X-Com: Gray Dawn Grazing

When you take a hit in combat, there is always a chance that any hit will only graze the target, dealing minimal damage. (It's only a flesh wound!). When a successful hit is made, roll for hit location. Apply damage vs. armor. If it penetrates, and the penetrating damage exceeds the minimal grazing damage (see below), make a graze roll (LK+1d10) vs. a target of 15 . If the target number is reached, the attack merely grazes the target, dealing a maximum of 1 point of damage/d6 base damage (any weapons that have +X damage still deal the +X). So, a grazing shot with a weapon that deals 4d6+1 will deal 5 damage. Weapons that deal d10 damage inflict 2 points/d10 on a graze. BTM still applies to this damage. With a BTM of -2, that 4d6+1 graze would cause a 3-point wound (which is a lot better than a 13-point wound)

Some weapons/ammunition types may have graze modifiers, meaning targets are more or less likely to avoid taking full damage from their attacks (for example, hollow point rounds will usually have a graze penalty, while armor piercing rounds will likely have a graze bonus). Head shots suffer a graze penalty of -2, hits to the limbs get a bonus of +2. If the attack just barely succeeds (attack roll is equal to or only 1 greater than the defense roll), there is a graze bonus of +1. Additionally, every full 5 points the defense roll is beaten adds a -1 penalty, as the attacker has skillfully (or by chance) struck closer to "center of mass" for whatever body location they hit. Generally, "mooks" will not make graze rolls.

Lucky characters are lucky for a reason. Grazing head shot damage exceeding the BTM does not inflict double points on the wound track.