Milestones are a feature available for all players regardless of premium status. Player unlocks access to powerful Milestone techs at levels 5, 10, 20, 30 and 40. At each Milestone, the player can choose between two specialized bonuses to improve his effectiveness in all quests (excluding PvP). Milestone Techs can be found in the Technology page at the Capital City's Palace.
Unlike the Tech Tree, Milestone technologies can't be reset.
The Player may choose, when logged into another civilization, one milestone per other civilisation to affect it. This is cumulative : the more civilizations, the more cross-civilization Milestones are available. The global bonus can be switched between any of the selected Milestones belonging to a single civilization.