Disrupting Shot

Combat

With a well-placed shot, you make it harder for a nearby opponent to cast spells.

Prerequisite: Dex 13, Point-Blank Shot, fighter level 6th.

Benefit: If you ready an action to shoot an opponent casting a spell within 30 feet and successfully hit that opponent with a ranged attack, the concentration DC to successfully cast the spell is increased by +4. Disruptive Spell (Metamagic) Your magical energies cling to enemies, interfering with their spellcasting.

Source: Advanced Player's Guide