Mage's Antipathy (3.5e Maneuver)

"Ask yourself... do you really think your lips can get a spell off faster than I can stick my dagger in yer throat? Well, do ya punk?"

When you enter this stance, any creatures you threaten must make a concentration check with a DC of 15 + your initiator level + the spell level in order to cast defensively, instead of just 15 + spell level. You are considered to have twice your normal reach for determining how far you threaten for the purposes of spellcasting (so a medium creature with a sword threatens to 10 ft, and with a lance threatens to 20 ft).