Freezing the Lifeblood

(Oriental Adventures, page 62, DnD 3.0)

[General]

You can paralyze a humanoid opponent with an unarmed attack.

Prerequisite

Improved Unarmed Strike, Stunning Fist (or monk's stunning attack), Base attack bonus +5, WIS 17

Benefit

Against a humanoid opponent, you can make an unarmed attack that deals no damage, but has a chance of paralyzing your target. If your attack is successful, your target must attempt a Fortitude saving throw (DC 10 + 1/2 your level + your Wisdom modifier). If the target fails this saving throw, he is paralyzed for 1d4+1 rounds. A paralyzed character stands rigid and helpless, unable to move or act physically. He has effective Strength and Dexterity scores of 0 but may take purely mental actions. Using this feat uses up one of your stunning attacks for the day (either a monk stunning attack or a use of the "
Stunning Fist":feats/players-handbook-v35--6/stunning-fist--2802/ feat).