The Human Target said:
I agree with all that. But Dragonlance is/was a Points of Light setting. And the people in it commonly used steel coins because steel was much more important in their difficult gritty lives than gold. They melted the coins down into armor, and weapons, and tools. Thats why it fits.
Except that that pretty much ignores the whole process of manufacturing steel in medieval society. Making steel by hand is a very labor-intensive process. It'd be idiotic, especially for people leading such dirt-poor lives, to make the steel into coins, and then go through the whole process again to turn the coins into weapons and armor. Besides, they didn't have stainless steel back then. The stuff would rust. If it was being passed from hand to hand, getting exposed to skin oils all the time, it'd rust very quickly.
If you were going to use steel as a unit of currency, you'd just trade in steel goods directly. Much more likely, you'd just stick to using gold, silver, and copper. If your life was so difficult that you couldn't spare the labor to make new gold/silver/copper coins, you'd just use the ones already in circulation (and the value of those coins would shoot up).
The Human Target said:
As to the how, sure it may have been hard in Medieval times. But in DnD we have people that can do magic to alter the physical world and have craftsmen that can create amazing fantastical creations. Its not too hard to think of them being able to mint neat steel coins.
First off, if they have the considerable magic required to make steel coins economical, why are they wasting it on steel coins? Why not use it for something that would help them in their "difficult, gritty lives?"
Second, who is working all this magic? Are there wizards someplace churning out Mordenkainen's Easily Reforgeable Non-Rusting Steel Coins? If so, how come the Knights of Solamnia aren't boycotting the heck out of them? It's certainly not clerical magic, since that vanished with the Cataclysm and it was after the Cataclysm that the steel coin system got started.
Third, this argument boils down to "a wizard did it," which is something of a cop-out.
Bottom line, having steel coins as a widespread form of currency requires a serious rethinking of the economic system--the magic "technology" involved would surely have some major ramifications beyond simple coinage.