Master of Orion II: Battle at Antares/Money matters

Especially when you don't have enough, either in the early game or when you're conquering the galaxy.

What happens if you run out of money?
The game software decides which items to scrap in order to raise cash and maintenance costs, and it's seldom what you would have considered the least painful thing to scrap.

How your finances work
Your citizens (but not Androids or Natives) pay tax into your Treasury, and that's the bulk of your income. Note that Non-Lithovores usually have a slight food surplus, and Lithovores may have one if they have colonies with Natives; surpluses are automatically sold at the end of each turn, for 0.5 BC per unit of food.

Various racial / empire traits can increase your income from these sources - or decrease them if you chose -0.5 BC.

Spies can be a severe drain on the finances of a young empire, but usually cease to be a serious drain later. The same is true of using Freighters to move population.

But the greatest financial threats are:
 * Maintenance costs of buildings, usually early in the game when you'd like have Automated Factories at even the smallest colonies. Population growth usually cures that type of problem by increasing the nmber of taxpayers.
 * Having a fleet that requires more command points (CP) than your empire generates. Early in the game you get 5 CP for free and 1 per Starbase, but you seldom have more than a handful of Starbases because they are large construction projects (400 PP). Right through the game each Frigate costs 1 CP, each Destroyer costs 2, each Cruiser costs 3 and each Battleship costs 4. Each Titan ship costs 5 CP if you research and build them, and each Doomstar costs 6 CP if you research and build them. As if that wasn't enough, each Troop Transport costs 1 CP, and you usually want at least 10 to start an invasion campaign while you generally need 20 or more to prevent the campaign from stalling through runnig opout of Transports (Transpirts are not reusable).

Later you can upgrade Starbases to Battlestations, which gnerate 2 command points each, if you research Battlestation

Curbing costs
At low tech and production levels this is much easier than increasing income.

Maintenance costs of buildings
Penalties on some planets.

Income boosters
And when it's worth building them.