|This article is about the armor classes in Age of Empires II which define bonus damage. For the two armor types which define base damage, see armor and pierce armor.|
The bonus attack and armor class system isn't directly displayed in-game. The only visual element of armor classes is noticing the attack value bonuses that units and buildings inflict on each other, but even then, heavy amounts of cross-referencing of the unit and building types taking and receiving damage would have to be tediously studied; and combined with the fact that the type of armor classes assigned to each unit and building are never specified in-game. The only way to directly see armor class bonuses and their values, aside from the information of this wiki, would be the use of a third-party program.
While the tech tree states for each unit against which other unit it deals bonus damage, it doesn't tell the player how this bonus damage is dealt, or which unit is in which armor class. While most armor classes are intuitive (for example, though it's clear that the Eagle Warrior is in the infantry class), there are also many which are not. In another example, the aforementioned Eagle Warrior is also in its own Eagle Warrior class, and Champions deal significant bonus damage against this class. Neither is referenced anywhere in the game. Another example are Camel Riders: They aren't in the cavalry class like one might assume, but instead in their own camel class, which takes less bonus damage than the cavalry class, so they are less vulnerable to their counter units than the game suggests.
Basically, the bonus damage is calculated the same way as the base damage is calculated (simply by subtraction of attack and armor), but in order to calculate bonus damage in the first place, the attacking unit logically has to have an attack bonus against its target. This is where the armor classes come into play.
Simply speaking, bonus damage is a flat additive value to the base damage and if a unit has more than one armor class, the bonus damages of the attacking unit stack. For example, the War Elephant is in the war elephant and in the cavalry armor class, and the Halberdier has an attack bonus against both classes. So both bonus damages are added when a Halberdier attacks a War Elephant.
Each unit has an armor value for every armor class it is assigned to. For most units this armor value is 0 and simply determines that they are in this class and take bonus damage, but for some units, it is non-zero. A positive value indicates that this unit (partially) resists bonus attacks against this armor class, while a negative value means it takes even more damage. For example, the Cataphract has +12 cavalry armor, making it less vulnerable to anti-cavalry attacks than other cavalry. On the other hand, for example, the Ballista Elephant has -2 cavalry armor, making it take even more damage from anti-cavalry attacks.
The attack calculation in Age of Empires II basically works in three steps. Melee damage, pierce damage, and bonus damage are calculated separately. The damage is calculated like this:
How melee (n) and pierce (p) damage work is described here. This page addresses the last part in the calculation concerning the bonus (i) damage. k.elev is the elevation multiplier, which increases the total damage dealt when a unit has high ground (cliffs or higher elevation) and decreases the damage dealt when a unit is standing on a lower elevation.
While the formula may look complicated at first glance, it basically says that a specific armor class armor is subtracted from its respective bonus attack, but the individual result cannot be negative. This resulting value (positive in most cases) is added to the total damage dealt. Bonus attack cannot be reduced by melee or pierce armor.
Unlike with melee and pierce damage, information about the bonus damage cannot be found in the unit infobox.
Every unit that has an attack bonus is given a third (fourth, fifth, ...) attack next to its base pierce and melee attack. And that attack only triggers if the target has a matching armor class.
- An Archer has no melee attack, a pierce attack of 4, and an attack of 3 against the Spearman armor class.
- A Spearman has a melee armor of 0, a pierce armor of 0, and a Spearman armor of 0.
- If the Archer now hits the Spearman, it deals 4-0 (pierce) + 3-0 (Spearman) = 7 damage.
- A Man-at-Arms has a melee armor of 0, a pierce armor of 1, and no Spearman armor.
- If the Archer now hits the Man-at-Arms, it deals 4-1 (pierce) = 3 damage. The bonus damage against Spearmen is not triggered, because the Man-at-Arms does not have the corresponding armor class.
- A Karambit Warrior has a base melee attack of 5, no pierce attack, and an attack of 2 against the Eagle Warrior armor class.
- An Eagle Warrior has a melee armor of 0, a pierce armor of 3, and an Eagle armor of 0.
- If the Karambit Warrior now hits the Eagle Warrior, it deals 5-0 (melee) + 2-0 (Eagle) = 7 damage. The pierce armor does not come into play as the Karambit Warrior does not have a pierce attack.
All three parts in that calculation can be negative if the target has higher armor than the attacking unit has attack. As the formula shows, in that case every part is rounded up to zero, so one weak spot cannot be compensated, and the minimum amount of overall damage dealt is always 1. The example below shows this as well as an attack involving negative armor, both melee and pierce attack, and a multi-shot attack. The calculation follows the patterns mentioned above.
- A Chu Ko Nu fires three arrows with an attack. It has a melee attack of 0 (for all its arrows), a pierce attack of 8 for the first arrow, and pierce attack of 3 for all the other arrows.
- A Battering Ram has a melee armor of -3, and a pierce armor of 180.
- If the Chu Ko Nu now hits a Battering Ram, it deals 0-(-3) (melee) + 8-180 (pierce, rounded up to 0) = 3 damage with the first arrow, and 0-(-3) (melee) + 3-180 (pierce, rounded up to 0) = 3 damage for the other two arrows, resulting in a total damage of 9.
- If the Archer from the first example now hits the Battering Ram, it deals 4-180 (pierce, rounded up to 0) = 0 (rounded up to 1) damage. The melee armor does not come into play as the Archer does not have a melee attack.
These examples also show the difference between having no attack or armor (meaning there is no value assigned) and having 0 attack or armor. No attack or armor means the respective part is not calculated, and 0 attack or armor means that the part is calculated. The difference resulting from this can be quite substantial, as the last example shows.
Base armor is the default value of an armor class which a unit does not have. This is an important attribute to make armor classes function.
For example- A Knight is defined to have armor classes of Base Melee (2), Base Pierce (2), Anti-Leitis (0) and Cavalry (0) and Base Armor 1000. This means that it has armor classes of Infantry (1000), Turtle Ship (1000), War Elephant (1000), and so on. Normally all these attack values are less than 1000; in practice, they are actually less than 100. Substituting these values in the formula for damage calculation by a Post-Imperial Viking Champion we get - Damage = (17 - 2) (base melee) + (5 - 0) (cavalry) + (8 - 1000) (Eagles) + (6 - 1000) (Standard Buildings) + (4 - 1000) (Camels) = 20.
The single highest attacks in the game are those by Furious the Monkey Boy against standard buildings (999) and Secondary Projectiles of Organ Guns (1002).
List of armor classes
- 1 - Infantry
- 2 - Turtle Ships
- 3 - Base pierce
- 4 - Base melee
- 5 - Elephant units
- 8 - Mounted units (except Camel units)
- 14 - Predator animals
- 15 - All Archers and Mamelukes
- 16 - Ships (except Fishing Ships)
- 17 - Rams and unpacked Trebuchets
- 18 - Trees
- 19 - Unique units
- 20 - Siege weapons
- 23 - Gunpowder units
- 24 - Aggressive Huntable Animals
- 25 - Monk units
- 27 - Spearman-line units
- 28 - Mounted archers
- 29 - Eagle units
- 30 - Camel units
- 31 - Standard Melee or Anti-Leitis [no official name] (armor ignoring effect against units)
- 32 - Condottiero
- 33 - Unused
- 34 - Fishing Ships
- 35 - Mamelukes
- 36 - Heroes, Heroines, Queens and King
- 11 - Buildings
- 13 - Stone defense except Castle variations
- 21 - Standard buildings (armor ignoring effect against buildings)
- 22 - Walls and gates
- 26 - Castle variations
- All units which cannot be interacted with like flags, dead units and rubble do not have this property.
- All other units are supposed to have the armor classes 3, 4 and 31.
- The Elephant Archer (War elephant, Cavalry, Archer, Unique unit, and Cavalry archer) and the Conquistador (Cavalry, Archer, Unique unit, Gunpowder unit, and Cavalry archer) have the most armor classes of all units, at 5.
- Special Wolves like the Dire Wolf, Hunting Wolf, and Ornlu the Wolf have base armor zero and no armor class, which makes them take all sorts of bonus damage, all of which stack. Herdables (Cows, Sheep etc.) and Showpiece units (like Butterflies, Hawks and Stormy Dogs) also have base armor zero. All other units have 1000 base armor.
- No unit actually has Armor Class 33, but the secondary projectiles of Organ Guns have a whopping 1002 attack of class 33.
- This means that all units which it targets suffer 2 damage.
- A side effect is that Organ Guns are actually the best units to kill hero wolves and herdables in a single shot. Petards can also do this, but they need to get in contact with them and are also destroyed upon use, whereas Organ Guns can do this from a safety of even 7 tiles away.
- Since the Definitive Edition, armor class values other than Base melee and Base pierce (these two were modifiable before too) can be modified in the Scenario Editor. An important point to remember is that the unit should have an attack or armor of that class existing already. Example: Samurai cannot be given an attack bonus against infantry units, because they do not have even 0 attack. However, using Scenario editor, their attack bonus against unique units can be modified.
- The upgrade lines of Skirmishers, Camel Riders, Mangonels, Rams, the Bombard Cannon and the ship lines of the Fire ship and Galley all deal bonus damage against an armor class they are themselves part of. The civilisation-unique Samurai, Jaguar Warrior, Camel Archer, Genitour, (only Elite) Mameluke, Longboat and Caravel do as well.
- Condottieri are responsible for the creation of 2 armor classes (the most by any unit) - the armor class which gives them an attack bonus against gunpowder units and the armor class which helps them receive attack bonus from anti-infantry units other than gunpowder.
- Mamelukes are not Archer units. They share no upgrades with foot archers. They share the Armor class just for the sake of having a proper trash counter (Skirmishers) for balance reasons.