Bao-Dur's energy-arm (also known as a repulsor fist or, more accurately, repulsor arm) was used as a replacement for his left arm, after it was lost at Malachor during the Mandalorian Wars. Cyan-colored energy flowed between the top part of the arm to the bottom. The arm was very strong, as it could break through any force fields, and it would also occasionally discharge stored energy into the enemy on contact, somewhat like a built-in energy baton.
Bao-Dur's energy arm can also be used in combat to take down any personal energy shields being used by an enemy in the game. As he levels up, he gains additional feats which magnify that ability, yet it is not a passive power when used in combat and must be selected like any other special attack. A second line of feats governs the additional damage applied by his arm in unarmed combat, which is unique in that when added to the skill in unarmed combat provided by jedi training, he gains more damage bonuses in unarmed combat than any other character.
- Knights of the Old Republic Campaign Guide