Lunatic (3.5e Feat)
From D&D Wiki
Through some trauma your mind is shattered into pieces... the voices in your head mess with your thoughts, but also make it difficult for magic to bind your will.
Prerequisite: Cha 13
Benefit: If a person with this feat is affected by an enchantment spell or effect and fails her saving throw, she can attempt it again 1 round later at the same DC. She gets only this one extra chance to succeed on her saving throw. On the downside, any confusion effect that does go through lasts as if the caster level was 1 higher, as the mental voices have difficulty sorting themselves back out.