Sacrificial protection

Sacrificial Protection
Incantation	None
Type	Counter-charm
Hand movement	Deliberately shield target with body from intended curse
Light	None
Effect	Powerful and long-lasting counter-charm

"Your mother died to save you. If there is one thing Voldemort cannot understand, it is love. He didn't realise that love as powerful as your mother's for you leaves its own mark. Not a scar, no visible sign... to have been loved so deeply, even though the person who loved us is gone, will give us some protection forever."

— Dumbledore regarding the power of love

Sacrificial protection is an ancient, powerful, and long-lasting counter-charm. This charm unlike others has no incantation and is endowed when one person (whom we will call "the victim" for purposes of this article) ultimately sacrifices his or her own life willingly and out of deep and pure love to save the life of one or more people (to whom this article will refer as "beneficiaries").

When the person to make the sacrifice dies, the counter-charm is so powerful that the murderer can not physically touch the intended victim, as the protection lives on in their veins. Also, any spells cast on the beneficiaries wear off quickly.

Requirements

In order for the protection to form, the victim must be given the option to live, but consciously choose death. This is why James Potter's death did not confer magical protection on Lily and Harry in 1981; Voldemort was set upon killing James and thus never gave him an opportunity to choose to save himself. Lily, on the other hand, was offered the chance to step aside because Voldemort had promised Severus Snape that he would not kill her unless she got in his way. Her conscious refusal to comply with Voldemort's demand is why unusually strong magical protection was conferred upon her only son.

Effects

"But I knew too where Voldemort was weak. And so I made my decision. You would be protected by an ancient magic of which he knows, which he despises, and which he has always, therefore, underestimated — to his cost. I am speaking, of course, of the fact that your mother died to save you. She gave you a lingering protection he never expected, a protection that flows in your veins to this day."

— The effects of sacrificial protection

Harry Potter allows Voldemort to hit him with the Killing Curse in order to protect the defenders of Hogwarts

Sacrificial protection can be conferred on a single beneficiary or on a group of them. In cases involving a single person, the protection prevents whoever murdered the person who sacrificed their life from physically touching the person saved without experiencing excruciating pain, and will cause a Killing Curse cast at the saved person by the murderer to rebound. In cases involving multiple beneficiaries, the extent of the protection is not known, but it seems that it is less than in single-beneficiary cases, so that spells cast by the murderer at those beneficiaries will simply wear off more quickly rather than be reflected back (although it is unknown how that would apply to the Killing Curse). However, the difference in the level of protection could also be attributed to whether or not the victim actually dies since, in the only known case in which sacrificial protection was conferred to a group of people, the intended victim survived.

Another defensive effect of sacrificial protection binds the beneficiary to life when his or her blood is transferred to another person (perhaps this only works when the beneficiary's blood is transferred to the murderer) as long as that person lives. If the blood is transferred to the murderer, then the murderer will be able to overcome some aspects of the protection. Evidence of this can be seen in the way that Lord Voldemort was able to touch Harry Potter and harm him after his rebirth and resurrection.

Bond of blood

"She may have taken you grudgingly, furiously, unwillingly, bitterly, yet still she took you, and in doing so, she sealed the charm I placed upon you. Your mother's sacrifice made the bond of blood the strongest shield I could give you."

— Explanation of the bond of blood

Albus Dumbledore leaves infant Harry Potter with a note on the doorstep of 4 Privet Drive so that the bond of blood he placed on Harry can be sealed

If the victim was related to the beneficiary, then a powerful charm known as the bond of blood can be cast upon the beneficiary to give them additional protection (although it is unknown how closely the two must be related for this charm to work). This charm prevents any harm from coming to the beneficiary from the murderer while they are in a blood-related relative's home.

However, in order for this charm's power to take effect, the living blood-relative must first take the saved person into their home willingly. Once activated, this bond of blood will prevent harm from coming to the beneficiary when they are in their relative's home but it will break automatically when the saved person moves out permanently or turns seventeen (the age of majority in the British wizarding world), whichever happens first.

Known occurrences

Harry Potter: "I was ready to die to stop you from hurting these people —"

Lord Voldemort: "But you did not!"

Harry Potter: "— I meant to, and that's what did it. I've done what my mother did. They're protected from you. Haven't you noticed how none of the spells you put on them aren't binding? You can't torture them. You can't touch them."

— Two mortal enemies face each other for the last time

Person(s) sacrificed	Person(s) protected	Date	Notes
Lily Potter	Harry Potter	31 October, 1981	Lily Potter sacrificed her life in order to protect her infant son, Harry from Lord Voldemort. This placed Harry under magical protection, so that when Voldemort cast the Killing Curse at Harry in turn, the spell backfired, leaving Harry unharmed (save for a lightning-shaped scar on his forehead) and Voldemort bodiless. Harry became the only known person to survive the Killing Curse because of the power of his mother's loving sacrifice. However, foreseeing Voldemort's inevitable return, Albus Dumbledore furthered Harry's protection by casting the above-mentioned charm on him and leaving him in the care of his only living relative, Petunia Dursley (Lily's older sister).
Harry Potter	Hogwarts' defenders	2 May,  1998	During the Battle of Hogwarts, Harry Potter willingly allowed himself to be hit with a Killing Curse cast by Lord Voldemort so that the piece of Voldemort's soul residing inside him would be destroyed and the Dark wizard could be defeated once and for all. This conferred a certain amount of protection on Harry's allies, making it so that spells Voldemort tried to place on them, including Silencing Charms and a Full Body-Bind Curse, quickly wore off.

Behind the scenes

• It would seem that the protection can take effect even if the opportunity for self-preservation is presented only by circumstance. In 1998, during the Battle of Hogwarts, Voldemort gave Harry one hour to surrender himself, vowing to hunt him down if he did not show up in that time. Nonetheless, although Voldemort was determined to kill Harry, Harry's sacrificial protection worked to save his friends, presumably because he willingly gave himself up despite having enough time to try to run away, whereas James Potter was only given a minute's notice of Voldemort's arrival. Also, he arrived to face Voldemort just after the required hour and by that time Voldemort thought he wasn't coming. In Harry Potter and the Philosopher’s Stone, Voldemort gave Harry the option to live in the face of death and Harry refused, fufilling the requirements to activate the enchantment.
• It's unknown if anyone employed by the murderer can harm a beneficiary. This is seemingly evidenced during the Battle of Hogwarts, where it's believed that Harry protected his friends from Voldemort, after which, not even any Death Eaters, much less Voldemort himself, were able to do any harm to the Hogwarts army.
• Because of Harry's sacrificial protection, the spells that Voldemort and his Death Eaters cast did not work properly. Voldemort's Silencing Charm did not keep the Hogwarts residents quiet for long, and Neville Longbottom was able to break the Full Body-Bind Curse Voldemort cast on him. Yet also in the final film, Voldemort casts the Stunning Spell on Neville out of anger after seeing Harry alive. This spell did not hold, either, as Neville woke up soon after. Furthermore, neither Voldemort or the Death Eaters were able to do any damage to the Hogwarts students, Professors, Hogsmeade villagers, Order of the Phoenix or other participants. Interestingly, Harry is also seen in the films as being able to deflect Killing Curses with a Shield Charm, although this may be to do with the allegiance of the Elder Wand rather than the sacrificial protection. This is the sole place in the final film where the blocking of a Killing Curse can be considered to be theoretically possible, as other blocks (such as by Bellatrix while duelling Molly Weasley) exist to elongate duels and increase drama, although it could be that Bellatrix merely used either a Stunning Spell or the Disarming Charm to prevent Molly's curses from hitting her.
• It is evidenced that people under sacrificial protection could be protected or protect themselves from the Killing Curse using Shield Charms, as Harry used them to protect his friends and allies from Voldemort's curses during the second part of the Battle of Hogwarts.
• It is seen during the Battle of Hogwarts that the spell only protects living people, as the Dark Wizards were still able to destroy areas of Hogwarts.
• Lord Voldemort's inability to understand the power of love made him severely underestimate and misunderstand the power of this protection. He believed that by taking Harry's blood for his regeneration, he would be able to bypass the shielding, and thought being able to touch Harry and affect him with spells, was evidence of such; contrarily, this strengthened the protection by preventing Voldemort from killing Harry, while Voldemort himself was still alive.
• Interestingly, the only two occurrences of the counter-charm have been through the Potter family in terms of Lily Potter (nee' Evans) and Harry Potter, mother and son. It is yet to be shown that this charm is demonstrated by someone outside the Potter family.
• Presumably, it is also possible to place sacrificial protection on one or more people by deliberately shielding the intended victim(s) from any curse or other Dark spell. If this is indeed the case, then it would be much more likely that the person who sacrificed him- or herself for others, actually still could survive it (like Harry did), as most curses are not deadly, at least not immediately.
• When Voldemort took Harry's blood to rebuild his body he unwittingly put a few drops of goodness back inside himself, that gave him one last chance to heal himself if he had repented.
• According to Rowling this kind of magic is very un-scientific and that there was no Elder Wand + Lily’s Blood = Assured Survival” formula but that it was ultimately the choices that Harry and Voldemort made.

Appearances

• Harry Potter and the Philosopher's Stone (First mentioned)
• Harry Potter and the Philosopher's Stone (film) (Appears in flashback(s))
• Harry Potter and the Chamber of Secrets (Mentioned only)
• Harry Potter and the Goblet of Fire (Mentioned only)
• Harry Potter and the Goblet of Fire (film) (Mentioned only)
• Harry Potter and the Order of the Phoenix (Mentioned only)
• Harry Potter and the Half-Blood Prince (film) (Mentioned only)
• Harry Potter and the Deathly Hallows (First appearance)
• Harry Potter and the Deathly Hallows: Part 2
• Harry Potter and the Deathly Hallows: Part 2 (video game)
• LEGO Harry Potter: Years 1-4
• LEGO Harry Potter: Years 5-7