I'd like to see metal armor divided into small, medium, and large. Every character would be separated into each category based off their weight and height. Wearing armor other than your size will give a penalty. You would need to visit a blacksmith and pay to have a piece of armor adjusted to a different size. Blacksmiths could also be commissioned to make specific pieces of armor (or metal weapons) for a little more than if you just traded for that same piece normally, and would take a few days to complete (longer for bigger/more complicated pieces). They could also repair your damaged metal armor, too.