Aleval School

(Drow of the Underdark, page 56, DnD 3.5)

[Style]

You have learned House Aleval's fighting techniques, allowing you to deal damage that weakens your enemy's physical or mental state.

Prerequisite

Weapon Finesse, Spellcraft 2 ranks, Base attack bonus +4, Sneak attack +2d6

Benefit

When you deal sneak attack or sudden strike damage, you can sacrifice 1d6 points of this extra damage to bestow a --2 penalty on one of the target's three saving throws (your choice) for 1 round. You can use this feat once per round.