Mage Slayer

(Monster Manual V, page 85, DnD 3.5)

[General]

You have studied the ways and weaknesses of spellcasters and can time your attacks and defenses against them expertly.

Prerequisite

Spellcraft 2 Ranks, Base Attack Bonus +3

Benefit

You gain a +1 Bonus on Will saves. Spellcasters you threaten cannot cast defensively (they automatically fail their Concentrattion checks if the attempt to do so), but are aware that they cannot cast defensively while being threatened by you.

Special

Taking this feat reduces your caster level for all spells and spell-like abilities by 4.