Gold is an in-game currency in Sid Meier's Civilization used to purchase units and buildings (and enemy units, with the Diplomat). It is also used to maintain buildings - if expenses exceed revenue and there is no gold stored up, buildings will no longer function.
Gold can be produced in a variety of ways:
- As an output of trade produced by cities (gold revenue can further be increased by building Marketplaces and Banks).
- Creating a trade route with a Caravan.
- Selling buildings in cities.
- Demanding tribute from less powerful civilizations (when not under Republic or Democracy) after meeting with another civilization's leader.
You can view your gold revenue in the 'Commerce' tab under Advisors.