Foreign currencies.

[Bubblegum Knight]

Hey guys. How does one country start trading with another if they have separate currencies? Do they just trade goods instead? Do they adopt a value system for the other currency? Do they just use the foreign currency to buy stuff from the other nation? Or do they develop a new national currency instead? Also, how are foreign merchants treated in other countries?

[waldronate]

Many of these questions might be better suited to a world-building forum ( https://www.reddit.com/r/worldbuilding/ or http://worldbuilding.stackexchange.com/ are two examples, with many others accessible via Internet search for world building and campaign building).