Improved Unarmed Strike( Player's Handbook v.3.5, p. 96)
[Fighter Bonus Feat, General]
You are skilled at fighting while unarmed.
Acheron Flurry (PlH) , Ascetic Hunter (CAd) , Ascetic Knight (CAd) , Ascetic Mage (CAd) , Ascetic Rogue (CAd) , Circle Kick (SF) , Clever Wrestling (CW) , Clever Wrestling (MW) , Clever Wrestling (SW) , Defensive Throw (CW) , Deflect Arrows (PH) , Eagle Claw Attack (CW) , Eagle Claw Attack (SF) , Earth Fist (RS) , Earth's Embrace (CW) , Exceptional Deflection (ELH) , Feign Weakness (SF) , Fiery Fist (PH2) , Fiery Ki Defense (PH2) , Fists of Iron (CW) , Fists of Iron (SF) , Flying Kick (CW) , Freezing The Lifeblood (CW) , Hammer Fist (Rac) , Holy Ki Strike (BoED) , Improved Grapple (DD) , Improved Grapple (PH) , Improved Grapple (Una) , Improved Stunning Fist (ELH) , Infinite Deflection (ELH) , Ki Blast (PH2) , Legendary Wrestler (ELH) , Martial Throw (MH) , Pharaoh's Fist (Sa) , Rattlesnake Strike (Sa) , Reflect Arrows (ELH) , Righteous Strike (ELH) , Roundabout Kick (CW) , Sanctify Ki Strike (BoED) , Scorpion's Grasp (Sa) , Serpent Fang (Sa) , Snap Kick (ToB) , Snatch Arrows (PH) , Snatch Arrows (SF) , Stonewalker Fist (Rac) , Stunning Fist (PH) , Sudden Willow Strike (PE) , Superior Unarmed Strike (ToB) , Throat Punch (CS) , Thunderclap (SS) , Toothed Blow (SW) , Versatile Unarmed Strike (PH2) , Vile Ki Strike (BoVD) , Vorpal Strike (ELH) , Water Splitting Stone (PH2) , Weakening Touch (CW) , Weapon Group (Monk Weapons) (UA) , Ascetic Psion (SoS) , Clever Wrestling (Dr) , Cunning Sidestep (Dr) , Cutpurse (DC) , Hammer Fist (DC) , Ring the Golden Bell (DC) , Paralyzing Fists (Gh) , Vile Ki Strike (ElE) , Forceful Staff Style (Gh) , Choke Hold (OA) , Defensive Throw (OA) , Eagle Claw Attack (OA) , Earth's Embrace (OA) , Empty Hand Mastery (OA) , Falling Star Strike (OA) , Fists of Iron (OA) , Flying Kick (OA) , Foot and Fist Mastery (OA) , Roundabout Kick (OA) , Freezing the Lifeblood (OA) , Grappling Block (OA) , Great Throw (OA) , Improved Grapple (OA) , Unbalancing Strike (OA) , Mighty Works Mastery I (OA) , The Gentle Way Mastery (OA) , Meditation of War Mastery (OA) , Paralyzing Fists (DrU) , Dragonmark Fist (Dra) , Hazing Strike (SoS) , Stunning Master (SoS) , Versatile Unarmed Strike (SoS) , Improved Stunning Fist (DMG) , Improved Stunning Fist (DMG) ,
You are considered to be armed even when unarmed — that is, you do not provoke attacks of opportunity from armed opponents when you attack them while unarmed. However, you still get an attack of opportunity against any opponent who makes an unarmed attack on you. In addition, your unarmed strikes can deal lethal or nonlethal damage, at your option.
A monk automatically gains Improved Unarmed Strike as a bonus feat at 1st level. She need not select it. A fighter may select Improved Unarmed Strike as one of his fighter bonus feats (see page 38).
Without this feat, you are considered unarmed when attacking with an unarmed strike, and you can deal only nonlethal damage with such an attack.