It is stern work, it is perilous work, to thrust your hand in the sun,
And pull out a spark of immortal flame to warm the hearts of men

—Joyce Kilmer (1917) 'The Proud Poet', from Main Street and Other Poems

Sorcerous Origin: Volcanic Heart

The roaring fire of the volcano runs through your veins, overflowing in magmatic magics. Perhaps you or one of your ancestors were born in the vicinity of a portal to the Elemental Plane of Fire, your line was subject to an elemental curse, or perhaps you were the descendant of the union between a fiery elemental and a humanoid. Whatever the source of your power, you have inherited an innate connection to Elemental Fire in its purest form, and it burns within you, seeking release. By channeling this terrible flame, you can unleash explosive spells that purge your enemies in fire, burning away what is to create fertile soil for what will be. Be careful, though, lest the fire burn too hot and burn you up from inside.

Volcanic Magic

You know the fire bolt cantrip, and you learn additional spells when you reach certain levels in this class, as shown in the Volcanic Spells table. These spells count as sorcerer spells for you, and they do not count against the number of sorcerer spells you know. These spells can't be replaced when you gain a level in this class, except as detailed below.

Whenever you gain a sorcerer level, except the level you gained this feature, you can replace one spell you gained from this feature with another spell of the same level. The new spell must be an evocation or transmutation spell from the druid, sorcerer, or wizard spell list.

Table 1: Volcanic Spells

^EESpell from Evoke the Elements.

In addition, the elemental magic burning in your veins manifests as a physical quirk or magical aura. Consult the Manifestations of the Volcano table and choose or randomly determine a way this volcanic connection manifests, using the quirks in the table or those of your own creation.

Table 2: Manifestations of the Volcano

Affinity for Fire

The heat of magma burns in your veins. Sarting at 1st level when you gain this origin, you have resistance to fire damage. Once you reach 11th level, you are instead immune to fire damage.

Arcane Eruption

Also starting at 1st level, the volcanic energy within you empowers your spells with explosive volatility. When you roll fire damage for a spell, if you roll the highest value on any damage die for that spell, you can reroll that damage die, adding the number rolled to the fire damage dealt. If the new roll is also the highest value on that damage die, you may continue to reroll the die until you do not roll the highest value on that die, adding each new roll to the damage total.

Additionally, if you score a critical hit with a spell that deals fire damage, roll the damage dice thrice, instead of twice, when determining damage for that spell.

Igneous Mutations

By 6th level, your mastery over the heat of your flames allows you to reshape the world around you. Whenever you cast a spell of 1st level or higher that deals fire damage, you can expend 1 or more sorcery points to cause one or more of the following effects. If the chosen effect(s) apply to an area, it applies to the area of effect of the spell, or if the spell does not have an area of effect, the chosen effect(s) instead apply to a 5-foot-radius sphere centered on each target of that spell.

Afterglow (1 sorcery point). Until the end of your next turn, the area is flooded with dim light. If any of this area of light overlaps with an area of darkness created by a spell of the same level or lower than the spell cast to cause this effect, the spell that created the darkness is dispelled.

Heat Haze (2 sorcery points). You or a creature of your choice within 30 feet of you are surrounded by a mirage that obfuscates its position. Other creatures have disadvantage on attack rolls against that creature until the end of its next turn.

Molten Rock (1 sorcery point). You melt the surface of the ground, twisting it into new shapes. The area becomes difficult terrain.

Volcanic Ash (1 sorcery point). The area is filled with thick black smoke until the end of your next turn or until it is dispersed by a wind of moderate or greater speed (at least 10 miles per hour). The area is heavily obscured.

Feed the Fire

Starting at 14th level, the volcanic fire you channel becomes all-consuming. Spells you cast that deal fire damage treat immunity to fire damage as resistance to fire damage.

Additionally, if you would roll additional damage dice due to your Arcane Eruption feature, you can choose to remove one of those damage dice, roll it, and recover a number of sorcery points equal to half the number rolled, rounded up (min 1). You do not add this die to the damage roll, and you do not roll additional dice if you roll the highest value on it.

Volcanic Cascade

At 18th level, you learn to turn your fiery spells into magical chain reactions. When you cast a spell of 1st level or higher that deals fire damage, you can choose to retain a portion of that spell's magical energy. If you do, once before the end of your next turn, you can cast a spell of 5th-level or lower that deals fire damage and that has a level lower than the level of the spell you cast to trigger this effect, without expending a spell slot. If you do not do so, the retained magical energy dissipates in a burst of energy at the end of your turn, dealing fire damage to you equal to twice the level of the spell you cast to trigger this effect. This fire damage ignores resistance and immunity to fire damage, and it cannot be reduced or avoided in any way.