You are tough enough to shrug off magic effects.
Benefit: Once per round, when targeted by a spell or effect that allows a Reflex save or a Will save, you can instead make a Fortitude saving throw. You may use the ability a number of times per day equal to 3 + your Constitution bonus.
Special: If you have this feat and gain a caster level, you may immediately decide to permanently forgo any spellcasting ability and retain this feat. If you do not make this decision this feat is lost, and cannot be replaced.
Adventurer’s Handbook: Genius Guide Volume 1. Copyright 2010, Super Genius Games. Authors: Owen K.C. Stephens and Stan!