How is the gold "produced"?

[Krum]

Gold cannot be mined. You can get gold in 3 ways:

1. Through taxes - before you discover trade that is the only way. All of the villagers that are not working in the mines bring you gold in form of taxes. For every 100 free villagers you get 5 gold an hour.

2. Through the market - you can sell resources for gold on the market. This option is open even without the trade research. However if you don't have trade 1, the commission will be 50%, after the discovery of 1st level trade the commission drops to 30% and then for every level of trade it will drop with 5%. So get the trade research as soon as possible!

3. Through military action - read the other questions regarding this topic.