One of the more effective colony tools, the Fortress Colony tool doubles the size of a colony in both building and turret hotspots. Fortress Colonies suffer a reduction in spice production but make up for it with their ability to completely prevent raids into their home star system by any enemies besides 4- or 5-star empires and the Grox. It can also field a Strike Fleet. If all the colonies on a planet are upgraded to Fortress Colony status then no attacks by any empire can be made into the star system. Space platforms appear in orbit around the planet. The planet can support a Heavy Fleet.