Spell Resistance

: Ron Weasley : "Hagrid did well, didn't he? How come all the spells bounced off him?"
: Hermione Granger: "It'll be his giant blood. It's very hard to Stun a giant, they're like trolls, really tough... but poor Professor McGonagall... four Stunners straight in the chest and she's not exactly young, is she?"
: — Discussion of Hagrid surviving multiple Stunning Spells[src]
The effects of spells could be resisted in certain circumstances. Wizards and witches may have had this trait naturally, as displayed by Harry Potter's and Bartemius Crouch Junior's resistance to the Imperius Curse. Magical creatures and beings such as giants and half-giants may also have had the natural ability to resist spells.
== Contents ==
* 1In magical creatures
* 2In wizards
** 2.1Magical protection
* 3See also
* 4Appearances
* 5Notes and references
== In magical creatures ==
: "Some charms will be ineffective on large creatures such as trolls, whose hides repel all but the more powerful spells."
: — Miranda Goshawk, The Standard Book of Spells, Grade 1[src]
:
Giants, dragons, Graphorns and trolls had considerable spell resistance, with hides that repelled all but the most concentrated and powerful spells, although they were still vulnerable to attacks on their eyes such as the Conjunctivitis Curse, possibly owing to the eyes being weak. It took almost half a dozen wizards to stun a dragon in preparation for the Triwizard Tournament. This attribute was also shared with half-giants, such as Rubeus Hagrid, who was able to resist repeated stunning in 1996.
Quintaped were able to resist Untransfiguration, as both the McClivert clan and the Department for the Regulation and Control of Magical Creatures tried in failure to turn them back into humans.
The natural resistance to certain spells was among the information contained on Creatures in the Folio Bruti. This was measured by a series of bars, one each for each combative spell being assessed by the book. The further to the right the bar was, the weaker that creature's resistance to that spell.
Dragon hide seemed to retain much of its protective power after the creature's death, and so was often made into protective gloves that could protect the wearer from hazards such as burning. A dragon-skin coat could make the wearer resistant to most spells.
Natural spell resistance could be overcome by shrinking a creature using a Shrinking Solution.
== In wizards ==
: "Look at that, you lot... Potter fought! He fought it, and he damn near beat it! We'll try that again, Potter, and the rest of you, pay attention — watch his eyes, that's where you see it — very good, Potter, very good indeed! They'll have trouble controlling you!"
: — Fourth year Harry resisting the Imperius Curse[src]
:
Strong mental capabilities were required when resisting some spells, which included resisting the Imperius Curse, the obscure art of Occlumency and nonverbal magic.
Young witches and wizards might often lose control of their magical skills when they were under emotional strain. This may have had a defensive use when in danger.
It is doubtful whether all spells could be resisted by a person of wizard blood only, such as the Stunning Spell, or any number of hexes and jinxes.
=== Magical protection ===
Shield Hats, Cloaks, and Gloves could grant the wearer resistance from minor to moderate hexes and jinxes, but would provide little defence against the Unforgivable Curses.
If somebody willingly gave their life for another person or people they would be protected. This was called sacrificial protection. This form of spell resistance only applied to spells from that individual.
Lily Potter willingly gave her life for her son Harry Potter, so when Voldemort sent a Killing Curse at the child it just rebounded and struck Voldemort, destroying his physical body and weakening him severely.
When Harry Potter gave his life during the Battle of Hogwarts, his friend Neville Longbottom should have died when Voldemort paralysed him and set him on fire, but Harry Potter's magical protection let him break free of the spell and kill one of Voldemort's Horcruxes, Nagini.