Planetary determines what a planet does within your empire. The main way it does this is through theprimary structure. Planets can only export resources produced by their primary structure; if the primary structure generates units or nothing, the planet cannot export anythitng and can only import . Some designations have primary structures that do not produce anything by default; these structures instead grant a special effect, like increasing the tech level of other planets.

Planets are typically manually designated by the player, by pressing the “Designate” button. Designating a planet temporarily reduces efficiency. Planets can only be given designations that are allowed by their current tech level and deposits.