Distort Speech

(Complete Adventurer, DnD 3.5)

Transmutation[Sonic]

Level: ; Bard 1; Vigilante 1
Components: V, S
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature
Duration: 1 round/level
Saving Throw: Fortitude negates
Spell Resistance: Yes

You distort a creature's vocalizations.
The voice of the subject becomes warped and nearly incomprehensible.
For the duration of this spell, the subject has a 50% chance to miscast spells that have verbal components, and any time the subject speaks (including the use of magic items activated by command words), there is a 50% chance that the utterance is completely incomprehensible and therefore ineffective.