Exhaustive Casting (3.5e Feat)
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Exhaustive Casting [Metamagic Feat]
Allows you to spend more energy to make your spells harder to resist.
Benefit: You may choose to cast any spell, spell-like ability, or extraordinary ability (so long as it has a cost) at two times its normal cost (uses 2 uses of spells per day rather than 1 use). When you do this, add the spell level and the casting stat used to the original save DC against the spell's effects. This does not use a higher spell slot than normal. Save DC = 10 + 2 * Spell level + 2 * Casting stat.
Normal: A spell uses one use per cast. Save DC = 10 + Spell level + Casting stat
Special: For spells with an attack roll, the bonus is applied to the attack roll, adding the spell level and the casting stat to it.