[robertsconley]

It about the relative value of metal by weight.

For example the Roman had copper as. Bronze coins were used as well.


For example in Late Antiquity we had

1 gold solidus (1/72 lb.)
= 24 silver siliquae
= 180 bronze folle

So the rules on page 67 has 100 coins to the pound. Which is about 4.5 grams.


A Late Roman Gold Solidus was 1/72 of a pound or about 6.3 grams
A TFT gp is worth 72% of a Solidus.

A late Roman Silver Siliqua traded at 24 to one Solidus and weighed 3.4 grams.

So roughly A gram of silver traded at a 13 (12.98) to 1 ratio to a gram of Gold. Not far off from 10 to 1. But not exactly on either.

A bronze follis (contains copper but not pure copper) weighs about 10 grams.

Sixty grams of bronze trades for 1 gram of Gold
4.6 grams of bronze trades for 1 gram of Silver.

So given a TFT GP, SP, and CP are all coins of equal weight. It looks like for the numismatically aware, like myself. The 1:10 ratios between each category and the 1:100 ratio of cp to gp are not outside of the bounds of reason.

The lesson here is that historical coin ratio generally based on weights. There are exception as rulers try to debase their coinage but generally correct itself as confidence is lost. The key ratio are the value of gold to silver, and other metals like bronze and copper. That changed over time.

When trying to use historical coinage versus an RPG coinage system it not enough to use the ratios of gold to silver to copper. You need to take in account the metal weight. With RPG coinage the weight are generally equal between different coin types for ease of gaming.

Historical coins are not. Instead they are minted to get close to some even ratio usable for commerce. Resulting in different coin weights not only for the same type of metal but for different metals as well.

For example during the Augustan period. The ratio was about 8.5 silver grams to 1 gold gram. The weight of the coins were such that 25 Silver denarii was worth 1 Gold Aureus. The copper as traded 400 to 1 gold aureus. By weight it was roughly 388 grams of copper to 1 gram of gold.

My preference is a 20 to 1 silver to gold ratio. Silver pennies weigh 240 (rounded to 250) to a pound. A gold crown is weight one ounce and worth 320 silver pennies. Farthings are not minted and worth 1/4 of a silver piece. Rare coin types include the gold penny word 20 silver pennies. Along with the silver mark, a one pound silver bar worth 240d.

Generally what I do with an RPG like TFT is convert everything to silver and then adjust to my preferred system.