Galaxy Chess

From the box:

Once in future time ... mankind lives as nomads and astronauts in the universe. They call themselves Terranians and their needs are supplied by huge space shuttles from distant planets and galaxies. They are very wealthy, but not alone in space.

Aliens, extraterrestrial tribes, like the fierce Martians, scouting through the universe, always eagerly search for resources, energy and slaves. So the conflict is due to come....