[Kromm]

The intent of the rule is to use the damage of the attack being parried. The weapon might be some Swiss Army knife with 100 attack forms, but the attacker has to pick one before rolling to hit. Use the damage of that attack form.

Those who dislike the size of the damage – and I agree it's excessive – might want to reduce Parrying Unarmed Attacks (p. B376) to a special case of Hurting Yourself (p. B379). First, don't limit self-inflicted damage to target DR. Second, change damage type to that of the edge of whatever you're parrying (cutting for anything with a swing cutting attack, crushing for just about everything else, and possibly burning or corrosion for energy swords), and remember that minimum damage is 1 point if the type is anything but crushing. Finally, apply any armor divisor on the weapon.

This is strictly a replacement for Parrying Unarmed Attacks (p. B376). Parrying Unarmed (p. B376) wouldn't change, because that's about mistiming a parry with your body and placing a body part directly in the path of a full-powered attack.