Worth to know: * Improvements can be upgraded, changed to another type of improvement, or deconstructed. Super Projects, Galactic Achievements, Trade Goods, Initial Colony and Civilization Capital can't. * Some of the Improvements, Super Projects, and Galactic Achievements are restricted to civilizations with a certain alignment or a technology only available to one specific race. * When taking over a planet from another race, normal improvements are lost if the new owner does not possess the appropriate technologies. All other improvements remain regardless. Invasion plans that result in lost improvements will generally only affect normal improvements as well.