Touch of Idiocy

(Player's Handbook II, page 24, DnD 3.5)

Enchantment (Compulsion) [Mind-Affecting]

Level: ; Duskblade 2; Beguiler 2
Components: V, S
Casting Time: 1 standard action
Range: Touch
Target: Living creature touched
Duration: 10 min./level
Saving Throw: No
Spell Resistance: Yes

With a touch, you reduce the target's mental faculties. Your successful melee touch attack applies a 1d6 penalty to the target's Intelligence, Wisdom, and Charisma scores. This penalty can't reduce any of these scores below 1.

This spell's effect may make it impossible for the target to cast some or all of its spells, if the requisite ability score drops below the minimum required to cast spells of that level