A character in my ongoing Exalted 2e game has an artifact chain shirt. Artifact chain shirts are described as being able to be worn under ordinary clothing (it has no mobility penalty or fatigue value). He's also recently acquired a (non-artifact) reinforced breastplate. He'd like to wear them both. I don't see any rules describing whether this can be done, what net protective effect it would have, or what effect it would have on mobility and fatigue.
Can multiple types of armor be stacked? How would I adjudicate this?
The character in question is pretty fragile so I'm not entirely opposed to his getting some kind of benefit, but I worry about setting a precedent that will bite me later.
Best Answer
Sure, provided you can reasonably get on more armor on top of it
As far as I am aware, there is no rule against stacking armor provided you can physically put it on. Plus, The Scroll of Errata (p. 43) points out the following about tattoo armor:
There are a couple of things to remember when doing this though (Assuming an Orichalcum Chain Shirt):
Hardness does not stack with any other hardness
So you'd just take the higher value. (The 3L/3B from the artifact chain shirt since Regular breastplates have none).
Mobility Penalties are internal penalties, and penalties can stack
So the two armors would stack their mobility penalties, (Not that a chain shirt has one).
They also presumably would add their fatigue values together (1 from the Breastplate, 0 from the chain shirt), though you could make the argument for 2 fatigue rolls (I'd go with stacking them).
Soak Would Stack
So you're looking at +11L/7B (+4L/2B from the breastplate + 7L/5B from the Chain Shirt).
All in all, you're looking at something that is worse (In soak by a little, hardness by far) than an Orichalcum Reinforced Breastplate, For 1 dot in Artifact and 1 dot of Resources. That's not overpowered. Just don't let them get the idea that they can summon demons to act as armor and wear that underneath power armor...