Muggles' Guide to Harry Potter/Magic/Deathly Hallows

Overview
The Deathly Hallows are legendary magical artifacts of great power that purportedly allow the true owner of them to become "The Master Of Death".

Extended description
One of the three Hallows first appears in our story in Harry Potter and the Philosopher's Stone, though it is not identified as such for six years. A second one appears in Harry Potter and the Half-Blood Prince, though it also is not identified as being a Hallow for over a year. While the third Hallow appears throughout the series, no special note of it is made until it is identified as a Hallow in Harry Potter and the Deathly Hallows.

The Deathly Hallows are described to us initially in The Tale of the Three Brothers, one of the Wizarding fairy tales initially collected by Beedle the Bard. Hermione receives an early edition of this book in Albus Dumbledore's will, in which it appears Dumbledore has marked The Tale of the Three Brothers with what turns out to be the sign of the Deathly Hallows. Most believe the Tale of Three Brothers to be only a fairy tale, but there are a large number of wizards who believe the Deathly Hallows are actual artifacts.

According to the tale, Death himself gave the artifacts to the three brothers as reward for outwitting him. Dumbledore is less certain; he feels that the three brothers, the Peverells, were strong and dangerous magicians who created the artifacts themselves. We learn that one of the three brothers, Ignotus, is buried in Godric's Hollow, under a stone bearing the symbol of the Deathly Hallows; the other two, Antioch and Cadmus, we know little apart from their names.

The Deathly Hallows are:


 * 1) The Elder Wand - An undefeatable wand given to the "combative brother", it will defeat any wizard in a duel so long as it has accepted the wizard holding it as its master. It can also do magic at amazing levels outside of battle, for example fixing Harry's wand when even the wandmaker Mr. Ollivander states it can't be fixed. It was supposedly created when Death picked a branch from a nearby elder tree and charmed a wand out of it. The wandmaker Gregorovitch claimed to have found it and was supposedly studying its secrets so that he could replicate it; before he managed that, however, it was stolen from him by Gellert Grindelwald. Grindelwald used that as the core weapon in his war against the Wizarding government in Europe, eventually falling to Dumbledore in 1945. Dumbledore then carried the wand until it was, in turn, captured from him by Draco Malfoy. Draco, of course, does not know the history of the wand, and is unaware that it has shifted allegiance to him. Dumbledore is buried with his wand, and Voldemort eventually traces it to his tomb, and then steals it, thinking that this will make him the master of it. However, Harry has already won its ownership by disarming Malfoy; the wand may not be aware of this, until it is confronted with Malfoy's wand, the same wand that caused Dumbledore to give it up, in Harry's hand. In the end, the wand favours Harry in the final battle, and Harry returns it to Dumbledore's tomb. The author has indicated that the core of the Elder Wand is a hair from a Thestral, "a powerful and tricky substance that can be mastered only by a witch or wizard capable of facing death." This seems entirely appropriate given the association with death of the Elder Wand, and of the Thestral.
 * 2) The Resurrection Stone - This stone supposedly brings the dead back to life. According to the myth, it was created when Death charmed a stone from the river's edge for one of the Peverell Brothers. Throughout the seven books of the Harry Potter series, we are shown repeatedly that the dead can return in some form; there are the ghosts, of course, and the portraits, which share some characteristics of their originators: shape, memories, and apparently thought processes. There are the echoes of the people who Voldemort has killed, which are forced out of his wand by the Priori Incantatem effect in the graveyard; again sharing some of the characteristics of the people, although Dumbledore later says that they are not the people themselves. There is Voldemort himself, his soul anchored to the Earth by Horcruxes. And there is the Resurrection Stone, which does not actually reanimate people, but raises what might be called "shades", images of the summoned people with their characteristics, memory and appearance. This artifact was put into a ring which was passed down the generations of the Peverell Family, later becoming little more than a symbol of pure-blood pride. Voldemort, knowing only of its value as a relic of the now-gone Peverell family, and unaware of the connection with the Deathly Hallows, had turned it into a Horcrux and hidden it in the Gaunts' shack. Dumbledore, by the summer following Harry's fifth year, was hunting Horcruxes, having heard of the locket and the ring, and seen the destruction of the diary. He had traced the ring back to the Gaunts, and found it; though he had destroyed the Horcrux, in the process he had unwisely activated a curse in the ring itself, thus bringing an end, within the year, to his own life. Dumbledore passed the stone on to Harry by hiding it in the Golden Snitch which Harry had caught to win his first ever Quidditch match at Hogwarts.
 * 3) The Invisibility Cloak - According to the legend, this is not the sort of invisibility cloak that can be made by human hands, charmed with a Disillusionment charm or a Bedazzlement hex, or woven out of Demiguise hair, but rather is Death's own cloak, which unlike other cloaks, is immune to all charms, hexes, and even any form of physical damage which may occur to it. It is reputedly so powerful that it hides the wearer from even Death himself. Legend says that it will be passed down from father to son through the generations of the Peverell Family. Harry, Ron, and Hermione are stunned to realize that the cloak Harry is carrying while they are being told this is the only cloak they have ever seen that matches this description. Dumbledore later confirms this to Harry; the cloak had been passed down to the last descendants of Ignotus Peverell, born like Ignotus in Godric's Hollow: James Potter, and his son Harry. Only by two means has the disguise of the Invisibility Cloak been penetrated; the magical eye of Alastor Moody was able to see through it, and the Marauder's Map similarly would show the person under the cloak. It is uncertain whether the Cloak provides immunity to charms; it is certain that it is itself unable to be Summoned, as that was tried by Death Eaters at one point, so it is unlikely that it can be affected by any magical means. Unfortunately, while the cloak is immune to spells cast at it, it does not offer the same protection to those who use it. It is true that in the battle with the Death Eaters in Tottenham Court Road when a curse is thrown at Harry (who is under the cloak) he escapes untouched while a table behind him explodes, but it is uncertain whether the curse was properly aimed at Harry. However, when Harry hides in Draco's compartment on the Hogwarts Express, Harry is successfully petrified while wearing the invisibility cloak.

Analysis
As we can see from the above, while the Deathly Hallows are only named in the seventh book, they play a vital role in the entire series, and actually two of the three play a continuing role: the Elder Wand, which is Dumbledore's from when we first see him, and the Invisibility Cloak, which had been James' and was passed on to Harry. More than that, though: a large part of Dumbledore's youth had been involved in the search for the Hallows, and for the means of mastering Death.

Dumbledore had hoped, by having the Elder Wand placed with him in his tomb, that the power of the Wand would then be ended; the wand would transfer its allegiance to the latest person who had captured it, and as Snape had killed Dumbledore, it would be Snape to whom the wand owed its allegiance. Snape, possibly not believing in the Deathly Hallows and unaware that the wand was one of them, and having promised to have Dumbledore buried with his wand in his hands, would thus have eventually died without having forcibly lost the wand. Not being skilled in wand lore, however, Dumbledore was unaware that Draco's disarming him would cause the wand to transfer its allegiance. Harry had checked this point with Mr. Ollivander; it is the gaining control over the wand against the will of the current holder, not causing the current holder's death, that causes the transfer of allegiance. Voldemort had the same mistaken belief, which is what led to his killing Snape. Harry, believing that by capturing Draco's wand from him, and then by capturing the Elder Wand from Voldemort, he had transferred the Elder Wand's allegiance to him, had the wand re-interred with Dumbledore's body. When Harry dies, if the wand has remained in Dumbledore's tomb, it will be impossible for anyone to gain its power, as Harry will not be there to try to prevent it.

While it is likely that Dumbledore would have been able to use the Resurrection Stone to bring his loved ones back, he was initially misled by the Horcrux in the ring, and then later came to believe that there would be no point. The brother who had received the Stone in the legend had caused his sweetheart to be resurrected, but had found that the resulting simulacrum was worse than her absence in death had been, and eventually he had killed himself to be properly reunited with her. Dumbledore rightly decides that he is likely to suffer the same sadness; the re-animated Percival, Kendra, and Ariana will not bring him joy at their return, but only sadness at their incompleteness. Harry, in his turn, though, uses the Stone not to recover those he has lost, but to seek their support in what he has to do. It is not the people themselves he wants, but their spiritual support, which as spirits they are uniquely able to provide. Having received that support from them, Harry deliberately drops the stone in its ring, and chooses to not search for it.

The Cloak, of course, is the one that Harry is carrying. On the night that James had been killed, Dumbledore had the cloak and was examining it; by that time, he had given up seeking the Hallows, but here was his chance to actually hold two of the three at one time. In the end, Dumbledore had passed it to Harry, as James would have wished; Harry chooses to pass on to his own descendants, as it was passed on to him. Dumbledore seems to think this is only right and proper. The fact that the cloak is out of the ordinary is a new idea to Harry and Hermione, as it is to us, the readers, when the story of the Deathly Hallows is presented to Harry; Harry's Cloak, exceptional as it may be, is the only one we've ever had the chance to examine. Ron may understand that it is out of the ordinary, but Ron is, relatively speaking, immature; he may not make the connection until Xeno Lovegood spells it out for them.

It may be worth mentioning that Voldemort had likely never heard the tale of the Three Brothers. Fairy stories are typically told to the young, of course, and at the age where he would be expected to hear these stories, he would have been in the Muggle orphanage. As a result, he likely heard of Cinderella, which wizards have never heard of; but the tales of Beedle the Bard would be a closed book, being too young for him and therefore something in which he was not interested when he finally entered the Wizarding world. This could explain why he was so interested in Horcruxes, and paid no attention to Hallows; he was unaware of the existence of the Hallows, to the point that he actually changed one of them into a Horcrux. It is true that he seeks the Elder Wand; however, Xeno Lovegood tells us that the Deathstick, as it is also called, has left a broad and bloody trail through history, and so for Voldemort it may have an existence totally separate from the other two Hallows, which have been less prominent in Wizarding history.

One of the things that is repeated a number of times is the idea that the holder of all three Hallows will be truly the Master of Death. The naïve wizard will think that this means that he will have power over Death, able to kill others and resurrect them with impunity, and hide from death himself. It is apparent from looking at the effects that the Hallows actually have that this is not what happens. While the holder of the wand cannot be bested in battle, still the wand may be removed from him by force, and he himself could be killed by non-magical means. The stone will not truly resurrect, but will only provide the sort of pale imitation of life that ghosts have. And one can hide under the cloak for a limited time only. The only way to achieve mastery over death is to understand it and be prepared for it. Dumbledore has said something about this as well: as early as the first book, Dumbledore said "To the well organized mind, death is but the next great adventure." Death can be postponed, as demonstrated by Nicholas Flamel, but it cannot be avoided; to gain power over death, you must gain understanding of it and lose fear of it.

One thing that is brought out is that the Hallows do prove something of a litmus test for the personality of the wizard. When Harry, Ron, and Hermione are discussing them, they each immediately choose which of the three is the most valuable. Hermione chooses the cloak, Ron the wand, and Harry the stone. We see immediately that Ron, in thinking of an undefeatable wand, is seeing himself as the head of a gang of followers; Harry is mourning his losses still, though perhaps more wistfully than actively; and Hermione, aware of the value of the cloak that they actually have, is thinking of how much they have been able to do while concealed by it. The young Dumbledore and Grindelwald similarly select the wand and the stone, for similar reasons.