First, in fantasy fiction, the archetypal Dwarven stronghold is a mine, or is built around or above mines. How would this factor into an ACKS Dwarven Vault? Would the mines be included in the cost of the Vault stronghold, or be a separate part (essentially part of the 6-mile hex value?
Second, in the Auran Empire or similar settings, is Mithral a naturally-occurring alloy, or an artificial one? If it is artificial, what metals is it composed of?
In my view, it’s something that rulers of a dwarven vault would do instead of trading.
As far as I could tell by reading ACKS, there is no mithril or other fantastic metals in the Auran Empire. There’s no mention of it in the magic item chapter and there’s no elven chain. My rules include mithril because they’re based on the Complete Book of Dwarves.
There is no mithral, that being a purely Tolkienesque invention. I wanted all the fantasy metals to be rooted in ancient Hellenistic or Indo-European myth.
Magical metals in ACKS therefore include:
meteorite iron (sky-steel)
adamantine (ore from deep in earth)
orichalcum (white bronze; copper, gold, and adamantine)
“Corinthian bronze” (with an appropriate renaming) could also be used. Per Pliny, there were three grades - copper alloyed with silver, copper alloyed with gold, and an equal blend of copper, silver, and gold. They were considered more valuable than hepatizon because of the higher proportion of precious metal.