September 23, 2023

5 Mythical Substances to Spice Up Your Setting

Who doesn’t love a good made up substance? If you’re playing Dungeons and Dragons or a Lord of the Rings game, you get access to mithril. There’s a reason orcs fight over shiny shirts. If you’re playing the Star Trek roleplaying game, you gotta worry about loading up on dilithium. Let’s be honest, we’ve all come to the conclusion getting an adamantium skeleton put in you would be well-worth the trouble.

If you’re looking for some more made up materials to add extra flavor to your game, we’ve got five of the best here for you.

Red Mercury

In the late 80s, rumors began to emerge about a highly sought after material known as red mercury. It was purportedly a Soviet scientific breakthrough and key to cutting edge nuclear weapons and stealth technology. Most worryingly, sources claimed that red mercury, with its awesome destructive potential, was circulating around the black market. All any tinpot dictator or terrorist organization had to do to leapfrog into a nuclear powerhouse status was to get their hands on some of this compound.

Luckily for everyone it doesn’t actually exist, but because of its reputation, con artists were said to have commanded between $100,000 to $300,000 per kilogram of red mercury. In spite of never actually materializing, the legend has persisted. Several men were arrested in Britain in 2004 on suspicion of trying to buy some.

The great thing about red mercury is that it sounds like serious stuff that can basically do anything. This would slot in perfectly to a near future science fiction or cyberpunk game. Since it can be used for nuclear reactions, maybe your players need to secure some to make a mini-reactor capable of powering an experimental AI, or to keep it out of the hands of an apocalyptic cult seeking to craft a neutron bomb. Maybe it’s as simple and self-serving as a cat burglar in your party wants some to craft themselves a fancy new stealth suit.


In the Odyssey, Hermes gives Odysseus this herb to protect him from the minor goddess Circe’s powerful enchantments. Homer describes it thusly: “The root was black, while the flower was as white as milk; the gods call it Moly, Dangerous for a mortal man to pluck from the soil, but not for the deathless gods.” It’s not clear why it’s dangerous for humans to harvest, but not to handle. Historians argue about what potential real world plant was being described here, but this article is about mythical substances, so for our purposes we’re going to assume it’s mythical and magical.

What can we do with a plant that’s extremely difficult to gather, but protects against magic? Maybe it’s the last thing your party needs before the big assault on a lich’s lair. The lich could be holed up in an ancient catacomb pulsing with necrotic energy that causes any living thing to wither when exposed to it. The players have to find a creature willing and able to collect the Moly root. This means potentially trying to make contact with angels, demons, or some other powerful entity. Who knows what demands the creature they contact might make?

Xirang, Swelling Earth

Like many others, Chinese mythology contains a great flood story. According to the legend, a demi-god named Gun was tasked with solving a generational flood enveloping most of the land. To accomplish this task, he employs a material called xirang, which translates to something like ‘swelling earth.’ Gun fails in this task, but his son eventually uses this magical substance to plug the myriad springs causing the deluge. The soil is said to be able to expand continuously.

You could just run with this at face value and have your players build a system of dykes to save a city, but I think that’s a little too on the nose. To get the most bang for your buck, I suggest using this as a reward in a nautical campaign. Perhaps a single bag of xirang can be emptied to any spot on the high seas and coalesce into a small island within hours. This would allow your players instant access to the safe haven and hidoute of their dreams.

Mead of Poetry

So, the mead of poetry has some indelicate origins. Two groups of warring norse gods sealed a treaty by spitting into a vat. This spawned the demi-god Kvasir, who spent his time spreading knowledge around the world. A couple of dwarves teamed up to kill and drain Kvasir of his blood. They then mixed his blood with honey to brew the mead of poetry. I don’t 100% follow the line of decision making that led to its creation, but we’re left with a magical drink that instantly turns whoever drinks it into a master scholar, poet, or historian. The draught was apparently so potent that Odin himself conspired to steal some.

The mead of poetry could fit any number of roles in a game. If you’re playing D&D and have a character who wants to cross-class into bard, perhaps you could have a questline that requires them to obtain some of the precious beverage. Maybe a sphinx has promised a treasure hoard to any who can answer his unsolvable riddle. A player just needs a couple sips to gain that divine inspiration to outsmart the mythical beast. Or it could be as simple as the McGuffin a down on his luck composer hires the group to secure for him.


There was a belief in ancient times that since some toads produce venom, they must contain the antidote somewhere inside themselves as well. Enter the toadstone. These small, smooth stones were believed to ward off poisons and ensure overall health and wellness. Jewelry set with toadstone was highly sought after up until the mid 1700s not only for its beauty but also for its healing properties. I don’t know why this belief persisted as long as it did, seeing as no toadstone was ever discovered anywhere inside a toad. Rather the examples of toadstones we have today have turned out to be fossilized teeth of a prehistoric fish called lepidotes.

If they were real, the reason you’d want a toadstone is pretty obvious. Who wouldn’t want to be protected from poison and disease just by wearing a toadstone amulet. I think the fun really comes in when you consider actually trying to procure a toadstone. It could be a fun side quest to have your players venture deep into a haunted swamp to capture the specific magical breed of frog that houses the mythical stone. However, I think it would be more fun to tie the toadstone to the criminally underutilized froghemoth. If you’ve never heard of it, the froghemoth is an elephant sized amphibian known for swallowing its victims whole. Rather than kill the majestic beast, have the frogstone reside in the belly of the monster requiring a player to be deliberately devoured, snatch the stone, and then find a way out.