So what nonstandard coins do you use in your games if you use nonstandard coins?
I don't like platinum, so I replace it completely with mithril pennies.
Coins start with copper pennies, silver pennies, golden pennies and then mithril pennies. Larger gold coins exist (the size you'd see in Pirates of the Carribean) and are called 'gold doubloons' or 'gold sovereigns.' (and yeah, they aren't 'double' anything, it's just a name). Each gold sovereign is worth 10 gold pennies (or 1 mithril penny).
Halflings and elves generally use mithril pennies as their highest denomination. Humans use gold soveriegns. Dwarves blow right past mithril pennies and also use adamantine bits (which are shaped like little pyramids and are worth 10 mithril pennies or 100 golden pennies).
Dwarves prefer alloyed coins, using electrum, brass, bronze, etc. but other races tend to shun them.
Gnomes use a ridiculously complex system, contantly changing as values fluctuate and news of the 'new value' are disseminated from gnomish moneylender to gnomish moneylender, based off of alchemical metals, with the usual copper, silver and gold, but also flasks of mercury for 25 gp denominations. Pretty much every other race uses a flat value, and doesn't bother with the 'gnomish nonsense,' although someone who plays the system can make (or lose) a fortune on speculating the gnomish coin exchange.
Parallel to adamantine bits are coins of orichalum, a warm reddish-gold in color, crafted by ancient wizards. In ye olde days, powerful wizards would craft these coins (supposedly from 'pure magic') and each one represents a single spell level of arcane spellcasting services (generally worth 100 gp). These coins were used as a form of payment from a powerful society of wizards, with anyone being able to redeem these coins for arcane spellcasting at a later date, but the wizards society is long dead. Still, the coins retain their value, and even if they can't always be redeemed for spell services, they are still considered to be worth 100 gp each. A unique property of orichalum coinage is that any arcane spellcaster can place two coins, one atop the other, and force them to fuse together, doubling in weight and thickness. Great stacks of coins can then be carried around like rods of orichalum, and with a twist, an arcane caster can pull off individual coins, although not to any size smaller than a single orichalum piece. Being composed of raw arcane force, orichalum coins (whether separate or fused into rods) are indestructible to any force less than a disintegrate spell, although they are vulnerable to targetted dispel magic effects, which cause them to dissipate into arcane force, light and heat, creating non-damaging but noticeable displays of energy.
Other magical coins could include glassteel coins, which would be 'tested' by moneylenders by smacking them hard against a table (a glass coin would shatter, and the person attempting to pass it off as 'wizard's crystal' would be in trouble).
The rarest type of 'coin' recognized by the gnomish moneylenders would be flasks of small red grains, 60 to a flask, that, when sealed in yellow wax and dropped into a small quantity of boiling lead, transform it into gold. 1 lb. of gold (50 pennies worth) is created for each grain, allowing a tiny flask to be transported from one place to another, without anyone realizing that the courier is carrying 3000 gp worth of gold. Since the alchemical process to create these grains requires an equal amount of gold to be boiled down, this does not actually *create* wealth, so much as make it more portable, by transforming pounds of gold to tiny ruddy grains. Some value is lost in the requirement to expend an equal amount of lead at the destination, but it is generally safer, and easier to move vast fortunes via teleportation or animal messenger or similar unusual means, thanks to this technique. Even the *existence* of this technique is very much a gnomish secret, and likely to stay that way, so long as gnomish assassins are on the job....
