Attacking each region causes a primary effect, a possible proc, and an effect if the targeted region reaches critical condition.
Attacking the head and torso regions can eliminate 100% of a player's total hp. Each leg and arm region can only account for 20% of a player's total hp each (for a total of 80%). Players can lose any amount of hp from bleeding that results from wounds to the limbs. This simulates that attacking a player's arm, while decimating the arm, will not directly kill them. Even if all a player's limbs are decimated, they will still not die directly from further blows to the limbs.
If either arm or leg is in critical, the player is unable to make attacks or defenses tied to that limb (it's useless). Any body part in critical cannot be healed with bandages and herbs can only restore it to 50% without bedrest.
Different body parts are more difficult to hit, and/or more protected by armor. Attacking the enemy's head damages their hp and balance and can stun or knock them unconscious, but it is very hard to hit and heavily armored.
The chance for all possible procs is equal to two times the % damage done (or that would have been dealt for appendage shots). For example, a leg attack that resulted in the victim losing 15% of their hp would have a 30% chance to cause Off Balance. A leg attack that caused 30% damage (only resulting in the victim losing 20% of their hp) would have a 60% chance to cause Off Balance.