Piercing wounds and vital organ hits
I've never really gotten how an attack called 'arrow STAB' can 'slash' or 'cut' the upper chest of my enemy. Makes it sound like I used the arrow as some kind of sword. Same goes for bullets, arrows used for their intended purpose, and spears.
So, my suggestion: Piercing damage. When your character gets hit with a stabbing/piercing attack, it will leave a puncture wound on wherever your character was hit. Puncture wounds will generally not bleed as much as a cutting weapon, but will have a chance of hitting certain vital organs, making them deadly if aimed in the right place.
Heart. Instead death if heart is hit by a piercing attack. Has a medium chance of happening if character is shot/stabbed in the lower chest.
Brain: Instant death if brain is hit by a piercing attack. Has a very high chance of happening if character's head is shot or stabbed.
Lungs: Not instant death if character's lungs are hit, but character will instead recieve a 'Punctured lung' status, which will also immediately grant the 'Coughing blood' and 'Internal bleeding' status (if they haven't been already granted). Having a punctured lung will, besides causing a fair amount of pain and internal bleeding, take a very long time to heal, assuming the character survives the healing process. That being said, Nanobots can also be used to help heal a punctured lung. Character has a moderate chance of getting a punctured lung if shot or stabbed in the upper chest.
Weapons and Attacks that can utilize piercing attacks (some already exist, some are new ideas):
-All guns when firing bullets
-Arrows, both when fired from a bow and when using the 'Arrow stab' attack when using it as a melee weapon
-Spear stab and spear throw attack, for all spears
-Multitool Blade: Knife stab*
-Broken Bottle and Glass Shard: Bottle stab and shard stab*
-Enemy dogmen can use their claws for a piercing attack*
*Weapon can alternate between cutting and stabbing attacks
In addition, as armor values have already been added for clothing items, I suggest armor piercing values for piercing weapons. The potential for a gun to penetrate, say, a very heavily clothed enemy, would depend on the calibre of gun and the range from where it's being shot. For example, using a .45 handgun at maximum range would be less likely to pierce the armour than firing a military shotgun from three meters away.
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