The Treasury represents the accumulated financial gain from 
Raw Production, 
Tourism Income and 
Commonwealth Income. It is measured in Credits. The Treasury grows according to the 
Net Weekly Income, which is the Gross Weekly Income minus the 
Maintenance costs of improvements, ships and starbases.
The Treasury is useful in diplomacy, building starbase modules, and rushing improvements and ships, among other things.
Generating 
Gross Weekly Income
There are three additive components of the Gross Weekly Income: GDP, Tourism Income and, with 
installed, Commonwealth Income. The GDP and Tourism Income are taxed according to the Tax Rate to yield their contribution to the Gross Weekly Income.
GDP
The GDP, or Gross Domestic Product, is the sum of the Gross Income of each of the colonies. Assigning a leader to Wealth boosts GDP.
Tourism Income
Tourism provides a safe, steady income that grows with 
Influence.
Commonwealth Income
Commonwealths, introduced in , pay a tribute every week. The Commonwealth Income is the sum of all tribute payments.
Reducing Maintenance
A critical part of creating wealth is to minimize spending. For example, just about everything you build requires maintenance. Hence a colony dedicated to ship building has no use for a research building. Clearly it should be destroyed to save the maintenance (and some useful building substituted). Decommissioning ships that are out of date is also reducing maintenance. On a larger scale, judging the size of fleets required for a given task is an important skill to learn so that one does not "overbuild" and spend maintenance for impressive fleets that actually are not being used.
Other ways to increase the Treasury
- Bartering
- The Galactic Market from
- The Aid Economy and Strip Mine improvements
- Promoting an Entrepreneur to a Mogul in
- Surveying anomalies
- Studying a wealth relic
- Conquering (looting) planets with the Conqueror ability
Ways to spend the Treasury
- Bartering
- The Galactic Market from
- Building starbase modules and asteroid mines
- Rushing improvements and ships
- Hiring mercenaries with
