Gold and economy

What gold is for

Gold pays for your buildings, your warships and your weapons. It comes in continuously, and faster with the right buildings.

Base income from your territory.
Trade ships: a port sends trade ships to other countries' ports; each trip earns gold for both sides. Trade stops for 5 minutes with anyone you fight, and you can stop or restart it with a player.
Trains: a factory lays railways to your nearby cities, ports and factories, and to your allies'. Trains run along them and earn gold at each stop, more at a neighbour's.
Map objectives: +15% gold per objective held (see Expansion).
Conquest: eliminating a player gives you their gold (half for a human, all for a tribe or a nation).
Warships: they capture enemy trade ships.
Donations: your allies can send you gold.
Capital (Nations mode): +10% gold. See Nations mode.

Prices rise with each one you own. Starting prices are in Buildings and Units. A few landmarks:

Cities, ports and factories: 125,000, then 250,000, 500,000, then 1,000,000 maximum each.
Upgrading a building costs the current price of a new building of that type.
Nuclear weapons cost from 750,000 to 25 million and more.

In long games, the final phase raises every player's gold income by the same amount: see End of the game.