Tanks

Tanks are the strongest general-purpose unit, powerful on both attack and defense. In a battle on your own planet, a tank is worth three and a half troopers. With a finished HeadQuarters it is worth four and a half.

They cost a lot to buy but little to keep. A tank army is expensive to build and cheap to maintain, so over a long game tanks are the most efficient force.

High military morale makes your tanks more effective, so keep it up.

A large tank force can bring down a chemical missile fired from another planet. The more tanks you hold for each region, the more often such a missile fails.

Grow your economy first, and then turn your gold into tanks for a force that wins both attacks and defenses.