Greater Spell Focus
From Compendium of Worldly Lore
Needs review
Source: Player's Handbook
Description: Your spells of your chosen school are now even more potent than before.
Prerequisites: Spell Focus
Required for: Epic Spell Focus
Add +1 to the Difficulty Class for all saving throws against spells from the school of magic you select. This bonus stacks with the bonus from Spell Focus.
Special
You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new school of magic to which you already have applied the Spell Focus feat.