Delayed blast fireball

Caster Level: Wizard / Sorcerer 7

'Innate Level: 7

School: Evocation

Component(s): V, S

Range: Medium

Save: Reflex Â½

Spell Resistance: Yes

Immunity Type: Fire

Area of Effect/Target: Huge

Duration: 1 Round / 3 Levels

Description: The caster creates a small, magical zone that can detect the passage of enemy creatures. When the field is activated, it explodes, doing 1d6 points of fire damage per caster level to all within the area of effect, to a maximum of 20d6.
 * Level 13 13d6 damage
 * Level 14 14d6 damage
 * Level 15 15d6 damage
 * Level 16 16d6 damage
 * Level 17 17d6 damage
 * Level 18 18d6 damage
 * Level 19 19d6 damage
 * Level 20+ 20d6 damage