Unit upgrades increase the attack and hit points (HP) of a unit type. A new upgrade becomes available in every Age. All unit upgrades take 30 seconds to complete. The cost approximately triples every Age.
In contrast to the previous installments of series, the unit upgrades of every civilization in Age of Empires III usually do not change the original name of the unit, and in most of the cases only add a title word. Royal Guard upgrades are the most common way of changing the units name, although certain improved Church cards also have this effect. Royal Guard upgrades only apply to European civilizations and the United States, and were not given to other expansion civilizations.
The upgrade effect is always applied to the base units stats, combining additively. Some of the units available in later ages have better base stats because they don't get the early upgrades. This has the effect that their later upgrades are more powerful in comparison.
The Fortress Age upgrade, titled Veteran for European civilizations, Elite for Native American civilizations, and Disciplined for Asian civilizations, adds 20% (25% for Native American civilizations) hit points and attack to the units.
The Industrial Age upgrade, titled Guard for European civilizations, Champion for Native American civilizations, and Honored for Asian civilizations, adds 30% (25% for Native American civilizations) hit points and attack to the units, for a total of +50% hit points and attack.
Guard/Champion/Honored upgrades cost 600 wood and 600 coin for European civilizations, Indian and Japanese; 300 wood and 300 coin for the Chinese; and 400 wood and 200 coin for major Native American civilizations. This includes the Ram and Mantlet for the Iroquois.
Some European civilizations' and United States' Industrial Age unit upgrades carry the title Royal Guard, which adds 40% hit points and attack to the units instead of 30%, for a total of +60% hit points and attack, and changes their name. This makes a civilization's Royal Guard units stronger than other civilizations' Guard units.
Hussar (King's Life Guard)
|Skirmisher (Needle Gunner)|
Grenadier (Humbaraci Corps)
|Crossbowman (Ordinance Besteiro)|
|Cavalry Archer (Tartar)|
|State Militia (Volunteer)|
These upgrades are available to the cannon units unlocked in the same Age from the Artillery Foundry as well as the Siege Workshop (although the cost of the Light Cannon's upgrade requires food and coin in the same amount, instead of food and wood). However these upgrades do not apply to Factory-produced artillery.
The Imperial Age upgrade, titled Imperial for European civilizations, Legendary for Native American civilizations, and Exalted for Asian civilizations, adds 50% hit points and attack to the units, for a total of +100% hit points and attack (+110% in case of Royal Guard units and +75% in case of artillery). This upgrade is also available for the Frigate, Monitor, and Factory-produced artillery, where it is the first upgrade available.
Imperial/Legendary/Exalted upgrades cost 1,500 wood and 1,500 coin for European civilizations, Indians and Japanese. For the Chinese it costs 750 wood and 750 coin per unit. For Asian civilizations, Exalted artillery upgrades cost 1,000 wood and 1,000 coin.
|Age||European||Minor native||Major native||Asian||Chinese|
Some units in Age of Empires III upgrade automatically when reaching a new Age instead of the upgrade having to be bought and researched. These units are usually those not trained in the normal way such as the Explorer, or units mainly available at the Home City.
The following units have this trait:
- Explorer Dog
- War Dog
- War Chief
- Skull Knight
- Dog Soldier
- Flying Crow
- Shogun Tokugawa