also, would the kingdoms have different forms of currency? or is it the same for all
There are some currency differences like the best way I can describe it is that Lucae is like America ( U.S. ) with monotonous-colored bills ( which are a light / greyish blue hue ) that range from 1$, 5$, 10$, 20$, 50$, 100$ bills. The coins in Lucae are valued at 1¢, 5¢, 10¢, 25¢.
Then as for Melantia, the bills there are more colorful with more pigmented hues that range from 5$, 10$, 20$, 50$, 100$ bills. The coin value in Melantia commonly range from 1¢, 5¢, 10¢, 25¢, 1$, 2$ – with obvious inspiration from Canada.
Elysium is a bit different as we’ve taken inspiration from Japan for their currency. Elysium’s more common usage of currency derives from their coins which are valued at 1¢, 5¢, 10¢, 50¢, 1$, 5$, 10$. Then as for their bills, they vary in more of a yellow-gold hue to a silver-gray hue that start their value at 20$, 50$, & 100$.
Then as for the currency value / weight differences between each country it goes as such.
1 MLD ( Melantian Dollar ) = 0.77 LUD ( Lucaen Dollar )
1 MLD = 82.35 ESA ( Elysium Argentum )
so on & so forth. so if you would want to calculate the prices of something in different empire you can use google & use the USD for Lucae, CAD for Melantia, & JPY for Elysium.