I remember coming across the description of a lich in the Advanced Dungeons and Dragons Monster Manual when I was a kid.
I didn’t get what a lich was supposed to be. The picture wasn’t that descriptive, and it basically read like a guy who studied a lot. As far as I could tell, he got so obsessed in magical study that he didn’t realize when he died, and became undead to continue pursuing magical knowledge. Lame, I thought. Especially with a monster name as silly as “lich”.
The Lich is much more than that. The Pathfinder Reference Document (spiritual successor of Dungeons and Dragons) describes it better. This is a person who pursues evil magic for the express purpose of power and becoming immortal. He does this by using necromantic arts to cut off and hide parts of his soul in a thing called a phylactery. From the PRD (as previously linked): “The process involves the extraction of the spellcaster’s life-force and its imprisonment in a specially prepared phylactery—the spellcaster gives up life, but in trapping life he also traps his death, and as long as his phylactery remains intact he can continue on in his research and work without fear of the passage of time.”
To kill a lich, one must first kill the phylactery.
The first time I encountered this idea was in a series of children’s books based off of Welsh mythology (the Mabinogion) called the Chronicles of Prydain. Unfortunately, it’s been so long that I can’t remember the details, or even in which book of the series it occurred, but there was a sorceress that they couldn’t kill without finding her phylactery and destroying it (and with it, her soul).
While there are similarities with the character of Sauron in the Lord of the Rings (can’t kill him until you kill the One Ring), he’s not quite a lich. The Ring acts as a phylactery, because as long as the Ring exists, Sauron’s spirit will always endure to return. However, one of the key ideas of being a lich is that the lich was once a mortal man or woman. The lich forsake who they were to rise to power. Sauron was always an immortal spirit.
In World of Warcarft (WoW), we see another use of the term lich: The Lich King. While WoW has some lich characters with phylacteries, Arthas the Lich King is a horrible example of a lich. He’s a king who takes an evil sword, becomes corrupted, and undead. As far as I’ve read, he has nothing that acts as a phylactery, and he’s not a spell caster. He has powers granted by his undead status (really, he’s more of a death-knight on steroids), but he’s no wizard. That’s one of the other characteristics of a lich: being a wizard. So, my working definition:
A lich is an evil wizard who uses necromancy to cut out and hide fragments of his soul in objects called phylacteries in order to achieve immortality through undeath.
So, in recent literature, I realize that the Harry Potter series is the clearest depiction of a story centered around a lich. Voldemort is not just an evil wizard. He’s bent on immortality (as he tells Snape when he kills him). He has not just 1 phylactery, but 7, which they call horcruxes. With each horcrux made, he loses his humanity. While not explicitly undead, he’s starting to look that way. He was killed, but because of the horcruxes, his spirit endured and returned. J.K. Rowling doesn’t use the word lich, or phylactery. From what I can ascertain, I’m not sure she deliberately set out to make a lich story. However, I can’t think of another tale that so clearly depicts the concept.