In my SF RPG setting Flat Black there are about a thousand inhabited worlds, many of which have several independent states ("colonies") on them. And most of the several thousand colonies issue their own currency, though admittedly some are too undeveloped to have currency as such. In the midst of potential monetary chaos there shines one shred of sanity, the existence of an interstellar currency in the shape of the Imperial crown.
Imperial crowns are issued by the Imperial Treasury, and technically they are a fiat currency, valuable only by decree. They are not made of any precious material that might give them an intrinsic value. They are not redeemable in anything else. They aren't even a legal tender for taxes, because there are no Imperial taxes. Basically, Imperial crowns are valuable because you can use them to pay interstellar fares and freight charges, and because you can buy land on frontier planets from Eichberger Realty using them. That naturally makes them so important that they are far the most important reserve currency in Flat Black, and the currency most used in interstellar commerce. Very few other currencies are liquid other than on the planet where they are issued: interstellar payments are settled in crowns; interstellar profits must be repatriated in crowns or in goods.
The value of an Imperial crown varies from place to place. In Imperial Direct Jurisdiction (IDJ) its purchasing power is ForeSight's standard value unit (SVU). That's defined as the price of a decent meal with a drink at an inexpensive and unpretentious eatery, such as McDonald's. I peg the SVU standard as a Big Mac, regular fries, sundae, and regular orange juice. I think that's about A$8.70 now. In the Suite, that fortunate handful of colonies that are at the cutting edge of economic development*, an Imperial crown will exchange for valuta with a purchasing power of 1 SVU. As a rough rule of thumb the real exchange rate doubles for every full ForeSight tech level of difference in development. On the very poorest worlds, where the methods of production are roughly FS TL 1.5 (GURPS TL 1 (mature)), an Imperial crown will exchange for local coins with a purchasing power of about 11.3 SVU. That's more or less a hundred Australian dollars.
Imperial cash is produced in denominations of 0.01, 0.05, 0.2, 1, 5, 20, 100, 500, and 2 000 crowns. The three smallest denominations are coins of some sort, perhaps minted in titanium. The two largest represent huge sums of money: they are rare, and used mostly in settlements between banks and governments. Notes of the Imperial crown are made of a tough laminate with a wide range of features to make forgery difficult. These include a distinctive texture to the touch, distinctive patterns in vivid colours (chosen to challenge the gamut of common printing technologies), micro-printed features visible only with a magnifying glass and with a microscope, distinctive patterns and features of transparent, translucent, and opaque sections, and embedded optical logic that can be interrogated with high-tech fake-meters. The backgrounds of ones are red/maroon, of fives orange/ochre, twenties yellow/mustard, hundreds varied green, five-hundreds blue/indigo, and two-thousands violet/purple. Bills of larger denominations are progressively longer than the smaller bills.
A run-of the mill C-average Imperial officer has a salary of about 9,216 crowns per year at mid-career, and retires with a pension of about 13,000 crowns per year. The salary includes bed, board, uniforms, medical etc., the pension does not, so it practically must be either supplemented with savings or enjoyed with the advantages of superior purchasing power at low development level.
I am in considerable doubt about what glyph to use as a currency symbol to use for Imperial crowns. I want to use the generic currency symbol ¤ for something else. An ideogram of a crown (♔) is cute, but would be slow to draw if anyone wanted to write in, say, their notes or on their character sheet. A cent sign (¢) is type-able on a Mac and has an alt-key combination on a PC clone, but it might cause confusion even if it went before the figures instead of after them. The colón symbol (₡) would be suitable, but is still in use in Costa Rica and is neither type-able nor equipped with an alt-key combination. The cruzeiro (₢) symbol is suitable and no longer in use, but is neither type-able not alt-keyed. A copyright symbol (©, Ⓒ, or ⓒ) is typeable and alt-keyed, ugly and slow to draw, and might produce confusion and gybes. Other possibilities include a script C (not supported by phpbb), blackletter C (not supported by phpbb), double-struck C (ℂ), or, rather arbitrarily, a C-with-cedilla (Ç). Moving on to thoughts of an I-for-Imperial there is blackletter or fraktur I (not supported by phpbb), and perhaps a double-dagger might do ‡. Any suggestions?
* i.e. ForeSight tech level 8.5. Approximately GURPS TL10 (advanced).
— Brett Evill
My SFRPG setting, Flat Black© My posts on SFRPG must not be reproduced beyond the board except with explicit permission from me.