Feeblemind

8th-Level Enchantment
Casting Time: 1 action
Range: 150 feet
Components: VSM (a handful of clay, crystal, glass, or mineral spheres)
Duration: Instantaneous

You blast the mind of a creature that you can see within range, attempting to shatter its intellect and personality. The target makes an Intelligence saving throw.
On a failed save, the creature takes 10d12 psychic damage, and its Intelligence and Charisma scores become 1. The creature can't cast spells, activate magic items, understand language, or communicate in any intelligible way. The creature can, however, identify its friends, follow them, and even protect them.
At the end of every 30 days, the creature can repeat its saving throw against this spell. If it succeeds on its saving throw, the spell ends.
The spell can also be ended by greater restoration, heal, or wish.
On a successful save, the target takes half damage and no additional effects.
At Higher Levels. When you cast this spell using a spell slot of 9th level or higher, you can target an additional creature for each slot level above 8th.

Source: PHB 239, SRD

Changelog