Phylactery

A phylactery (or jar ) was the name given to the repository used to store the life force of a lich. A cleric or mage had to create such a phylactery in order to become a lich,      and it was necessary for the lich to maintain its undead state and escape being destroyed. Phylacteries were also employed by dracoliches and demiliches. Every phylactery was unique, in nature, defense, and means of destruction.

Creation
Making a phylactery was a highly expensive and taxing effort, requiring a high degree of spellcasting ability and total materials valued at 100,000 to 120,000 gp. While any object could be chosen to be the lich's jar or phylactery, it must be made of a solid material (and not wood) and be of high-quality craftsmanship. It could be non-magical or already be a magical item. It must cost no less than 2000 gp or much more, at least several thousands of gold pieces according to the maker's spellcasting power.

First, a prospective lich must cast the spell enchant an item on the object. If this worked, this was followed by trap the soul. If it was successfully made receptive to a soul, the would-be lich cast magic jar on the object, thereby making it the phylactery. This had the effect of binding the caster's soul to the mortal realm, stopping it from going onto the Outer Planes after death. Permanency and reincarnation could also be required.

Then the lich's soul entered the jar for the first time, but this exhausting process caused a loss of life-force and might, as well as erasure of their most powered prepared spells. Once their soul and vitality were successfully stored in the jar, they could leave and rest for at least a few days to recover.

Creation of the phylactery took a tenday to achieve. Only after it was complete could the lich commence the deadly ritual to fully achieve lichdom. A lich who survived the destruction of their phylactery could create a replacement at half cost.

Powers
Even before becoming fully a lich, the jar was of benefit to its still-living creator. If they died by any cause, their soul returned to the jar, regardless of how far away or what obstacles were before it, but it lost life-force and power once again. They could then reemerge and possess any dead body in the vicinity, whether their own, another's, an animal's, or an outsider's, becoming something like a wight.

If a lich's physical body was destroyed, it could regenerate itself where its phylactery was located within a tenday, with a new body appearing adjacent to it. However, if the phylactery itself was destroyed, then the lich could not regenerate and would remain destroyed.

To sustain the power of the phylactery and their undead existence, a lich needed to fuel it with the souls of others. They used the imprisonment spell to trap the soul of a victim within the phylactery; it would be held there for a full day before being consumed entirely unless freed with a dispel magic. A lich that did not trap souls in the phylactery regularly risked decaying physically and ultimately becoming a demilich.

Therefore, to guarantee destruction of a lich, it was necessary to destroy both body and phylactery. However, destroying the phylactery was difficult and usually a special item, weapon, or ritual was needed.

Defenses
For this reason, liches sought to guard their phylacteries thoroughly against any attack and to place them in secure and secret locations. Typically, they chose hidden and well-defended vaults, even on other planes.

However, as a lich needed to be able to come and go and have spare bodies to inhabit, the jar needed to be in some accessible location; one that was too well-hidden might see them trapped. A lich's jar could not be found by locate an object, unless enacted by a god and even then the range was limited to the same plane and a distance of.

The spell of epic magic called Aumvor's fragmented phylactery let a caster have multiple phylacteries, either by splitting an existing phylactery into multiple pieces or turning several other items into phylacteries, though the number created in one casting was limited. The lich's enemies were forced to destroy all the phylacteries, so permanently destroying the lich became almost impossible.

A lich whose phylactery was seized by another might be obliged to serve its holder, as happened to Rhangaun of the Twisted Rune. Alasklerbanbastos, the Great Bone Wyrm of Threskel, kept the phylacteries of minion dracoliches "in trust".

It was claimed that the demon lord Orcus, the patron of liches, could immediately obliterate the phylactery of any lich he was displeased with.

Description
A common form of phylactery was a sealed metal box, from the size of a fist to wide. Inside of this were strips of parchment bearing magical phrases and sigils written in silver or the would-be lich's blood; these were the spells of naming and binding, dark magic, and immortality that maintained the lich's existence. However, a phylactery could be any number of things, such as a ring or amulet, provided it had an interior space in which such writings could be placed. Other possibilities were a gem or even a totem doll. Jewels, magical items, stones, bones, books, swords, and even mythals were all known.

Notable Phylacteries
The Netherese lich Aumvor the Undying made his phylactery the rune-inscribed skeleton of his former rival Dethed, an apprentice of Ioulaum. He used his fragmented phylactery spell on it so often that by 1374 DR all 206 bones of the skeleton were his phylacteries. Most of them were shrouded from divination magic and stashed in secret places all around the Endless Caverns, with a few in more distant places.

The Lichdrow Dyrr kept his phylactery, a beljuril, within a guardian golem shaped like a spider in the temple to Lolth in the estate of House Agrach Dyrr. Dyrr placed a master ward, which activated all wards in the compound and destroyed the house in the event that the phylactery was destroyed.

Wulgreth used the artifact known as the Karsestone as his phylactery. It was last known to be in the hands of no less than the goddess of darkness Shar.

Of dracoliches, Iltharagh, "Golden Night", made his phylactery a large golden topaz sphere in a platinum stand, kept within his treasure hoard. Kazmil-urshula-kelloakizilian's was concealed in a book of creation, a relic of the Witch-King Zhengyi. Dretchroyaster's phylactery was the sword Dragonslair and Greshrukk's was to be a glassteeled ruby in the pommel of a sword named Dragonstooth, before his transformation was interrupted and failed. Reveilaein the half-dragon dracolich made his phylactery the headband of intellect he wore.

Raerlin seems to have made his phylactery a book that came into Elminster's possession by 1355 DR.

In 1373 DR, Sammaster completed his transformation of the Dracorage mythal, binding his phylactery to its capstone chamber. This precipitated a Rage of Dragons independent of the King-Killer Star.

In 1484 DR, the Harpells gave Catti-brie a blood-red sapphire ring to serve as a phylactery to trap the soul of the vampire Thibbledorf Pwent. After she instead used it to trap the lich Ebonsoul, she was forced to capture Pwent in Wulfgar's horn of summoning.

Background
Phylactery, from Ancient Greek (via Latin) for "protectant", is a term for a charm or amulet, a Christian reliquary, or a translation of the Jewish tefillah. It is also the term for "speech scrolls" in Medieval art.

In D&D, a phylactery was first mentioned in relation to a lich in the 1-edition Monster Manual (1977), but from this it is not clear what the phylactery is or why it is necessary. In 1979, "Blueprint For A Lich" in Dragon #26 first detailed the process of achieving lichdom, but referred instead to a "jar"; it's not clear if this is meant to be the same as the phylactery or not. This jar concept takes after numerous legends and stories of mages and villains who store their souls, hearts, life, or death in some object in order to cheat death. According to research by Buzz, here, the Endless Quest gamebook Lair of the Lich (1985) was the first to link the lich's phylactery to the soul-jar concept, perhaps based on a misunderstanding of what a phylactery is. Since then, the term "phylactery" has become generally associated with liches and soul jars, both within D&D and across fantasy fiction. It wasn't until the 3-edition Monster Manual (2000) that a generic lich's phylactery was described in terms inspired by the various real-world historical phylacteries.

In D&D, the term "phylactery" is also used for various magical items worn on the head associated with morale and alignment, while a mundane phylactery for priests has also been present. These more closely take after the original real-world phylacteries.