Regeneration is the ability for a unit or building to self-heal their hit points without the need of a healer, first introduced in Age of Empires II. Units with regeneration are valuable, since they can be used more effectively later if they can be saved at low hit points. This is especially prominent after pitched battles. Such units will receive even faster healing when stacked with other sources of healing, like those from garrisoning and from healers.
Regeneration is often essential in campaign scenarios where the player cannot build a base and train units, but has to fight their way through with a starting army.
Age of Empires[]
With the release of Return of Rome, heroes gain the ability to regenerate at 30 hit points per minute.
Age of Empires II[]
In Age of Empires II, there are a few units that can regenerate, most notably the Berserk. With the release of The Conquerors, all heroes gain a regeneration ability, making them very valuable in campaign scenarios. Often, heroes are also must-survive units, and the regeneration ability aids the player greatly since they can actually use the heroes in front line battles instead of just having to protect them.
Among regular trainable units, regeneration is a fairly exclusive trait. The Berserk is the only unique unit to have an innate regeneration ability. Berber camel units (Camel Riders and Camel Archers) gain a regeneration ability once Maghrebi Camels is researched.
With the release of Dawn of the Dukes, Polish Villagers became the first generic unit with innate regeneration.
In Dynasties of India, Bengali ships regenerate 15 hit points per minute and the Dravidian unique technology, Medical Corps, gives Elephant units regeneration at a speed of 30 hit points per minute.
Regeneration rates[]
- Heroes and Hero buildings: 30 hit points per minute.
- (Elite) Berserk: 40 hit points per minute.
- Berbers: camel units regenerate 15 hit points per minute (after researching Maghrebi Camels).
- Poles: Villagers regenerate 10/15/20 hit points per minute (in the Feudal/Castle/Imperial Age, respectively).
- Bengalis: ships regenerate 15 hit points per minute.
- Dravidians: Elephant units regenerate 30 hit points per minute (after researching Medical Corps).
- Georgians: mounted units regenerate 5/10/15 hit points per minute in the Feudal/Castle/Imperial Age.
Age of Mythology[]
In general, regeneration is a more expanded feature in Age of Mythology, with several major and minor gods having access to certain regeneration-related features. When a unit has finished regenerating, it will briefly shine a green hue (see gallery).
God bonuses and technologies[]
- Odin enables human soldiers to regenerate 2.0 hit points/second.
- Gaia enables buildings to regenerate 3.0 hit points/second.
- Hephaestus Revenge (Leto) enables Automatons to regenerate 1.0 hit point/second.
- Heroic Renewal (Hyperion) enables heroes to regenerate 2 hit points/second.
- Mythic Rejuvenation (Hekate) enables myth units to regenerate 2.0 hit points/second.
- Acupuncture (Nü Wa) enables Peasants to regenerate 0.5 hit points/second.
- Elixir of Immortality (Chang'e) enables Immortals to regenerate 2.0 hit points/second.
Myth units[]
- Colossus (Hephaestus) can heal themselves by eating gold or trees. The rate is 15.0 in the Extended Edition hit points/second.
- Wadjet (Ptah) regenerates 1.0 hit point per second.
- Troll (Forseti) regenerates hit points equal to the damage it causes.
- Behemoth (Rheia) regenerates 2.0 hit points per second.
- Jiangshi (Zhong Kui) regenerates by fighting, similarly to the Troll. The rate is 1.0 hit point/4 damage dealt, and 1.0 hit point/1 damage dealt with the special attack.
Additionally, all reviveable (except Athena and the Golden Fleece) heroes (Arkantos, Amanra, Zhi, etc.) slowly regenerate, similarly to Age of Empires II, but don't die, unlike in Age of Empires II. Instead, when they reach 1 hit point, they collapse and have to be revived by having friendly units approach them.
Campaigns[]
There are other units and buildings found in the campaigns that demonstrate the ability to regenerate hit points. In the Fall of the Trident campaign, the Living Poseidon Statue from the A Place in My Dreams scenario regenerates hit points at tremendous speed. Only Arkantos in his demi-god form, who also regenerates quickly, can destroy it.
In The New Atlantis campaign, various Titans demonstrate an ability to quickly regenerate as well. These include Prometheus in Betrayal at Sikyos and Kronos and Gaia in War of the Titans. The Tower of Odin is a special Wonder that regenerates at such a high speed that the only way to get rid of it is with the Deconstruction Wonder god power.
Age of Empires III[]
In Age of Empires III, passive idle regeneration is based on a percentage of a given units maximum hit points with a activity lockout in seconds before they can begin regeneration. The activity lockout takes effect if the unit takes any action, including walking, training and building, as well as attacking other units. Simply being attacked does not stop regeneration, meaning with enough maximum hit points a unit can regenerate faster then they are being damaged if they are in stand ground stance and not attacking. The formulae can be found in the civs.xml in the data folder if you unpack the data.bar. With update 29715, an icon for the passive regeneration ability has been added in the ability panel for units that can regenerate.
Heroes (such as Explorers, Daimyo and War Chiefs) remain the most notable units that slowly regenerate at a rate of 0.25% maximum hit points every second, after an activity lockout of 3.5 seconds. SPC units in campaigns instead heal for either 0.5% or 0.65% maximum hit points a second. Similar to Age of Mythology, they collapse once their hit points reaches 1, but unlike in Age of Mythology, their hit points don't stop regenerating when they have collapsed.
Other units notable for being the only non-hero units to regenerate are the Sipahi, which are available to the Ottomans, and the Urumi Swordsman, which are available to the Indians. Urumi Swordsman and their Mansabdar counterpart regenerate at 0.25% maximum hit points per second with a 3.5 activity lockout like hero units, while Sipahi uniquely regenerate 2% maximum hit points a second with a 2 second activity lockout. Minutemen class units degenerate at a constant 2% maximum hit points a second, effectively losing hit points every second until their hit point bar reaches zero. Naval units that idle near docks also regenerate; however, that regeneration is a flat amount and does not scale with maximum hit points. Instead, naval units regenerate 2 hit points a second, increasing to 4 hit points a second with the Advanced Dock card.
These units can regenerate conform to the above-mentioned mechanics:
- Campaign heroes
- Explorer
- Explorer Dog
- Sipahi
- Lazerbear
- War Chiefs
- Skull Knight (since update 23511)
- Monks
- Gurkha and Mansabdar Gurkha (before the Defintive Edition)
- Urumi Swordsman and Mansabdar Urumi (since the Defintive Edition)
- Daimyos
- Shogun Tokugawa
- Corsair Captain
- Bolivar
- Generals
- Battleship
- Ras
- Emir
- Akan Tufohen
- Berber Sultan
- Papal Guard
- Papal Lancer
- Papal Zouave
- Maltese units
- Seminole Sharktooth Bowman with Seminole Invincibles
- Highlander with The Black Watch
- Halberdier with Royal Halberdiers or Gustavian Guards
- Fusilier with Walloon Guards
- San Martín
Age of Empires IV[]
A few units have the ability to passively regenerate hit points in Age of Empires IV. Most notably, the standard Scout unit, which most civilizations have access to from the start of the game, regenerates 1 hit point per 4 seconds when not in combat. The unique scouts of the Mongol and Malian civilizations, the Khan and Warrior Scout respectively, also regenerate hit points, making it the second game after Age of Empires III where all civilizations have access to units with regeneration in standard games. The Khan regenerates 1 hit point per 2 seconds, while the regeneration rate of the Warrior Scout increases with each upgrade, with a rate of 1 hit point per second for the base unit, simply named "Scout", 1.5 hit points per second for the regular and Veteran Warrior Scout, and 2.5 per second for the Elite. This makes the Warrior Scout the unit with the fastest passive regeneration in standard games.
As in previous games, the campaigns in Age of Empires IV feature hero-like characters, called leaders, many of whom can passively regenerate hit points. However, not all leaders regenerate, and the rates are not consistent. The leader-like Jeanne d'Arc hero of the Jeanne d'Arc variant civilization also regenerates, with the rate depending on the unit's level, with 1 hit point per second at Level 1, and an another 0.5 hit points per second with every additional level. The English King, which can be trained at the Abbey of Kings landmark, is another leader-like unit with regeneration, at 2 hit points per second. Finally, the Monarch, which is available to all players in the Dominion game mode, also regenerates at 1 hit point per second.
The Mongols' unique Keshik can also regenerate hit points by attacking units, with 3 hit points restored for every attack performed. This is increased by 1 hit point per attack after researching Steppe Lancers, or by 2 with the improved version. Zhu Xi's Legacy can train Shaolin Monks after constructing the Shaolin Monastery landmark, which regenerate 1 hit point per second when not in combat. Their Temple of the Sun landmark can toggle to the Divine Vitality ability, which allows military units to regenerate 2 hit points per second when not in combat. The Byzantines' Cistern of the First Hill landmark gives (non-siege) military units an active ability which allows them to regenerate 25 hit points per second for 6 seconds. Their Imperial Hippodrome landmark unlocks the Triumph ability, which allows all cavalry units to regenerate 2 hit points per second, for up to 45 seconds.
Certain technologies also allow units to passively regenerate hit points. The French Royal Knights can regenerate 1 hit point per second once Chivalry is researched. The Wandering Town technology allows Rus Battering Rams to regenerate 2 hit points per second while attacking. The Holy Roman Empire and Order of the Dragon's Fire Stations technology allows military ships to regenerate 1 hit point every 2 seconds while out of combat. Researching Improved Yam Network allows Mongol Traders to regenerate one hit point every two seconds while in the Yam Aura, while the Gion Festival technology allows Japanese economic units to regenerate to full health every three minutes. Buildings can also be granted regeneration. Holy Roman Empire and Order of the Dragon buildings, with the exception of Farms and walls, have an active regeneration ability if built within the area of influence of a Town Center. This allows them to repair themselves by 150 hit points per second for 20 seconds. It has a 75 second cooldown which is shared between all buildings within the influence.