Hi,
I've been thinking about this quite a lot, much more than would be reasonable. I was thinking about the economy, starting from these three things:
[CURRENCY:COPPER:1]
[CURRENCY:SILVER:5]
[CURRENCY:GOLD:15]
First, considering modern prices, that's a pretty wild ratio. Ratios of current prices would be something like 1-85-7500. I know DF isn't exactly supposed to reflect modern prices, but it seems bit silly anyway.
Also, it's always kind of bugged me that - with the economy disabled - copper coins are worth less than one dwarfbuck. Yet something like, say, an olive pit is worth one dwarfbuck. Pits are literally useless, yet copper is one of the most useful materials in the world. Isn't that what should define value; if it's good for anything? And after that, supply and demand. Surely, based on its usefulness alone, copper should be much more valuable than a pit.
Thus, firstly, the material values of metals should be increased dramatically. But even with that being done, it dawned to me that value is cultural. Surely dwarven civilizations should adore metals even more than anyone else. And a dwarven civilization whose home mountain has huge abundances of, say, nickel, tin, zinc and gold, but no copper, would value copper even more, as none of their common metals are weapon/armor grade. Heck, would they even know about those things before making contact with other civs? Also, with no access to copper or silver, their currency should be something different as well.
Similarly, a civilization whose main god is a god of lead would probably hold lead in very special regard. Or a warlike civilization would disregard ornamental materials and only value weapon/armor grade stuff.
And what about elves? They, too, have the default currency tokens. But they're supposed to hate metals. Why would their currency be based on them? In human history, lots of various things have had a sort of monetary value, including stuff like animals skins or furs, mollusk shells, whale teeth, etc. Knowing elves, they'd maybe prefer something like pearls, gems, or maybe stuff like seeds and fruit, over coins. What about goblins? Elf ears? Dwarf noses? Human bone necklaces?
So, the values of a culture should largely determine material values for their culture. And in turn, those should probably affect how those cultures develop. Say, a culture who worships gold could want to focus on acquiring more gold, either by founding new sites on gold-rich places, or perhaps even by conquest. Or a civ who values pearls could want to start an outpost at a place with pearls (once oysters and mussels actually provide pearls somehow).
And on a more general note, maybe cultures could and should diverge more from the basic archetypes. I know it happens to some extent, but still. Or maybe cultural spin-off things, like cults, guilds, etc., could take things even further.
But to return to what got me started, coins... I can't think of a reason why cultures shouldn't have distinct or even unique currencies. Just take a bunch of available (preferably non-weapon grade) alloys and go wild. Maybe even add a couple of fictional ones just for the sake of it. Frankly, for a project as complex as Dwarf Fortress, sticking to plain copper-silver-gold is way too straightforward. Just look at
old English money. A pound is 20 shillings. A shilling is 12 pennies. A penny is further divided to two halfpennies or four farthings (quarter pennies). Then there's threepence and sixpence (coins worth three and six pennies), groat and half-groat (four and two pennies)... And florin (two shillings), crown (five shillings), half-crown (two shillings and 6 pennies), half-sovereign (ten shillings), half-guinea (ten shillings and six pennies)... And guineas themselves were worth 21 shillings, which is one shilling more than pound itself. When reality's been this funky, I want to see a currency system like this:
[CURRENCY_BY_YEAR]
[CURRENCY:NICKEL:1]
[CURRENCY:ZINC:2]
[CURRENCY:PEWTER_FINE:4]
[CURRENCY:PEWTER_LAY:5]
[CURRENCY:PEWTER_TRIFLE:7]
[CURRENCY:COPPER:15]
[CURRENCY:BRASS:20]
[CURRENCY:BRONZE:25]
[CURRENCY:BILLON:60]
[CURRENCY:SILVER:100]
[CURRENCY:ELECTRUM:2500]
[CURRENCY:GOLD:5000]
Philosphical concernsWhat if a dwarven civilization has no access to weapon grade materials? How will they get picks?
Well, if they have gods, just give them a few picks made of that god's divine material. This also solves
the paradox of the original anvil. In fact, give them a couple of anvils of divine materials regardless of whether they start with iron. Wars sparked over those artifacts would be fun.
TL;DR: - cultural preferences should determine how much they value items and material (+ supply and demand on top of that)