Fire Storm 5e: Cube Placement, Damage, and Objects

I like Fire Storm because its power is as much about drawing the right shape as rolling damage. Ten connected cubes can wind through a crowded battlefield, reach different elevations, and leave carefully chosen spaces outside the flames.

Fire Storm 5e — Quick Spell Reference

How Fire Storm Works in 2014 D&D 5e

You create sheets of flame in an area within 150 feet. Each creature in that area makes a Dexterity saving throw, taking 7d10 fire damage on a failure or half as much on a success. The average damage before a save or resistance is 38.5.

Fire Storm is Instantaneous and does not require concentration. It has only verbal and somatic components, so no material component or focus is needed.

Arranging Fire Storm’s Ten Cubes

The area consists of up to ten 10-foot cubes. You may use fewer than ten, and you arrange their positions, but every cube must share at least one full face with another cube. Touching only at an edge or corner is not enough.

Because each cube needs a face connection to the group, the area can form a line, bend around a corner, stack vertically, or branch. It cannot split into two disconnected fires. The flexible shape is the spell’s biggest advantage over a single sphere: you can route the storm through enemy spaces while leaving some allies outside it.

Does Fire Storm Damage Objects and Buildings?

Yes. The 2014 spell explicitly damages objects in its area. It also ignites flammable objects that are not being worn or carried.

The spell does not provide a single amount of damage for an entire building. Individual objects use the normal object rules, and the DM decides how a large or complex structure is divided into damageable sections. Worn and carried objects are protected from the ignition clause, but the spell’s wording does not turn creatures carrying those objects into valid object targets.

Can Fire Storm Spare Plants?

When you cast the 2014 spell, you may choose for plant life in the area to be unaffected. This is optional, so a druid can burn hostile terrain or protect a forest while striking other targets.

The rules do not define “plant life” inside the spell. Whether that protection also covers a creature with the Plant type is a reasonable question for the DM; the spell does not separately say “Plant creatures.” Decide that reading before resolving a crowded encounter where it matters.

Can Fire Storm Be Upcast?

No higher-level benefit is listed. An 8th- or 9th-level slot does not add cubes, increase damage, or extend the range. Casting it from a higher slot can still matter to effects that inspect a spell’s slot level, but Fire Storm’s own numbers do not improve.

For comparison, an upcast Fireball is less flexible in shape but does scale its damage. Choosing between them is about area control, available slots, resistances, and the exact battlefield rather than Fire Storm being an automatic damage upgrade.

Fire Storm: 2014 vs. 2024 Rules

The 2024 version keeps the action, 150-foot range, ten connected 10-foot cubes, Dexterity save, and 7d10 fire damage. Two environmental details change:

• The 2024 spell still ignites flammable unattended objects, but it no longer contains the broad statement that the fire damages objects in the area.
• The option to leave plant life unaffected is removed.

Fire Storm FAQ

Can Fire Storm make a wall of fire?

It can arrange its 10-foot cubes in a connected row or stack, creating a wall-like instantaneous blast. It does not remain as a lasting barrier like the Wall of Fire spell.

Does Fire Storm hurt allies?

Yes, if they are inside the chosen area. The spell does not let you exclude individual creatures; you protect allies by placing the cubes around them.

Does Fire Storm deal half damage on a successful save?

Yes. A successful Dexterity save halves the fire damage rather than preventing it.

Does Fire Storm require concentration?

No. It resolves instantly.