Ischaldirh wrote
If it's handled on a "took minimum percent damage", be aware that virtually every blow to the head will result in a scar.
No, my idea is not that if the hit takes more than the minimum percentage set it will always leave a scar. The minimum percentage is for the chance to roll, so if the damage dealt is more than the set percentage of the body part's hp, only then it would be a chance for it to inflict a scar. In any case, it can be tweaked but the main idea is to avoid super weak monsters leaveing scars through strong armor via critical hits.