intention retalored an already talored spell to levitate the club over the troll.

 

Possible. Likely even.

However, it's possible that the full levitation spell is "Wingardium Leviosa", and rather than being "Float this feather" it's "float like a feather". Because the Latin in Potter spells is so dodgy, and not meant to be a literal translation of what the spell does, there's no way to tell.

 

Unfortunately, it will have to be left entirely to one's imagination. Wingardium Leviosa is entirely made up. There are no Latin words that begin (or at least, are spelled with) a W. Furthermore, ~osa is not a possible Latin word ending (or even possible at all in Latin), since part of the change from Italic to Latin was that all Ss inbetween two vowels turned into Rs (hence the reason behind opus (a work), and opera (two or more works). Thus, it should have been Leviora instead.

Interpretation is further confounded by how you interpret the ending of Wingardium. In Latin, adjectives follow the nouns they modify (tree tall and ball red - instead of tall tree and red ball). Furtermore, verbs follow their objects (A cat a mouse ate instead of A cat ate a mouse), so either Leviosa is supposed to be some form of the adjective, levis/leve, meaning "light" (maybe "as light as a ~"?); or, Wingardium is the object of the verb Levo (in a form that might mean "raise like a ~"?).

FUCK YOU ROWLING!

At least protego is an ACTUAL Latin word: it specifically translates as "I protect".

 

I see the point about it being the only shield, but that just doesn't make sense to me. Wouldn't shields designed specifically for certain spells be more effective? There is a limit to how much intent affects your spell, surely, or you could cast protego and have it turn into a sword to chop your enemy's head off. But after all, you can turn a pair of pants into a pair os shorts, but you can't turn them into a fleece sweater.

 

You're missing the point. Shields in HP don't work on scientific principles, they're more akin to metaphor and symbolism. So when you take the shield Protego as an example its meaning 'I protect' applies to everything. It will literally protect you from everything that could harm you, except for the notable example of Avada Kedavra, which symbolises the unstoppable nature of death.

Also, the Cruciatus Curse is blockable, Snape did it several times in HBP when Harry was chasing after him.

 

Blocking and parrying have often been referred to in canon; I've always wondered if they're actually the same thing as the Protego charm, merely using different words to describe the effect.

 

What could possibly be more effective than Protego, Summoning, Banishing and Conjuration? If you think your Protego can't stop it, create whatever the fuck you want to throw in the way of a spell, or someone something (or someone), and you're golden.

Or move out of the way.

 

But, for example, Dolohov's purple flame spell (DoM) still hurt Harry through the shield. Surely there is a shield meant for stopping say, impact spells, such as reducto, as versus a shield for stopping effect spells, like Leviosa or levicorpus.