Each unit variant possesses certain and/or unique abilities, offering a specific function and role in gameplay. The four main types of unit are: economic, military, hero, and animal. In the spin-off Age of Mythology, mythical units are introduced.
Most units can move, which sets them apart from buildings, the other critical entity to feature in all titles of the series.
Age of Empires Edit
- Main article: Units (Age of Empires)
In Age of Empires, units display a white square outline upon selection. All types of unit possess distinct voices, although there is no visual distinction regardless of the civilization the unit is in. Each civilization has access to more or fewer upgrades for a particular unit, and all civilizations have unique bonuses. For example, the Greek's Hoplites move much faster than other civilizations. If no victory conditions are set, players must kill every last enemy unit to win.
Age of Empires II Edit
- Main article: Units (Age of Empires II)
In Age of Empires II, units from different civilizations have distinct voices. Units that have been selected display a white circle beneath its feet, proportionate to the units' size. Every type has a different voice, for example, military units have a different voice from civilians. Every civilization has access to one or two unique units, and some civilizations have restricted access to a certain unit's upgrades, for example, Huns cannot build Fast Fire Ships. In order to defeat an enemy in a conquest-type game, all units must be killed.
Age of Mythology Edit
- Main article: Units (Age of Mythology)
In Age of Mythology, each civilization has completely unique sets of units which have one or more types and generally fall into similar categories or roles. Unit types include workers, human soldiers, siege weapons, naval units, heroes and myth units. Human units are also referred to as mortal units.
Age of Empires III Edit
- Main article: Units (Age of Empires III)
In Age of Empires III, every unit has a unique voice and units of different civilizations have distinct voices. Each civilization has access to a different set of the standard units, for example, the British lack the Skirmisher, but the Germans lack the Musketeer. Military units are now categorized into three groups: Archaic, Standard, and Royal Guard. Archaic units such as the Crossbowman and Pikeman usually can only be upgraded to Veteran status. Standard units can be upgraded to Veteran, then Guard, then Imperial.
Royal Guard units do not have a Guard or Imperial upgrade. Instead they have unique unit upgrades which make the units more powerful than ordinary Guard or Imperial equivalent units. Along with Royal Guard units, civilizations also have a number of unique units, often recruited with the standard set of units.
When scrolled over or selected, units display a circle outline shaded in the player's selected color. Heroes and Mercenaries display a five-pointed star circle, while Consulate units display a unique decorative pattern. Units under the aura of a leader such as the War Chief or the Daimyo will also indicate a different pattern. Unless an enemy player surrenders, all enemy units, including ships and Settlers, must be killed to win the game.
(Note: In the second level of the Act I: Blood campaign, one of the three starting Swiss Pikemen, always has a star and circle underneath it, regardless of selection.)