# Does a 10th-level wizard's fireball do 5d6 or 10d6 damage?

A player asked a question during last night's session and I honestly have no RAW knowledge for this.

During combat, a level 10 wizard (we started at level 10) cast fireball. The question was: Since fireball is gained at 5th level (spell level 3), when cast at 10th level do you roll 5d6 or 10d6?

She is wondering because it would be a huge difference in damage and how spells work.

Basically, is the caster level for a spell determined by the PC's caster level or by the number of caster levels above when the spell was gained? When you gain fireball at 5th level, do you roll 1d6 or 5d6?

## The Fireball spell does 1d6 die of damage per overall caster level starting at 5d6 at fifth level up to 10d6 at the caster's tenth level.

She should roll 10d6 for her fireball damage.

## The caster level for a spell is determined by the player's overall caster level.

A caster level is a character level taken in a character class that gains caster levels at a level and rate defined in their class description. See the rules on pg 171 of the PHB under the header CASTER LEVEL, and under each class that can cast spells.

For a straight up Wizard, Fireball Dmg starts out at 5d6 when you get the spell at a Wizard and Caster level of 5th, and, assuming you take your next level in Wizard, it goes to 6d6 because you gain another caster level with that Wizard level; 7d6 at 7th, etc. This continues all the way up to 10d6 at the 10th caster level where it caps out. Further caster levels gained will not increase the dice of fireball damage.

From the 3.5 PHB pg 231

A fireball spell [...] deals 1d6 points of fire damage per caster level (maximum 10d6) to every creature within the area.

Whenever the rules say "per (x) level" you can simply multiply by the number of relevant character levels of (x) to get the desired effect. In this case it states "per caster level" so you would count only character levels the PC took in the class that they are using to cast this spell (and any classes that specifically stack - see prestige classes in the DMG, pg 176 for starters) - and that is the number of d6 you then roll.

NOTE: This is for 3.5 rules. Things can be much different in other editions.

• Comments are not for extended discussion; this conversation has been moved to chat. Commented Jun 26, 2017 at 22:28
• Note: this applies when the character casts a spell from their own spell slots. Generally speaking, casting from an item (eg., a scroll or wand) will use the minimum caster level for the spell or will have an explicit caster level (eg., the 10th level wizard with a scroll of Fireball that has a caster level of 7 could use the scroll to cast a Fireball that deals 7d6 fire damage). There are items, feats, prestige classes, etc. that change this, of course. And staves - they use the higher of the staff's caster level and the wielder's. Commented Mar 25, 2021 at 14:55