Healing (Civ4)

Healing is the process by which damaged units regain their strength.

Hitpoints[]

Damage is tracked using a mechanism called hitpoints (HP); all units have 100 hitpoints. When a unit is damaged, its hitpoints are reduced. A unit at 0 HP is destroyed. Units with between 1 and 99 hitpoints are damaged, and may be eligible to heal.

Healing via Promotions[]

When a unit takes the Heal Instantly promotion it immediately heals half of its total damage. That is, if it is at HP hitpoints, it will end up at:

HP + 0.5 * (100 - HP) hitpoints

Promotion healing is an entirely separate mechanism from normal healing; the rest of this article describes normal healing.

Timing of Healing[]

Healing takes place at the beginning of each civilization's turn. Thus, other civs will have a chance to attack a damaged unit before it can heal. Also, this means that fortified defenders who are attacked but not destroyed by an enemy get to heal in their own turn.

Eligibility for Healing[]

A unit will only heal if it is damaged, and if it is eligible for healing. A unit with the March promotion is always eligible for healing, regardless of what it does during its turn.

For units without March, to be eligible to heal a unit may do very little in its turn. Specifically, performing any of the following actions render a unit ineligible to heal:

being airlifted
attacking in combat
bombarding
bombing/doing an air strike (air units)
loading or unloading (including from ship to ship)
movement (except as a passenger)
pillaging
Re-basing (air units)
recon missions (air units)
being upgraded

The following actions do not affect a unit's eligibility for healing:

defending in combat
fortifying
intercepting (air units)
taking a promotion
being moved as a passenger by a ship
sentry
sleep

Rate of Healing[]

The rate that units heal can vary widely depending on many factors. These are described in this section. Healing rates are always calculated in hitpoints. Note that in a lot of Civ4 documentation you will not see healing rates given in hitpoints, but rather in percentages. Since all units have 100HP, using percentages is a way of describing the rate while hiding the hitpoint mechanism.

A unit's heal rate is determined by adding its base healing rate to, if applicable, any medic healing and Hospital healing.

Base Healing Rate[]

The base healing rate a unit gets varies depending on whether or not it is in a city. In a city, eligible units will heal:

15HP per turn in a city which is in resistance.
20HP per turn in any other city.

Otherwise (that is, not in a city), eligible units heal:

5HP per turn in enemy territory. Units with the Combat V promotion get 15HP per turn instead of 5.
10HP per turn in neutral territory. Units with the Combat IV promotion get 20HP per turn instead of 10.
15HP per turn in home or allied territory.

The terms "enemy", "neutral", and "allied" used above are defined as follows:

An enemy civilization is one that a civilization is at war with; barbarians are included here since they are always at war with all civs. Enemy territory is any tile owned by an enemy civ.
A neutral civilization is any non-enemy. Neutral territory is any tile owned by a neutral civ, and also any tile which is not owned at all (that is, unclaimed by any culture).
An allied civilization of a civilization is either:
- a vassal or suzerain of the civilization
- a civilization that is in a permanent alliance with the civ
- a teammate civilization (teams are defined at game start; usually there is just one civ per team)
The home civilization is the one owning a unit or tile.

Medics[]

Units that have Medic promotions (and also Woodsman III) have a healing effect. Such units are called medics. Medics operate on units based on where they end their move (since healing actually happens at the beginning of the next turn). Note that movement (and the many other things listed above) may make the medic unit itself in ineligible for healing, but it will not affect its ability to heal other units. A medic will heal all eligible units it its range, including itself. Medics of any kind can heal land, air and naval units. Medics will heal the units of an allied civilization.

The hitpoints healing by medics, and their range, are as follows:

Medic I: same tile only, +10HP
Medic II: adjacent tiles only, +10HP
Medic III: same tile and adjacent tiles, +15HP (thus, +25HP total since requires Medic I and II as prereqs)
Woodsman III: same tile only, +15HP

Medics cannot heal units across a land/sea boundary. All units in a port are considered to be on the land side of the land/sea boundary.

No more than one medic can operate on a unit eligible for healing each turn. If multiple medics are in range of a unit, then the one with the best healing rate for that unit will be used.

Hospitals[]

A Hospital does not work in a city during resistance. Otherwise, the Hospital heals all eligible units on its tile +10HP. (Its tile is the city center tile of the city it is built in.) All units includes allied and neutral units.