Motion capture reactions. Including a wide variety of believable responses in the motion library is important for producing highquality results. To create our library, we recorded two actors sparing and practicing kenpo and judo strikes and recoveries using optical motion capture equipment. We mapped the recorded data to our character with a physically based model [Zordan and Horst 2003]. Our full repository contains segmented strikes and pushes as well as various reactions based on contact varying from light to heavy. While reactions to full contact strikes were omitted during recording to avoid injury, strong pushes were performed without harm to the actor. Pushes were made from the front, side and back with reactions including balanced recovery that required minimal foot repositioning, recovery requiring a leap or step, and complete loss of balance requiring a forward or backward judo-style somersault. Strikes included various kenpo-style kicks and punches. In total, our library contains 110 single-actor files which ranged from 3 to 10 s each. In the results shown, our system often found close matches between previously unmatched push reactions and strikes.