Mistilteinn: The Draugr's Blade
A deadly column about folklore and tabletop RPGs
Long before modern fantasy novels and D&D, people were already imagining magic swords in hidden tombs, and the Norse were no exception. So gather round and let me tell you the tale of Mistilteinn, the magic sword Hromund Gripsson stole from an undead king.
Mistilteinn (“Mistletoe”) is a sword from the Icelandic Hrómundar saga Gripssonar (“Saga of Hromund Gripsson”). It originally belonged to the undead witch-king Thráin, before he was slain by our titular hero Hromund Gripsson. The only man brave enough to enter the barrow where the undead Thráin had sequestered himself, Hromund wrestles the king into submission, burns his body, and steals his treasure, including Mistilteinn.
The story describes Mistilteinn as an enchanted sword, one whose blade never dulls. It’s also instrumental in helping Hromund win his many future battles across the saga, giving it the implicit quality of not being interchangeable with just any other weapon.
Thráin (a transliteration of the Icelandic name ‘Þráinn’) is a powerful sorcerer and the original owner of Mistilteinn. In his hands, Mistilteinn was used to kill four hundred and twenty men, including Sæmingr, the legendary first King of Norway.
“In previous days Thrain had been king over Gaul, and he had accomplished everything by sorcery. He did much evil, until he was so old that he no longer wanted to know adversity any longer, so he went alive into the barrow and took much wealth with him.”
Rather than die, Thráin became a draugr—an undead revenant of Scandinavian literature and folklore. Draugr are corporeal ghosts, typically found haunting their gravesites and barrows (from the 1800s onwards, they are sometimes referred to as barrow-wights). The true nature of these creatures is readily apparent, appearing death-blue, corpse-pale, or skeletal, and frequently accompanied by a reek of decay. Draugr often have supernatural powers too, such as shape-shifting and controlling weather, and are always malevolent, motivated in their undeath by greed and bloodlust. Some draugr are immune to weapons and must be wrestled back into their grave to be defeated, while others appear nominally vulnerable—but can only truly be killed if their head is removed and their body burned.
Mistletoe has a special place in European folklore, especially pre-Christian folklore, where it represents romance, (male) fertility, and vitality. According to Pliny the Elder’s Natural History, the Celtic Druids performed a ritual where mistletoe and animal sacrifice were used to create an elixir to cure infertility and the effects of poison. Looking to the Romans, the Golden Bough the hero Aeneas needs to take with him to the underworld as a gift in the Aeneid is often believed to be mistletoe.
Famously, mistletoe is the one object the Norse goddess Frigg deems too harmless and/or young to swear an oath to not harm her son Baldr. Of course, Loki then fashions a spear from mistletoe and tricks Baldr’s blind brother Höðr into accidentally killing him with it. But what’cha gonna do? Loki’s gonna Loki.
Saxo Grammaticus’ 12th-century work Gesta Danorum (“Deeds of the Danes”) reframes the story as having Mistletoe be the name of a sword Höðr purposefully uses to kill Baldr. While there’s nothing to say that these two Mistilteinns are the same sword, who’s to say they aren’t?
While the magical properties of Mistilteinn are mostly unelaborated upon, we can take these ideas to give the weapon one of two specific powers. The first is restorative, where the sword can be used to cure poisons and break curses. The second is destructive, where it has the ability to cut through any kind of resistance, immunity, or magical defence.
Using Mistilteinn in Your Game
The great thing about magic swords is that they’re increadibly easy to drop into any game—especially if you don’t take what they represent and can do too literally.
Sometimes you don’t need a complicated reason to go into a barrow and try and steal a dead guy’s magic sword (Hromund Gripsson definitely didn’t). Thráin, his sword, and his buried riches can be easily dropped into your campaign as a one-off adventure or a location to discover during a hex crawl.
Mistilteinn the Key
If we take Mistilteinn as having the power to cut through any defence, it’s easy to imagine why your PCs might go on an adventure to obtain it. If a godlike being can’t be harmed by any normal magic or weapon, then only a quest to find and obtain the enchanted sword can prepare the party for defeating them. Alternatively, perhaps some location is impenetrable due to its magical wards or defences—Mistilteinn could be the key to cutting a path through those too.
This idea can be extended beyond just Mistilteinn as a sword too. Perhaps in a cyberpunk setting, Mistilteinn is a powerful program that can break through any firewall. In an espionage game, it could be the codename for a dossier that can bring down even the most powerful individuals or companies. You can even still keep it a sword in a modern or sci-fi setting, by having it be a prototype developed with the ability to cut cleanly through any material. That’s still plenty worth fighting over.
Mistilteinn the Antidote
The other famous use of mistletoe in folklore is as an antidote to poison and evil. Mistilteinn can then be sought out not for its destructive potential but for its ability to cleanse and sever curses. If some powerful poison with no known cure infects an important NPC—or even a PC!—the party can journey to uncover the lost sword and save their friend. Given it’s obvious use and power as a weapon, whoever currently owns it is likely to be unwilling to part with it too easily.
Thráin the Warlord
By the time we meet him, Thráin has already grown weary of his kingdom and retired with Mistilteinn to his barrow. The Hrómundar posits him as the former King of Valland, a stand-in for either Gaul specifically or the part of Europe inhabited by Celtic and Romance peoples more generally. But just because our Thráin retired doesn’t mean yours has to. Perhaps he withered and died, but kept on as a draugr king, relentlessly and unerringly pursuing conquest. Alternatively, perhaps he did retire to a barrow, but has grown bored of that too. Now, in your urban fantasy game, he’s preparing to use his sorcery to raise an army and resume his quest for dominion over Europe (and perhaps even the world). All he has to do first is hunt down the sword Hromund stole from him all those centuries ago—perhaps by taking it from one the PCs who acquired it in a previous adventure?
Mistilteinn (Old-School & 5e)
Mistilteinn is an enchanted +2 sword and can bypass all damage immunities. It cannot be dulled and, on a natural 20 on an attack, severs one of the target’s extremities (determine randomly).
▶ Weapon (longsword), legendary (requires attunement).
▶ This weapon ignores resistances to damage it inflicts, and treats immunity to damage it inflicts as resistance instead.
▶ When you roll a 20 on an attack roll with this weapon, you sever one of the target’s extremities (if possible; determine randomly). If this does not instantly kill the target, the creature takes an extra 4d8 slashing damage.
Thráin Statistics (Old-School)
Armor Class: 0 
Hit Dice: 10*** (45 hp)
Attacks: 1 x Mistilteinn (2d8+2) or 2 x claws (1d8) or 1 x magic
THAC0: 11 [+8]
Move: 90’ (30’)
Save As: Fighter 10
▶ Aura of Fear: All who see Thráin must save versus spells or flee for 2d6 turns. Characters above 4th level are immune.
▶ Stench of Death: The first time a creature comes within a 20’ radius, it must save versus poison or die.
▶ Arcane spells: Cast spells as a 10th level magic-user.
▶ Undead: Make no noise, until they attack. Immune to effects that affect living creatures (e.g. poison). Immune to mind-affecting or mind-reading spells (e.g. charm, hold, sleep).
▶ Draugr Immunities: Can only be harmed by magical attacks. Immune to electrical and cold attacks. +4 bonus to all saving throws against magic.
▶ Deathless: If reduced to 0 hp, Thráin will appear dead for 2d6 rounds, after which he will regenerate back to 45 hp. He can only be truly killed if his head is severed and his body burned before this happens.
Thráin has great but not superhuman strength. It is possible, if extremely difficult, to wrestle him into submission.
And that’s it for Mistilteinn and Thráin!
This article’s publication marks a full month now since Mythoi launched and we’re only just getting started. Thanks to everyone who’s jumped on board so early; if you’ve enjoyed what you’ve read so far, please feel free to tell a friend who you think will like it! Every new reader makes it easier for me to spend time writing this column week after week, and it’s been a blast so far. Either way, stay tuned for many more folktales and myths to come!
Penny for your thoughts: What’s your experience with raiding barrows? What’s the worst undead monster you, or your players, have disturbed in one of them?
~ A.C. Luke
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“Hrómund Gripsson's Saga”. Translated by Gavin Chappell. Retrieved 12 July 2022.
“Hrómund Gripsson's Saga”. Translated by Gavin Chappell. Retrieved 12 July 2022.
Williams, Howard. 2006. Death and Memory in Early Medieval Britain. Cambridge University Press: Cambridge.
Curran, Bob. 2005. Vampires: A Field Guide to the Creatures that Stalk the Night. Career Press: Franklin Lakes.
Pliny the Elder. Natural History XVI, 95.
“The History of Mistletoe”. The Telegraph. Retrieved 12 July 2022.
Snorri Sturluson. Prose Edda Gylfaginning, 49.
Saxo Grammaticus. The Danish History Introduction.
I really enjoyed this post! it was inspiring and informative. Thank you for sharing!