A Unit is a controllable character used in the Quests and PVP matches.
- Units are featured in all civilizations of Age of Empires Online as the most important parts of the them.
- Each unit has his unique abilities and is good against other enemy troops.
- A combination of a few or many troops makes a good army in combat.
- There are three types of units: Economy, Military and Support Units.
- Main article: Units (Celtic)
- Main article: Units (Egyptian)
- Main article: Units (Greek)
- Main article: Units (Persian)
- Main article: Units (Babylonian)
- Main article: Units (Norse)
- Main article: Units (Roman)
- Main article: Unique Units
Economic units are produced in order to enhance the economy, infrastructure, or map accessibility. Economy Units perform jobs such as harvesting Resources, constructing Buildings, or transporting other units.
- Villagers are the primary economic unit for a player. This unit can build structures, collect Food, Wood, Gold, and Stone, and repair buildings and mechanical units.
- Caravans produce gold for the player by making trade routes between the Market and the player/allied Town Center. The greater the distance the unit must travel, the more gold it produces. This however means that the longer it takes for a caravan to travel, the more gold it generates. It is not determined on how long the market and the town centers are.
- Fishing Boats are naval ships that can harvest food from Fish and repair other damaged ships.
- Merchant Transports are naval ships that can make trade routes between two Docks to produce gold and transport land units across water.
Military units are produced purely for killing other units and destroying enemy buildings. There are several categories of units:
- Infantry units form the core of an army. As front-line fighters, they usually have high armor and high damage output. Norse infantry can construct military and defensive buildings. These units are used to tank out because of their cheap cost and large health.
- Ranged units have a ranged attack that allows them to damage other units at a distance. These units are generally vulnerable to melee attacks, and are usually placed at the rear of an army. These units are overall used for massing as they can deal a huge amount of damage at the enemies at once.
- Cavalry units are generally the fastest land units in the game and normally bulkier than other units. Due to their high mobility, cavalry are versatile and can play a variety of roles. These units are overall used to raid the enemies or putting out a on-slaught charge.
- Siege units are slow, expensive units with an exceedingly high damage output. They are especially good against buildings and large, tightly-packed groups of slow moving units. Siege units are very vulnerable to melee combat, so they are usually kept in the back of an army with several melee units defending them. Some of these units can be used to scare the enemies into retreating after suffering heavy casualties from the Catapults. Some of these units can also take in pierce damage, leaving building and ranged defenses useless against them, but however taking melee damage is not.
- Scouts are used for exploring the map. They are fast and have a large Line-of-Sight, they can be used to build Outpost which has a huge line of sight and give the player a huge advantage.
- Warships are used to fight for the control over the oceans. They are more expensive than the other units and are also stronger, these units have powerful damage and can take a beating, but they can only be used in seas or nearby coasts.
Support units have uses that are not always directly related to combat. These units possess powers such as healing, converting enemy units or buildings over to the player's side, or enhancing the powers of a building.
- Priest (Greek) is a Greek Support unit that can heal units in a small area out of battle, as well as convert enemy units.
- Priest (Babylonian) is a Babylonian Support unit that can heal units in a small area out of battle, as well as convert enemy units.
- Priestess of Ra is an Egyptian support unit that can heal units in a small area in and out of battle, as well as empower dropoff buildings to increase resource gathering rates and empower training buildings to increase training, and research speeds.
- Priest of Set is an Egyptian support unit that can heal units in a small area out of battle, as well as cause chaos in enemy units, removing that unit's allegience.
- Priest of Ptah is an Egyptian support unit that can heal units in a small area out of battle, as well as convert enemy units and buildings in an area, they suffer a -20% conversion rate penalty however for the area effect.
- Priest of Amen is a consumeable support unit that can heal units in a small area out of battle, as well as cause chaos in enemy units, removing that unit's allegience. This unit is only accessible via consumable or as a mission unit.
- Magus is a Persian Support unit that can heal units in a small area out of battle as well as convert enemy units.
- Augur is a Celtic Support unit that can sacrifice animals for powerful boosts and convert enemy units.
- Druid is a Celtic Support unit that provides combat support, empowers and heals friendly units. The druid also provides a 10% damage boost to the healing units.
- Seer is a Norse Support unit that can convert enemy units, and can summon Raven: a flying scout unit.
- Rhapsode is a Norse Support unit the heals friendly units out of Combat while also converting units.