Staggering Fist

(Combat)
When you engage in unarmed combat, you know just where to strike to stagger your foe.
 

Prerequisites

Dexterity 13, Wisdom 13, Improved Unarmed Strike, base attack bonus +2.
 

Benefit

When you damage a foe with your Unarmed Attack, you can also cause it to be Staggered for 1 round (until just before your next turn). The target can avoid this with a successful Fortitude saving throw (DC = 10 + 1/2 your character level + your Wisdom modifier). You must declare that you are using this feat before you make your attack roll; thus, a failed attack roll ruins the attempt. You can attempt to use this feat once per day for every 4 character levels you have, but no more than once per round. Constructs, Incorporeal creatures, plants, undead, and creatures that are immune to critical hits cannot be affected by this ability.
 

Combat Trick

If you have a Stamina pool, the following Combat Trick may be used with this feat.
  You can spend 5 Stamina points to declare that you are using this feat after you’ve hit with an unarmed strike.
 

Required For