Just found this on another forum and I gotta say I thought it was a very interesting take on Armor Class in a Low-Armor (or more S&S) setting. Here's the house rule for those not wanting to make the trip.
The interesting part of this is that the classes appear to account for "armor proficiency" using the base AC. I'd consider expanding the armor selection a bit... perhaps light armor +2, medium armor +4 and heavy armor +6 -- I think those bonuses reflect the leather/chain/plate distinctions much better. Plus it allows for shields and breastplates to add in +1 here and there.From Morandir
What I do is have the base AC vary by class. Fighters are 5(14), Clerics/Thieves 7(12), and MUs keep the standard 9(10). Light armor (defined however you want) improves AC by 1, medium armor by 2, and heavy by 3. Shields add 1.
Depending on the attribute bonus structure, I might consider knocking the base ACs down. They seem a bit on the high side in a game where you could get +3 or +4 to Armor Class out of the gate. But I honestly don't know what I'd knock them down to. Or if I'd even worry about it.
But, as is, Morandir's Armor Class rule makes for a situation where you could have a Fighter running around in a loincloth ala Conan, Kane or several others. And run a setting where Plate Mail costs as much as it really probably should -- without completely hosing the characters. It just seems very applicable to Appendix N.
Not knowing (or saying) DCC needs anything like this. But I think it's clever and simple. It may become a house rule for me at some point. We'll see on that.