In StarCraft II, units are tagged with one or more Attributes that determine bonus damage, affect targeting, and/or can influence spells and abilities; as opposed to in StarCraft, where damage may be reduced depending on what unit type is being damaged. Damage is added on a "per hit" basis, and bonuses are calculated before armor is subtracted.
Attack types are more varied than in StarCraft, and can gain bonuses towards light, armored, biological, and massive units. Most units are either light or armored, which roughly corresponds to non-large and large unit sizes of StarCraft, respectively. Buildings are treated as armored and have the "structure" property. Some units, such as the archon, are neither light nor armored.
Shields are subject to the bonus damage of the unit underneath them.
Units can then have two additional attributes from the following: detector, massive, psionic, structure. In the Campaign, some units are marked by a Heroic attribute; this identifies that the unit is resistant to "control-effects" and/or has significant "plot-armor" within the Campaign story.
↑ 1.01.1Light armor, heavy armor, biological, mechanical, giant, psionic, etc. are some attributes that units can have. For example, the Ultralisk has “heavy armor – biological – giant” attributes, whereas the Archon has the “psionic” attribute. You can probably tell from looking at the Archon, but not all units are divided into [light armor/heavy armor]. Damage calculation is also different from the previous game. Units’ attacks always do at least 100% of the damage value shown on the screen. And then, depending on the attack’s property, additional damage may be dealt when attacking units with specific attributes. For example the Archon’s base damage is 25, and deals an additional 10 damage against biological targets. Therefore, Zerg units (which are usually biological) take 35 damage when attacked by Archons. And in the case of the Siege Tank, its Siege Mode deals 60 damage, so it deals 60 damage to all ground units. If the old system of “explosive, concussive” and “small, medium, large” was used, then Marines would take reduced damage from a Siege Tank. Kicho. 2009-01-14. Starcraft II Production News. StarCraft Legacy. Accessed 2010-01-25.
↑"(10+5-2) x2 = 26
each missile has the bonus and the reduction calculated separately. nice question though ;)"
What he said.
Damage is added up on a per hit basis. Then armor is subtracted from each hit. It doesn't matter how many shots you fire at once, we calculate each hit separately. We have been pretty good so far about making sure that the graphics match the number of hits. So if you see two missiles firing out of a unit, that's going to be two separate hits. Cavez, Kain175. 2009-02-12. Complicated question about bonus damage. Battle.net StarCraft II General Discussion Forum. Accessed 2009-02-12.
↑ 3.03.1At the moment, there is 'light' and 'armored' armor classes. Buildings also fall under the 'armored' armor class.
Attacks on the other hand are a bit more varied. There is bonus damage towards, 'light, armored, biological, and massive.' Knowing a unit's damage bonuses will be very important in knowing what to use to counter certain units. Karune. 2008-09-30. Armor and Weapon type. Battle.net StarCraft II General Discussion Forum. Accessed 2008-09-30.