Since the Arctic Future the limit of two premium expansions per age rises accordingly: Arctic Future unlocks 3, Oceanic Future unlocks 6, Virtual Future unlocks 6, Space Age Mars unlocks 3, Space Age Asteroid Belt unlocks 3 and Space Age Jupiter Moon unlocks 12. If the player advanced through the ages without premium expansions, then those expansions can be bought retrospectively. Premium expansions are, however, limited to two expansions per age, meaning that if player has already placed two premium expansions in the current age the next two premium expansions will become available only once the player advances to the next age. Premium expansions can be bought with diamonds. Medals can be obtained from PVP tower competitions, contribution rewards from Great Buildings, from medal packages during special events, quests, Daily Challenges, Guild Expeditions, incidents and special buildings placed in the city.

Victory expansions do not have to be individually unlocked and can be placed at any time provided the player has enough medals to pay for them. Victory expansions can be bought with medals.

Alternatively, players can pay diamonds instead. Once unlocked, players must pay coins to place the expansion. Reward expansions are unlocked by researching certain technologies in the technology tree or rewarded upon the conquest of certain provinces on the campaign map. Each of those have different means of availability. There are three different types of expansions: Reward expansion, Victory expansion and Diamond expansion.

How to get diamonds forge of empires