(Combat)
You have learned how to land blows so painful it is difficult for struck spellcasters to concentrate.
Prerequisites
Vital Strike, base attack bonus +6,
Knowledge (arcana) 3 ranks.
Benefit
When you use
Vital Strike (or
Improved Vital Strike or
Greater Vital Strike), the creature you hit with the attack must treat the damage dealt as continuous damage until the beginning of your next turn. This forces the target to attempt a concentration check if it casts a spell . You can use this benefit twice per day, or three times per day if your base attack bonus is +12 or higher.