Each player takes on the role of one of the major Earth-based empires. The aim of the game is to gain influence over the planets and moons of the Solar System by building factories and digging mines. The game is played over three periods. At the start of each period a number of tiles are drawn randomly and placed on the various planets and moons. Players then take it in turn to perform actions, one at a time. After three rounds the game ends and players score points depending on how much influence they have on each planet/moon, which is measured by the number of factories and mines they have on each one.