Silly Mithral question

[BlackBart]

"Nonarmor or nonshield items made from mithral weigh half as much as the same item made from other metals."

However, Dwarven Plate weighs 25 pounds(1/2 of 50), Elven Chain weighs 20 pounds(1/2 of 40), Mithral Shirt weighs 10 pounds(more than 1/2 of 25), Mithral Large Shield weighs 5 pounds(1/3 of 15, though 1/2 of a large wooden shield).

So what's the deal? Does mithral affect the weight of armor/shields, as it appears(although not consistently) or not?

 

[rhammer2]

I believe that they rounded to the nearest 5 lbs.

"Nonarmor or nonshield items made from mithral weigh half as much as the same item made from other metals."

However, Dwarven Plate weighs 25 pounds(1/2 of 50), Elven Chain weighs 20 pounds(1/2 of 40), Mithral Shirt weighs 10 pounds(more than 1/2 of 25), Mithral Large Shield weighs 5 pounds(1/3 of 15, though 1/2 of a large wooden shield).

So what's the deal? Does mithral affect the weight of armor/shields, as it appears(although not consistently) or not?

 

[coyote6]

Yeah, they rounded down for simplicity.

You can always use the actual weights.

 

[BlackBart]

That explains the "inconsistent" values, but fails to address my main point. The DMG specifies that nonarmor or nonshields weight half as much, but what about armor and shields? Do they weigh half as much? It appears so, but then what's up with the statement regarding nonarmor/nonshields?

 

[coyote6]

IMO, it does. Though the rules don't quite make that clear, eh?

They do say, however, that armors are treated as one category lighter (heavy->medium, medium->light); given that, and the examples of mithral chain shirts, chainmail, and plate, I think it's clear that they intended mithral to make all mostly metal things lighter.

Magic of Faerun is nice and clear: "Mithral weighs half as much as steel."

 

[AuraSeer]

If you want to be pedantic about it, mithral wouldn't reduce armor weight by quite half, because armor isn't 100% metal.

Chainmail (or a chain shirt) is worn over a padded undergarment, which keeps the links from digging into the skin. Plate armor has all kinds of padding and straps which keep the whole thing balanced, connected, and reasonably comfortable. Even if the armor is made of mithral, the non-metal portions will not have their weight reduced. The result (mithral + "other") will weigh a little more than half the original (steel + "other").

So for a reasonable approximation, it does make sense to half the armor's weight and then round up to the next 5-pound increment. Or you could be less picky, go with exactly half weight, and pretend the weights in the book are typos.