I use to use different weights and measures for differing cultures on my worlds. However, it got to be too much like real work. Granted, it does create more realism. But the amount of work involved in keeping up with it all was just too much for my liking.
Since around 1992, I have used only the Standard Metric System. It is the easiest system there is. When I was about 11 years old and started to seriously get into amateur astronomy and astrophysics, I found everything was in metric. Thus, I have learned the metric system so well that I find when someone uses American units, I have to convert to metric just to understand it. The only exceptions to this are a person's height (if in feet-inches) and temperature in Farenheit. Otherwise, give it to me in metric.
In my games, I always give weights and measures in metric. If my players do not understand it, then I use a program called
Master Converter to convert into American units. The one thing I love about Master Converter is that you can add your own categories and units. I find it is the best $15 I ever spent. And once registered, you are registered for all future versions. Can't beat that.
For monies and currencies, I still tend to use differing conversion ratios between cultures. This is mainly due to the reason that one culture may be living in an area where silver is so rare as to be twenty, or more, times more valuable than gold. In one of my worlds, one culture had their main citadel/capital inside a volcanic crater which was the opening. Diamonds were so numerous that they became almost valueless to these peoples. However, they also knew that other peoples found them to be very valuable. Thus, the diamonds did have value for trade.
For my worlds, the empire is usually too lazy (read as "too cheap") to make different sizes and devices. They tend to use the same size planchette and device stampers. Or, they used molds and poured the molten metal. Thus, the coins were always the same size and devices, just different metals.
Of course, even using the same size planchettes/molds mean the different coins will weigh differently. Here is a table I made up for the coins of the Hatharnd Empire showing this fact.
Cut and Paste (from web page)
All coins are molded on planchettes that are 25 millimeters in diameter and 2.25 millimeters thick. Using this, one can easily calculate the weight of each type of coin since all are 1104.47mm
3. That computes to 1.10447cc, and using each metal's density, we can easily get the mass of each coin type. The table below summarizes the weights, rounded to nearest hundredth.
Note: On Onaviu, Electrum is a metallic element,
NOT an alloy of silver and gold.
Coin | | Grams | | Ounces |
Tin | | 8.05 | | 0.28 |
Copper | | 9.90 | | 0.35 |
Bronze | | 9.71 | | 0.34 |
Silver | | 11.60 | | 0.41 |
Electrum | | 17.32 | | 0.61 |
Gold | | 21.30 | | 0.75 |
Platinum | | 23.70 | | 0.84 |
Of course, the above is virtually improbable for any empire with Medieval or prior technology. Not impossible, just highly improbable.
rmfr