I always try to make fantasy worlds as realistic as possible. I know it sounds stupid, but I believe this is only a prerequisite of completeness. I would vote for the "multiple currencies" or more precisely, the multiple changes of the same money. And yes, gold, silver, and copper are the most obvious choices, mainly because players will adept to such a well-known system quickly. To make it simple, I wouldn't make denominations, and different types of coins (like the € has specific images of it's host countries), because it would take a lot of time. Instead, it should be defined that 1 Unit of Gold = 100 Unit of Silver, and 1 Unit of Silver = 50 Copper. (On the other hand, it would make an exciting new aspect to the game, if the exchange rates would change day-to-day etc... ) But why is it good? 1. Differentiation: Naturally, one can assume that the city core of a capital is wealthier than the slums. As such, it is really irrealistic to use the same object to trade with. Copper should reflect the poor people, so mundane foods, non-magical weapons, clothing, etc should be. 2. Normalization: I also found it really irrealistic, to have 345.674 Gold pieces, because it clearly meant that I possess more money than any other NPC in the game. Not to mention, that such a great amount of gold would be impossible to contain/ carry. In my opinion, it is easier to read: 245 Gold, 124 Silver, 233 Copper. 3. Banking: As other things, this has also been mentioned here. I'm studying economics, that's why I'm really interested in this one. :D But please, imagine the new aspects of this as well. A bank could provide you with a lot of new services: exchange money, "account number" or more precisely, a safe place to hold all your valuables (I can even imagine a "debit card", an arcane stone with runes, that is in direct magical connection wtih the bank, and it can magically teleport the amount of gold, scribed in it with the hands of it's owner), trading with jewellery and precious metals/ gems, buying incredibly expensive and powerful/ unique artifacts, investing (say, you give 2.000 Gold, and you have a chance of winning back more, or less gold in the end of a given period), as well as buying property and estates. If the game is about to contain so much money (like BG), then I can imagine to "buy" Quests. (e.g. you buy a land, an estate, servants, a name or possibly a rank, than you have new responsibilities, and duties, etc...) That would be a possible way to spend your money when you have no other things to buy. P.S.: Sorry for any mistakes or repeated ideas. I just wanted to express my point of view.