Population, also known as the population cap, is a limit to the total number of units a player can field on the map. It is normally determined by the number of Town Centers and Houses that have been built. In most Age of Empires titles, the population cap can be adjusted in the settings tab of each game set up.
In Age of Empires and Age of Empires II, players can go over the population cap by converting units.
Age of Empires
Age of Empires II
In Age of Empires II: The Age of Kings, the maximum population cap is 200. In The Forgotten, however, the population cap can be set up to 500. The Goths can gain +10 population in the Imperial Age due to their civilization bonus.
Buildings providing population room to all civilizations:
- House (5 for all civilizations, 10 for the Incas)
- Town Center (5 for all civilizations, 10 for the Chinese)
- Castle (20)
Buildings providing additional population room to the Slavs and their allies:
If any of these buildings is destroyed, the provided population room is lost, with the exception of the Mongols, who retain the population room (just of Houses, though) once Nomads is researched. The Huns start games with their population cap at the maximum without the need to build Houses.
Age of Mythology
In Age of Mythology, the maximum population cap is 300. However, the player may not always be able to reach the maximum population cap, as the player will need enough Settlements to do so. Most of the time, the population limit will depend on how many Settlements the player has captured. In campaigns and standard games (where there are only few players), it is not possible to meet the maximum population cap of 300, as there is a limited number of Settlements.
In similar fashion to Age of Empires III, military, mythical, and naval units also take up greater amounts of population space. Typically, economic units such as Fishing Ships and villagers (except Atlantean Citizens) take one population slot. Most foot military units (such as infantry or archers) take two population slots. Most mounted units such as cavalry take 3. Siege weapons also take 3 to 5 population slots. Atlantean Citizens take slots. Atlantean units converted to heroes take an additional population slot. Myth unit population slots ranges from 2 to 5. Titans take 20 population slots.
It is possible to exceed the population limit by gaining neutral units or Gaia units in campaign scenarios and custom scenarios. Another instance on where the player can exceed the population limit is in the campaign — when a campaign hero faints, then the player reaches the population limit by creating regular units; after the player manages to revive the said hero, the population limit would be exceeded. The same concept applies to Automata — when the player has reached the population limit, then some of the player's fallen Automata have been fully repaired, the population limit is also exceeded. Upgrading Atlantean units to heroes can also be done over the population limit.
Unit conversion, however, will not be possible if there is not enough free population to house the intended unit. Instead, the Priest will just keep converting the target until enough population has been vacated (i.e. when the player loses some units).
The following buildings provide population:
- Town Center (15, 20 for Fortified Town Center; 18, 23 for Isis)
- Citadel (25, 30 for Fortified Citadel) (Sekhmet only) (28, 33 for Isis, Sudden Death game mode only. )
- House (10)
- Manor (20) (Atlanteans only)
- Garden (1) (Nü Wa only)
The Atlanteans can build a maximum of 5 Manors, while other cultures can build a maximum of 10 Houses, which will equivalent to 100 population slots. Assuming the player has the starting Town Center (without the Fortified Town Center upgrade), the initial population limit should be 115. The population limit can be increased by capturing more Settlements, until enough has been built to reach the game population limit of 300.
Age of Empires III
In Age of Empires III, the population cap is 200. The Chinese civilization's population cap is 220 and the Iroquois can reach 225 (if a maximum amount of Villagers perform the population dance in the Fire Pit). The Sioux start games with their population cap already at the maximum.
Unlike its predecessors Age of Empires I and II, powerful units, such as most cavalry, Mercenaries, and artillery, take up more population slots. Ships and native (Trading Post) units have their own separate population cap, with the exception of Fishing Ships and native Villagers. In contrast to previous titles, multiple selected units are represented by a single unit icon (with number indicator) on the interface.