Magma Mephit 5e: Heat Metal, Lava Breath and a Fiery Death

A magma mephit is a CR 1/2 Small elemental with AC 11, 22 hit points in the 2014 rules (18 in 2024), a 30-foot fly speed, immunity to fire and poison, and vulnerability to cold. Its breath and its death burst both deal 7 (2d6) fire against a DC 11 Dexterity save, the highest DC of the four SRD mephits. The 2014 version also casts Heat Metal once a day, which can cook a fighter in plate armor for a minute. The 2024 magma mephit loses Heat Metal and False Appearance, and gains a slightly hotter claw.

Table of Contents

• •Magma Mephit Stat Block (2014)
• •The Magma Mephit in the 2024 Rules
• •How Magma Mephits Fight
• •How Many Magma Mephits for Your Party?
• •How Players Beat Magma Mephits
• •Magma Mephit Encounter Ideas
• •Frequently Asked Questions

Magma Mephit Stat Block (2014)

Its innate Heat Metal has a fixed save DC of 10 and needs no material component. The spell targets a manufactured metal object the caster can see within 60 feet: a sword, a shield, a chain shirt, a suit of plate. Anyone touching it takes 2d8 fire (9 average) when the spell is cast, and the caster can repeat the damage as a bonus action on each of its later turns while it concentrates, for up to a minute.

Its False Appearance makes it look like an ordinary mound of magma while it stays still.

The Magma Mephit in the 2024 Rules

Without Heat Metal, the 2024 magma mephit is a plain fire skirmisher. Its CR stays 1/2 but it is easier at the table than the 2014 one.

How Magma Mephits Fight

Heat the heaviest armor (2014). Heat Metal's Constitution save only decides whether the target drops the object. Nobody drops plate armor mid-fight, so the target has Disadvantage on attack rolls and ability checks until the start of the mephit's next turn every time it takes the damage. The damage on casting plus three bonus-action repeats averages 36 fire, more than a level 3 fighter's hit points. While it concentrates, the mephit still has its action for the breath or claws.

Keep the heat away from the fighter. The mephit flies 30 feet and has a Stealth bonus of +3. A mephit with Heat Metal running should stay airborne and out of melee, because each hit forces a DC 10 Constitution save (it has +1) to keep concentrating.

Breathe, then wait. Against a character with Dex +1, the DC 11 Fire Breath lands full damage when the character rolls 9 or lower, 45% of the time. Two characters in the 15-foot cone take about 10 damage between them. The breath comes back on a 6 at the start of its turn, so expect it once or twice per fight.

Die next to someone. The Death Burst is the same 7 fire at DC 11. A wounded magma mephit should dive into the middle of the party, so whoever kills it in melee pays for it.

How Many Magma Mephits for Your Party?

A magma mephit is worth 100 XP. Our encounter calculator shows the 2014 Dungeon Master's Guide guidelines too.

In a 2014 game, count each magma mephit's Heat Metal as the threat. Two mephits heating two armored characters at level 2 can drop both.

How Players Beat Magma Mephits

• •Cold, not fire. It is immune to fire and vulnerable to cold. Burning Hands and Fireball do nothing. The Ray of Frost cantrip (1d8 cold at level 1) doubles to an average of 9. Cone of Cold is overkill but works.
• •Break Heat Metal. Damage the mephit to force concentration saves, or kill it. Magic Missile (three darts, 10.5 total) is reliable against a flying target. Dispel Magic ends a 2nd-level spell automatically.
• •Swap the weapon, not the armor. A heated sword is dropped on a failed save, and its owner can draw a backup. Armor stays on, so the only fix there is ending the spell.
• •Kill it at range. The Death Burst only reaches 5 feet. Bows and cantrips avoid it.
• •Watch for the lava pool. In a 2014 game, a "mound of magma" that doesn't move might be a mephit waiting.

Magma Mephit Encounter Ideas

The foundry. A dwarven forge's crucible is home to two magma mephits that have scared off the smiths. When the party arrives in armor, both cast Heat Metal on the first person through the door. The racks of finished blades give them more metal to heat if the party tries to swap weapons.

The volcanic vent. On a smoking hillside, three magma mephits guard a salamander's lair. They breathe from the vents and hide among the cooling rock.

The mephit swap. A rival party's wizard collects mephits. In the menagerie, a magma mephit's cage is next to the ice mephit's, and a steam mephit was born when they broke through. The dust mephit in the last cage is the one that let them out.

Frequently Asked Questions

What CR is a magma mephit?

A magma mephit is CR 1/2 (100 XP) in both editions. It has AC 11, with 22 hit points in the 2014 rules and 18 in the 2024 rules.

Can a magma mephit cast Heat Metal?

In the 2014 rules, yes: once per day, spell save DC 10, with no material components. The 2024 magma mephit has no spellcasting.

What does a magma mephit's Death Burst do?

When it dies, each creature within 5 feet makes a DC 11 Dexterity save, taking 7 (2d6) fire damage on a failure or half on a success. This is the same in both editions.

What is a magma mephit weak to?

Cold. It is vulnerable to cold damage and immune to fire and poison damage in both editions.

Stat blocks: System Reference Document 5.1 (2014) and 5.2.1 (2024), Wizards of the Coast, CC-BY-4.0. Tactics, encounter math and ideas are Loreify's own.