OK, rather than just flip out

, let me offer my revision. Please reference the below image I quickly threw together. A couple notes:
* "tactical vests" don't offer any protection on their own. That's not what a tactical vest does. It's meant to carry your gear and typically made with lightweight webbing to allow your body to breathe.
* the famous "dragonskin" body armor is certified at level III. It's not some super uber body armor.
* body armor is divided into levels. See the image to see what sort of protection each gives.
So...
Knowing that AC is abstract in D&D, we really can't go with the realistic "if armor = X and weapon fired is from a pistol, ignore all damage, but if fired from a rifle caliber, then no damage is ignored, yada yada yada." That gets too complicated and is too much to remember. So my suggestions?
* No armor gives disadvantage to stealth. each plate is in an individual pocket and it doesn't make any more noise than your regular clothes.
* due to weight and encumbrance, I would give a max DEX bonus of +2 for level III or higher armor. Remember that level III and IV don't weigh that much different or carry different in any appreciative value. They are just made from different materials
* Level II armor gives DR2, Level III gives overall resistance, Level IV gives resistance or DR10, whichever is higher.
And be done with it.
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