Firestorm

Spell — see Magic and Spellcasting for the rules and the Spell Index for the full list.

Arcane 5 Type: blast, elemental (fire)

Range: 225’ Duration: instantaneous

The caster conjures a storm of burning alchemical naphtha 20’ in diameter centered on a target point. Each creature within the firestorm must make a Blast saving throw. If the save fails, the creature suffers 1d6 extraordinary fire damage per caster level and is engulfed in burning naphtha. If the save succeeds, the creature suffers half that damage but is not engulfed.

A creature engulfed in burning naphtha fire suffers an additional 1d8 extraordinary fire damage at the start of its initiative each round. At the end of its initiative, it must make a Blast saving throw. If the save fails, it continues to be engulfed next round. If the save fails, the alchemical naphtha sputters out and the creature takes no further damage. The alchemical naphtha cannot be put out by immersion in water, but a counterspell can extinguish it on one creature or object and a dispel magic can dispel the entire fire.

Like a fireball, a firestorm can also damage structures in its area of effect. It deals up to 1d6 extraordinary fire structural damage per caster level to wood structures and one-third that to stone structures. (It might deal less if the structure is not entirely in its area of effect.) It causes combustibles (such as military oil or petards) to ignite. Thereafter it deals 1d8 extraordinary fire structural damage to wooden structures and one-third that to stone structures until the fire is put out. The structure can save as a 0th level fighter each round.