Weird history here:
Core, Non-FR PnP Druid:
http://www.d20srd.org/srd/classes/druid.htm
Druids are proficient with light and medium armor but are prohibited from wearing metal armor; thus, they may wear only padded, leather, or hide armor. (A druid may also wear wooden armor that has been altered by the ironwood spell so that it functions as though it were steel. See the ironwood spell description) Druids are proficient with shields (except tower shields) but must use only wooden ones.
A druid who wears prohibited armor or carries a prohibited shield is unable to cast druid spells or use any of her supernatural or spell-like class abilities while doing so and for 24 hours thereafter.
...
OK, the SRD core druid can't even wear Studded Leather, funny eh? Some places out in the wild and wooly internet, it is explained (or theorized) that studded leather isn't just a set of leather armor with funky little buttons on it, those buttons actually attach to something beneath the visible leather, and that's little squares and whatnot of metal, essentially this is
brigandine armor. Looks leathery, has a lot of little metal studs apparent on it, but poke it and find out "there be metal in here, lots of it." Think modern flak jacket, they sure do look like bulky fabric things, but sandwiched within are lots of plates of "something", kevlar, weird composites, I suppose metal in some older stuff, don't know.
Anyhow, over to Forgotten Realms, yeah, there is that loophole for Mielikki folks. So PnP FR = go for it.
Over then to ALFA, transition screen load tips tell me constantly that "yeah yeah, PnP Mielikki druids can wear metal, not permitted in ALFA." Running searches of the forums I can occasionally come across a reference to this "metal armor flexibility" being revoked, but I can't locate precisely when, or why. I do not recall what rule we had in NWN1 either, or if maybe "freedom in NWN1 was abused" or something. Routinely you'd have DMs granting requests for full plate druids anyhow, with "uh, your armor is made of wood... and uh, it's also 50% weight because I say so", which caused a lot more discipline on special materials this time around, but that's a separate point.
So yeah, the metal armor thing in ALFA seems to have been decided, I am not sure why.
On the plus side though, no one seems to obey or enforce the "no studded" thing from the SRD in ALFA, choice of gods completely aside? Either due to not knowing that's in the SRD, or saying to themselves "leather, good enough!"
Remember that the druid spell list has a lot of excellent Natural Armor spells that other classes lack, plus the shapeshifting business which makes armor less and less useful (but the Natural Armor buffs extremely useful), so I can at least see "some" reasons for the balancing in SRD version at least, still a little scratching my head over the "free pass" from FR not being any good for Mielikki sorts in ALFA.
Those deeply craving higher AC could always pursue stuff like duskwood breastplates or hunting for dragons, really big ones with really useful components for dragoncraft (scales not hides) armor.
EDIT - or could just revisit the rule. Including maybe even "keeping the rule", but having your own self-inflicted penance of no using spells etc. for 24 hours if you cave in to the allure of chain armor for some desperate battles!
