Unit upgrade
Unit upgrades improve a unit type’s attack and hit points, with new upgrade tiers becoming available as the civilization advances. Common tier names are Veteran for European and Federal American units, Elite for Native American and African units, and Disciplined for Asian units; later Imperial Age tiers use names such as Imperial, Legendary, and Exalted.
Upgrade tiers
Most unit upgrades take 30 seconds, and their costs rise sharply with each Age; the exact cost and affected roster vary by civilization and unit. The bonus is added to the unit’s base statistics. Some later-age units already have stronger base statistics, and some units, including many heroes, upgrade automatically when the player advances.
Research timing
Research upgrades for units that will remain central to the army, weighing their cost against additional units, economy, or artillery. Check the civilization’s actual building and roster: upgrade names, availability, affected unit groups, and costs are not universal.
Age tiers, costs and stacking
Unit upgrades are the standard way to keep an army’s hit points and attack relevant as the match advances. Most unit types receive a new tier with each Age, and the research takes 30 seconds. The upgrade usually adds its percentage to the unit’s base statistics; the bonuses from multiple tiers accumulate rather than multiplying one another. Units first introduced in a later Age may have stronger base values because they did not receive earlier upgrades, so compare complete profiles rather than assuming every unit has the same starting point. The names vary by civilization. European and Federal American units generally become Veteran in the Fortress Age, Guard in the Industrial Age and Imperial in the Imperial Age. African and Native American civilizations use names such as Elite, Champion or Legendary depending on the unit, while Asian civilizations use Disciplined, Honored and Exalted. The normal Fortress tier adds 20% hit points and attack, or 25% for Native American civilizations. The Industrial tier usually adds 30%, bringing the total to +50%; some Native American tiers add 25%. The Imperial tier adds a further 50% to base statistics where that unit has the standard sequence. African age upgrades can affect units in groups rather than requiring a separate research for every individual unit. Costs vary with civilization and unit category. A common European Fortress upgrade costs 200 Wood and 200 Coin; Asian and Native American versions can cost 200 Wood and 100 Coin, and African upgrades can cost 250 of each. Industrial Guard, Champion or Honored costs also vary: Europeans commonly pay 600 Wood and 600 Coin, Chinese 300 of each, and major Native American civilizations 400 Wood and 200 Coin. African Champion upgrades can cost 800 of each. Minor civilization upgrades have their own lower cost and may add 35% at the Industrial tier, for a total of +60%; specific native units can have separate costs. Use the civilization and unit’s own entry for exact figures rather than treating a common cost as universal. Royal Guard and National Guard are stronger alternatives for eligible European and American civilizations. These upgrades add 40% hit points and attack at the Guard tier instead of 30%, for a total +60%, and change the unit’s name. Some Church or Home City cards also alter a unit’s name or upgrade availability. Expansion civilizations do not all use this system, and unique units can have their own named tiers, automatic upgrades, shipments or age-up improvements. A unit’s page should be consulted when it departs from the standard sequence. Plan research around the force you actually have. An upgrade costs resources and uses a building or technology slot for 30 seconds; buying it before producing the relevant unit can delay a needed army. On the other hand, a large surviving group gains a broad benefit from one research, which can be more efficient than replacing units one by one. Check whether a special card changes the effect, whether upgrades are automatic, and whether the unit’s later-age base profile differs. The exact tier names, percentages, costs and eligibility are Age of Empires III rules and differ from upgrade systems in other games in the series.
When research is worth its cost
An upgrade applies to the relevant unit type across the army, so a large surviving group usually receives more value than a small queue of replacements. The 30-second research time is short compared with aging, but its Wood and Coin cost can delay artillery, Home City shipment support or the next production cycle. Check whether the upgrade is automatic, whether it requires a previous tier and whether it changes a unit’s name before placing it in the build order. Some named Royal Guard units receive a 40% Industrial upgrade rather than 30%, while minor civilizations may receive 35%; Asian and African upgrade costs also differ from European prices. Special units can have their own percentages and labels, and some shipments upgrade units without using the ordinary research button. Additive percentage bonuses are applied to base statistics, so compare the total bonus and the unit’s starting numbers when choosing between tiers. A later-age unit with strong base health may not need the same priority as an older unit whose line is about to fall behind.
Age-based improvements to attack and hit points
Unit upgrades improve the attack and hit points of a unit type as the match advances. New upgrade tiers become available in successive Ages, and the documented standard research time is 30 seconds. Costs rise substantially from one tier to the next, approximately tripling in the cited profile, so a player should upgrade the units that will remain central to the army rather than every unit in the roster.
Upgrade before a timing, but preserve production
A unit upgrade can turn an existing army into a stronger force without changing its composition, but research competes with new units, Villagers and age advancement. Begin it when the army can hold its position during the research, and keep enough resources for replacements afterward. Civilization cards, Royal Guard or unique improvements may add separate bonuses; read those effects alongside the standard age upgrade rather than treating them as the same technology.