Irritating Blow (3.5e Maneuver)

You hit the foe right in the face, hoping that he won't be able to finish his spell once you've lobotomized him.

You can initiate this maneuver whenever you would make an attack against a spellcaster in the process of casting a spell, as long as that attack is not part of another maneuver or a full attack. You can initiate this maneuver as part of an attack of opportunity or as a standard action. Make a single melee attack. If it connects, the attack does 4d6 extra damage, and is considered to have dealt three times as much damage as it actually did for the purpose of determining the Concentration DC to avoid losing a spell, power, or other such ability.