So, I have a player who wants to slap some light armor - most likely silken cermonial to avoid spell fail chance - on her sorcerer. Of course, she's disinclined to burn a feat on light armor proficiency.
Now, scouring the rules, this is the only thing I found on armor non-proficiency drawbacks:
Nonproficient with Armor Worn: A character who wears armor and/or uses a shield with which he is not proficient takes the armor's (and/or shield's) armor check penalty on attack rolls as well as on all Dex- and Str-based ability and skill checks. The penalty for non-proficiency with armor stacks with the penalty for shields.
If I am reading that right, that'd mean there's no reason for any wizard or sorcerer not to throw on some armored kilt, haramaki or silken ceremonial armor for some free AC, especially on the lower levels when enchated robes are not yet a concern.
Am I missing something?
Haramaki and Silken Ceremonial are the only 2 armors that i know of with 0% spell failure and no Armor check penalty.
I do believe there are ways to reduce spell failure on armor, but I can't remember them right now.
But ya, in a nutshell, a wizard/sorcerer/or any caster can wear Haramki without a problem (they don't need to be proficient with it since the Armor check penalty is 0).
I'd rather cast Mage Armour for +4 for a whole hour, that's 45 minutes more than you'll usually need it for ;)
This is a valid strategy for getting a little AC at low levels. At higher levels it can also be enchanted to provide a cheaper way to advance AC than bracers of armor. The two drawbacks that I can think of to this approach are that it won't help your AC against incorporeal touch attacks the way Mage Armor would and wouldn't interact well with Monk levels.
On a similar note, leather barding is kind of a "freebie" for animal companions and familiars though it would likely need to be custom made and tailored. I guess that even studded leather would be ok for this purpose once it is of at least masterwork quality.