Since Tolkein’s Mount Doom, volcanoes and lava have been a staple of fantasy storytelling. D&D is no different!
Whether you’re fighting a dragon at the precipice of a volcano, escaping a castle as it collapses spectacularly into a bubbling sea of lava, or even adventuring in the Elemental Plane of Fire, lava comes up a lot in D&D games.
D&D’s official rules for lava are sparse and leave a great deal to DM discretion. That said, this guide should help you to run lava in your game.
This is what you’re probably here for – how much damage does lava do?
Well, conveniently, page 249 of the Dungeon Master’s Guide uses lava damage as an example when providing guidelines for DMs to improvise damage.
Wading through a lava stream causes you to take 10d10 damage. Being fully submerged in lava causes you to take 18d10 damage.
There are also some edge cases where the DMG doesn’t provide direct examples. How much damage do you take if you’re hit by a globule of lava? What about if you touch lava with your hand?
The DMG leaves these up to your discretion, but we’ll try to provide some guidance on how to rule in these cases.
In the real world, lava is so dangerous that geologists often need to wear special fire-proximity suits to withstand being close to large lava flows.
If you want to make lava in your D&D world feel similarly dangerous, large flows could deal a small amount of fire damage (1d6) each turn to any creature within 5 feet of it.
Standing similarly close to a lava lake might deal significantly more.
While it’s true that any real human would die instantly if submerged in lava, D&D is a fantastical game and high-level D&D player characters are more comparable to superheroes than they are to any real person.
It’s not unreasonable, within that framework, that high-level PCs could survive things that would mean certain death for any real person.
Avoiding Damage From lava
Generally, the way you avoid taking damage from lava is by avoiding touching it at all. For DMs, that means you should implement dexterity saves for players to avoid falling into lava in the first place.
There are also spells that may come in handy here. For example, Fire Shield can be used to gain temporary resistance to fire damage. Other spells, such as Levitate, can also help in avoiding falling into lava.
Realistic Lava Density
In reality, lava is much denser than water. Even if it were possible to withstand its immense heat, swimming in lava would still be impossible, and falling into lava would be much more like falling onto lava.
Trying to simulate this in your D&D games is less intuitive but may be worthwhile if you’re running a lava-heavy campaign – for example, a campaign set in the Elemental Plane of Fire or Avernus.
If you’re running lava in this way, then damage from immersion in lava would, in addition to fire damage, deal large amounts of bludgeoning damage.
A creature becoming submerged in lava would be crushed as it was pressed into a substance with the density of rock.
This bludgeoning damage would also continue afterward as the creature was crushed by lava pressing into it from all sides.
Lava’s density is also important if your campaign features vehicles that move across lava.
Rather than boat-like vehicles that move through lava flows while magically withstanding the heat, you may prefer to implement vehicles that travel on top of the lava.
This could take the form of huge walker-style vehicles with large fireproof snowshoes or fireproof sleds. Even wheeled vehicles aren’t out of the question here.
Lava in Motion
It might often be more convenient for lava to be static in your game. In reality though, lava flows and lakes are the venting points for unimaginable geological pressure.
Large lava lakes in particular are places of constant violent motion. Getting close to lava lakes involves a high risk of being hit by chunks of molten rock, but even the ground beneath your feet is subject to change as it melts away.
As a DM, it’s important to run this in a way that’s fun. If the ground collapses beneath your players’ feet with no warning or foreshadowing, that won’t be an enjoyable experience.
That said, if players see lava impacting the landscape from a distance first, then they’ll expect these geological forces to impact them in the future.
If your players see a high-CR creature die after becoming enveloped in lava, that tells them that lava presents a real and terrifying danger to them.
You can also use descriptive clues that such events are imminent.
For example, if a crust of solidified rock is overturned and melted back into the roiling lava below, that’s a hint that there are geological forces in motion that the players need to worry about.
If you describe how the ground is starting to feel warm, your players will usually be able to infer what’s about to happen.
Creatures Found Near Lava
Many of D&D’s creatures have an affinity for lava and may make great enemies or even allies in lava-heavy play settings.
Fire giants, salamanders, azers, and magmen are great staples of lava-based encounters.
Magmen in particular, with their ability to explode on death, can make great “trick monsters” that thematically play into the explosiveness and destructiveness of lava and volcanoes.
Gold, brass, or red dragons might also feel at home near volcanoes.
As with all environmental hazards, enemies that push the PCs around can make for some tense moments when lava is present.
A minotaur might not seem like an obvious choice for an encounter near a lava lake, but its Charge attack has a 10-foot knockback effect that introduces the possibility (however small) of instant death to the minds of your players.
Lava-Related Player Characters
There are also options for lava-linked player characters. Fire genasi are an obvious choice as humanoids touched by the Plane of Fire.
These characters often glow with internal heat, and their fire resistance will come in handy in lava-heavy environments.
Earth genasi are also a great lava-focused option. Many earth genasi have “fissures in their flesh, from which faint light shines” (page 9 of Elemental Evil – Player’s Companion), and, depending on your DM, earth genasis’ Earth Walk ability may provide benefits in magma-heavy settings.
“Earth Walk. You can move across difficult terrain made of earth or stone without expending extra movement.”
Elemental Evil – Player’s Companion, page 9.