You can cast spells with exceptionally great effect.
Prerequisites: Empower Spell, Maximize Spell, Spellcraft 30 ranks, ability to cast 9th-level arcane or divine spells.
Benefit: All variable, numeric effects of an intensified spell are maximized, then doubled. An intensified spell deals twice maximum damage, cures twice the maximum number of hit points, affects twice the maximum number of targets, and so forth, as appropriate. Saving throws and opposed rolls are not affected.
Example: An intensified horrid wilting spell would deal 12 points of damage per caster level (up to a maximum of 240 points of damage at 20th level). Against plant creatures and water elementals, this would be 16 points per level (maximum of 320 points).
An intensified spell uses up a spell slot seven levels higher than the spell’s actual level.
A character can’t combine the effects of this feat with any other feat that affects the variable, numeric effects of a spell.
Source: Standard Reference Document under Open Game License v1.0a, which updated this feat originally published in the Epic Level Handbook, page 61. Corrected the example intensified horrid wilting spell for version 3.5.