Your manipulation of spell power sometimes produces spectacular results.
Prerequisite: Caster level 9.
Benefit: When you roll a natural 20 (the die shows a ‘20’) on a concentration check to cast a spell, a dispel check, or a caster level check to overcome SR, you are considered to have scored a critical hit with that spell. You do not deal any additional damage, but you can increase either the spell’s save DC or your effective caster level by 2. You can add to your spell any effect you gain when you score a critical hit with an attack roll for a spell.