Damage in StarCraft is applied using basic mathematical equations. It begins with whether the attack hit or missed, if it does hit, the engine calculates the damage as follows: how much damage the attacking unit does, subtracts the armor of the receiving unit, then multiplies by the size vs. damage type modifier. The only exception to the final rule is Shields. Shields instead take full damage from all sources, regardless of the unit's size or damage type modifiers but damage is still reduced by shield armor.
Types of Damage
- See also: Unit Statistics for specific damage types and unit sizes.
There are five damage types in StarCraft:
All damage types deal 100% damage to shields and Defensive Matrix (?).
This damage type deals 100% to small units, 50% damage to medium units, and 25% damage to large units. Units with this damage type are ideal for focus firing on small units to take them out quickly. For instance, a group of Vultures will likely be able to pick off a High Templar before the opponent has time to react. However, that same group of Vultures will be virtually ineffective at killing an Ultralisk.
Units dealing explosive damage deal 100% to large units, 75% to medium units, and 50% to small units. While units dealing this damage type are not ideal at attacking small units, the damage modifier vs. the unit size is not as perverse when compared to concussive damage. Several units that deal explosive damage also deal splash damage, mitigating the damage modifier against small units even further.
Normal Damage is the most common type of damage in the game. It encompasses all first tier infantry units (Marine, Zealot, Zergling), all contact units, all worker units (Drone, Probe, SCV), all air to ground attacks and many other units as well.
Units whose damage is type Normal will deal 100% damage to all units (minus armor, of course). These units often have a weakness other than their attack that can be exploited, for instance Marines have low hit points, so they are killed quickly, and low damage, so armor can stop them. Lurkers deal a high amount of damage, but are immobile while attacking. Guardians are slow and can only attack ground units.
Ability damage comes from units that have a cast-able ability, such as a Science Vessel's Irradiate ability, a High Templar's Psionic Storm, or a Defiler's Plague.
Abilities that deal damage do 100% damage to its target, and ignores armor, provided that the ability can deal damage to the target. For instance, Irradiate may be cast on a mechanical unit such as a Siege Tank, but the ability only deals damage to biological units. Psionic Storm may be cast anywhere on the map, but does not deal damage to buildings.
Special damage is only used by one unit in StarCraft: the Devourer.
The Devourer is the only unit in the game that attacks one unit and does a splash ability (as opposed to splash damage) to the surrounding units. The damage type of the targeted unit is type explosive, and then the stack-able debuff Acid Spores will affect air units within the area that the attack landed.
Multiple Hit Attacks
Certain units deal damage in multiple hits during one attack animation. For example, the Zealots attack, which in total does a base of 16 points of damage, consists of two hits consisting of 8 damage each. It means that if the Zealot attacks a unit with Armor, the Armor bonus will be calculated twice. This is especially noticeable in Zealot versus Ultralisk battles, where Ultralisks benefit greatly from their Chitinous Plating. In rare cases the Zealots can deal only 8 damage, when they are killed before doing the second hit (the hand animation is not shown).
The following is a list of units that do multiple attacks per attack animation:
- Firebat - 2 hits, sometimes 3 hits against medium or large units.
- Zealot - 2 hits
- Goliath (air attack) - 2 hits
- Scout (air attack) - 2 hits
Only ranged attacks have a hit or miss detection. Melee units will always hit their target when attacking. There are four cases in which a miss can occur by a ranged attacker:
- The target is underneath certain doodads which block a percentage of attacks. (Trees, signs, etc.)
- The attacking unit is on low ground while the targeted unit is on high ground.
- The attacking unit is attempting to attack a target underneath a Dark Swarm cloud.
- With any ranged attack, there is a very slight chance of an "air shot" or miss for no apparent reason. It is likely programmed into the game.
Units attempting to attack a target in the first two cases have a 53.125% chance to hit their target. The miss chance in those cases has been frequently but mistakenly reported to be 30% by several sources. Units attempting to attack a target under Dark Swarm have a 0% chance to hit their target until they move out from under the cloud or the cloud wears off. The chance of an "air shot" is 1/256; that is, with the two units on equal elevation, a ranged unit's chance to hit is 99.609375%.
Splash damage is the extra damage dealt to units that are not the primary target of an attack. There are two major types of splash damage; radial splash, and line splash. Splash damage can be indiscriminate - damaging all units in its range - or it can target hostile units only. Unfortunately, allied players' units are considered hostile for splash damage that does not hurt your own units. Splash damage - but not Mutalisk's multidamage - also damage undetected invisible units inside splash radius.
Radial splash deals damage in a circular area with the primary target being the epicenter. Radial splash generally have drop-off points where the splash damage dealt drops from 100% to 50% and 50% to 25%. Examples of units that deal radial splash damage include:
- Siege Tanks in siege mode
- Spider Mines
- Nuclear Missiles
- Reaver Scarabs
- Infested Terrans
Line splash deals full damage to all targets in a straight line. Units that deal line splash include:
- Firebats have two line splash and a radial splash as well. See the Firebat page for more details.
- Lurkers will do full damage to all units in the line except your own.
Other Types of Splash
- Mutalisk glaives will bounce from one unit to the next.
HP Regeneration, Repair, and Healing
All three races of StarCraft have the ability to regain hit points on their units and buildings that have sustained damage.
The Terran race has the ability to repair any mechanical units and buildings, including those that are flying, with SCVs. Biological units can be healed by Medics.
- The Health Points of units are counted up to 0.5 (half of a point) of damage.
- Units can slowly damage units which have more armor than their attacks. For example if a unit with 10 points of armor, is attacked by a Marine, who deals 6 damage, it will be still slowly losing life - every two hits, its life will be reduced by 1 point. This is especially noticeable in Marine versus Ultralisk battles.
- If a Terran building loses 2/3 of its HP, it will be considered burning, and the remaining hit points when the building is selected will turn red. When this happens, the building will continue to sustain damage until it destroys itself or is repaired beyond the 1/3 threshold.
- SCVs count as both biological and mechanical. They can be healed by medics and repaired by SCVs (repairing, however, does cost resources).
- In a team game, Medics will heal all ground biological units within range that are your own as well as your allies'.
All Zerg units and buildings, once they have sustained damage, will regenerate over time, until they have reached 100% health again. All Zerg ground units can also be healed by medics (in the case of a Terran ally).
All Protoss units and buildings have shields that will regenerate over time. If damage is sustained beyond the shields of the unit or building, the damage is permanent until the end of the match, or it is killed/destroyed. Biological Protoss units (such as the Zealot and High Templar) can also be healed by medics (allied or mind-controlled).
Hero units, such as Fenix in his Zealot and Dragoon form, as well as Raynor in Hyperion Battlecruiser seem to attack faster than the standard units. In addition, Tassadar, has a "Psi assault" attack dealing 20 normal damage.
In the StarCraft beta, Mutalisks attacked by means of a 'cloud' attack, with animation similar to the one currently used by Devourers. These attack dealt a form of splash damage (just like the one of Devourers, but Blizzard designers decided that the Glave Wurm attacks (which in the StarCraft Beta were used by Queens) fit better.
Defilers also had a form of attack, but it was removed from the final version of the game.