Armor class (Age of Empires II)

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.

Armor classes are semi-hidden unit attributes in Age of Empires II. They are necessary to make attack bonuses work correctly.

Overview

In-game references

The infobox shows no information about bonus damage dealt or taken.

The bonus attack and armor class system is not 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 is with the use of the Genie Editor, which is the official program to view and edit dataset included in game files.

While the technology tree states which unit is strong against which type of unit, it does not tell if it is by design or by bonus damage. If by bonus damage, it does not 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, it is clear that the Eagle Warrior is in Armor class: Infantry), there are also many which are not. In another example, the aforementioned Eagle Warrior is also in its own Armor class: Eagle Warrior, and Champions deal significant bonus damage against this class. Neither is referenced anywhere in the game. Another example are Camel Riders: they are not in Armor class: Cavalry like one might assume, but instead in their own Armor class: Camel, which takes less bonus damage than the cavalry class from anti-cavalry units, so they are less vulnerable to their counter units than the game suggests.

Attack bonuses come in play due to two independent factors: Armor classes and hill/cliff bonuses. While focusing on Armor classes on this page, the role of hill/cliff bonuses will also be touched on.

Function

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 Armor class: War elephant and in Armor class: Cavalry, 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 is more vulnerable. For example, the Cataphract has +12 cavalry armor, making it less vulnerable to anti-cavalry attacks than other cavalry units. On the other hand, for example, the Elephant Archer has –4 cavalry archer armor, making it take even more damage from anti-cavalry archer attacks.

Damage calculation

The damage in Age of Empires II works in many steps, which is seen as following:

Step 1: Attack multipliers are applied and stored. $Attack_{i} := Attack_{i}\times x$ where $x \geq 1$ is the multiplier on respective attack class i. Attacks are stored as integers only. So an attack value which is not an integer is rounded off. An example where $x \neq 1$ is with the Burgundian gunpowder bonus, where x = 1.25 for all i, and Siege Engineers, where x = 1.2 for i = 11. While x can be less than 1, there exists no reason to do so.

Step 2: Damage due to every class. This step is done for all armor classes present. For any specific armor class i:

$Damage1_{i} = max (min(0, Attack_{i}), Attack_{i} - Armor_{i})$: $Damage1_{i}$ can only be negative if $Attack_{i}$ is negative and can never be lower than $Attack_{i}$.

Step 3: Bonus damage resist multiplier. $Damage2_{i} = Damage1_{i} \times (1-x)$ for enemy units, where x is the value of the attribute. Usually x = 0. This does not apply for i = 3, 4, 31, 33 since these classes provide base damage. Currently this property is used by Sicilian infantry, cavalry, and archers, where x = 0.33, and by Bengali elephants and Persian Castles with Citadels, where x = 0.25. Note that the $Damage2_{i}$ values may not be integers and are not stored, so they are allowed to have decimal values.

Step 4: Addition. $Damage3 = \Sigma_i Damage2_{i}$for all i, where $\Sigma_i$ denotes summation over all armor classes.

Step 5: Other bonus multipliers. Unlike the previous multiplier, this does apply for i = 3, 4, 31, 33. $Damage4 = x \times Damage3$where x is calculated as follows, starting at x = 1:

• This sub-step does not apply to secondary projectiles. If the unit dealing damage is on high ground or above the cliff, $x := x \times 1.25$ or $x := x \times 1.5$ (the latter only for Tatars). If the unit dealing damage is on low ground, $x := x \times 0.75$ or $x := x \times 0.6$ (the latter only for Georgian targets). If the unit receiving damage is a building and on a desert cracked terrain, $x := x \times 1.2$.
• This sub-step does not apply to Chakram Throwers, Arambai, units with blast damage, or secondary projectiles of Hussite Wagons and Organ Guns. If the unit receiving damage was not the intended target (i.e., it is a mishit), $x := x \times 0.5$.
• This sub-step applied only to units with blast damage. x is set according to the type of blast damage. Except for the tapering effect, the main target always receives 100% damage.

Step 6 - Result: $Damage = max(1, Damage4)$ This is to ensure that even if Damage4 < 1, the unit must receive a minimum of 1 damage since it is being attacked. Note that the minimum damage rule is applied after all the attack multipliers.

• Damage may not be an integer, but the game works with the values just fine. It does subtract fractional hit points, but the UI shows only the integer part of the remaining hit points. The unit dies when the remaining hit points reach below 1 (not less than or equal to 0), that is HP<1.

• If the secondary projectile has no respective attack classes applied to it at all (e.g., Mangonel which have no attack classes at all or Longboats have only anti-ship, anti-camel and anti-fishing ship attacks) hits unintended target or if attack ground is used, no damage by such projectile is inflicted. If the secondary hits an intended target, however, it deals the minimum damage of 1 instead.

You might think why values 3, 4, 31, and 33 are excluded from step 3. Step 3 is for reducing bonus damage. These armor classes are dealing regular/base damage by their definition. These are namely base pierce (3), base melee (4), special melee (31), and special pierce (33).

While the formulas may look complicated at first glance, it basically says that a specific armor class value is subtracted from its respective attack class value, but the individual result cannot be negative. Hill and other bonus multipliers are applied. This resulting value is added to the total damage dealt. Bonus attack cannot be reduced by melee or pierce value. Unlike with melee and pierce damage, information about the bonus damage cannot be found in the unit infobox or in tech tree in-game.

Steps 4 and 5 can be interchanged mathematically because the order of operations does not matter there, but it is more time efficient to perform step 4 before step 5.

Also there is no case where an attack class has both an additive boost as well as a multiplier. We can formulate theoretical situations like Bohemians Halberdiers with Chieftains, and Bloodlines and percentage HP boost with Mongols, but the results are consistent because of how these bonuses are implemented. The Bohemian bonus applies before the start of the game (fixed) and Chieftains being a unique technology, needs at least 1 second to finish (variable). Bloodlines applies when we research it (variable), but the Mongol bonus specifically applies to Light Cavalry and upgrades at the start of the game (fixed). When we have either boost fixed, we get consistent results.

List of armor classes

Unit classes

Armor class	Official Name	Notes	Proper Name
1	Infantry	does not include foot archers
2	Turtle Ship	includes Thirisadai	Heavy warship
3	Base pierce	unaffected by bonus damage reductions
4	Base melee	unaffected by bonus damage reductions
5	War elephants	includes all elephant units	Elephant
8	Cavalry	includes Cavalry Archers, Missionaries but specifically excludes Camels	Non-camel mounted unit
15	Archer	includes variations, Skirmishers, Hand Cannoneers, Janissaries and similar mounted units	Archer
16	Ships & Saboteur	specifically excludes Fishing Ships	Ship except Fishing Ship
17	Rams & Trebuchets & Siege Towers	packed Trebuchets do not have this armor class; includes Armored Elephant line too	High pierce armor siege unit
19	Unique units (except Turtle Ship)	despite its name, it includes Turtle Ships	Unique unit
20	Siege weapon	can also be called siege unit
23	Gunpowder units	includes Bombard Towers
25	Monk	includes Missionaries and Monks with relics
27	Spearman
28	Cavalry archer	includes variations and Conquistadors, Arambai, Genitours	Mounted archer
29	Eagle Warrior
30	Camel	can also be called "camel unit"
31	Leitis Attack	previously used by the Leitis to make its armor ignoring attack work, currently unused; despite the Leitis having a new mechanic, the old armor values were left as it is	Obsolete
32	Condottiero
33		no unit has this armor class, hence any unused armor class can be used; see Trivia
34	Fishing Ship
35	Mameluke
36	Hero	includes Queens and Kings - currently unused except by Ninja
37		belongs to Hussite Wagons and Ballista Elephants	Heavy siege
38		belongs to Skirmishers and Genitours	Skirmisher
39		used for Royal Heirs	Mounted units' attack class

Building classes

Armor class	Official Name	Notes	Proper Name
0		belongs to Wonders and similar buildings - currently unused	Wonders
11	All Buildings (except Port)	there is no such building as Port; Fish Traps are excluded	All Buildings except Fish Traps
13	Stone Walls & Gates & Towers	includes Harbors
21	Standard Buildings	value is always 0 by definition; excludes Fish Traps and Wonders	Standard Buildings except Fish Traps and Wonders
22	Walls & Gates	applies to both stone and palisade structures
26	Castle	includes Kreposts	Castles and Kreposts

Gaia classes

Armor class	Official Name	Notes	Proper Name
14	Predator Animals	consists of Wolves, Lions, Komodo Dragons, Tigers, etc	Wolves
18	Trees	no unit has this armor class, hence any unused armor class can be used
24	Hunted Predator Animals	consists of Wild Boars, Javelina, Elephants and Rhinoceroses	Boars

Base armor

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 10,000. This means that it has armor classes of Infantry (10,000), Turtle Ship (10,000), War Elephant (10,000), and so on. Normally all these attack values are less than 10,000.

Substitute these values in the formula for damage calculation by a Post-Imperial Viking Champion to get:

Damage = (17 - 2 {melee}) + (5 - 0 {cavalry}) + (8 - 10,000 {Eagles}) + (6 - 10,000 {Standard Buildings}) + (4 - 10,000 {Camels}) = 20.

The single highest attacks in the game are those by Secondary Projectiles of Organ Guns and Hussite Wagons (10,002)* and Furious the Monkey Boy against standard buildings (999).

Common values

• Attack class 21 is defined by the game to be a variation of anti-building attack (attack class 11).
  • For buildings (except Fish Traps, Wonders, and Mosques), $armor \, value \, 21 = 0$ always, because it was never meant to be reduced.
  • For reasons unknown, Fish Traps do not have building armor classes (neither 11 nor 21), unlike their counterpart - Farms.
  • For scenario design purposes, Mosques have no armor classes, so they receive 1 damage from every unit other than secondary projectiles of Hussite Wagons and Organ Guns (check Trivia).
  • For reasons unknown, Wonders do not have armor class 21, despite having armor class 11, and have a special armor class 0.
• All units with attack class 1 (other than Hand Cannoneers) have attack class 32, defined as $attack \, value \, 32 = \min(10, attack \, value \, 1)$. This is because Condottieri were made to resist attack bonus of Hand Cannoneers, which is 10, but receive attack bonus from other anti-infantry sources. If the value was less than 10, it was negated entirely, otherwise it was reduced by 10.
• All units except Fire Galleys have exactly same attack vs Fishing Ships (armor class 34), as they have against regular Ships (armor class 16). This was done to promote use of Galleys in Feudal Age to snipe Fishing Ships, rather than the Fire Galley countering everything.
• For the Mangonel and Bombard Cannon lines, $attack \, value \, 37 = attack \, value \, 4$, so that they counter Hussite Wagons and Ballista Elephants more effectively. There is no proper reason, except for the choice of developers to use the same value.
• $Base \, armor = 10,000 = armor \, value \, 33$ for most units and buildings (please check Trivia).
• All units except Halberdier with attack class 8, have attack class 35, defined as $attack \, value \, 35 = attack \, value \, 8 - 11$. For the Halberdier, it is $attack \, value \, 35 = attack \, value \, 8 - 21$. This was done to reduce the amount of damage the Halberdier dealt to Mamelukes without affecting either unit outside of this matchup.

Implications

• Percentage attack upgrades like Burgundian Gunpowder bonus, Bohemian Spearman-line bonus, Siege Engineers, and Heated Shot are calculated and stored in unit stats and are always an integer. The modified values are used to determine damage. Depending on the unit, it may be greater than or less than the percentage increase. Hill bonuses are always calculated in every situation after calculating the damage from armor classes and the damage dealt maybe a non-integer, in which case the shown HP is rounded down.
  • Bohemian Pikemen should get +27.5 vs Cavalry, they actually get +28.
  • A regular Pikeman on a hill also gets +25% damage bonus. Ignoring the insignificant melee attack vs Cavalry, it should deal +27.5 vs Cavalry. It appears in game that it deals +28 in odd hit and +27 in even hit. Behind the scenes, it actually is dealing +27.5 but the new HP of the receiving unit is always rounded down. Extending this rule, on a hypothetical unit having 5 attack vs itself, it will deal 7, 6, 6, and 6 damage to itself in a cycle, because the 6.25 damage works this way.
  • Burgundian Hand Cannoneers actually deal +3 vs Condottieri, so unlike the description of Condottieri, they do receive attack bonus, albeit small.
  • Bohemian Pikemen deal $22 * 1.25 - 16 = 12$ bonus damage to Elite Cataphract, while regular Pikemen on a hill deal $(22 - 16) \times 1.25 = 7.5$ bonus damage to Elite Cataphracts. This example is meant to clarify the difference between +25% attack and +25% damage. Similarly, Burgundian Gunpowder bonus gives +25% attack, while being on top of hill gives +25% damage. These wordings make it clear that the attack boost of Burgundian Gunpowder units comes in before starting the damage calculation while the hill bonuses apply after calculating the intermediate damage values.
• Not every unit with an attack bonus against another unit can be called a counter. The Spearman line has +1 vs the Eagle Scout line, but get wrecked by them. Elite Samurai have +12 vs Elite Longboats and Elite Longbowmen, but cannot counter them with realistic assumptions. Hand Cannoneers have +2 (+3 for Burgundians) vs Rams but perform poorly.
• Despite not having bonuses, a unit can be called a counter to the other unit. The obvious example of this is a Monk. The Scout Cavalry line, the Knight line, and Steppe Lancers are pretty strong counter to siege units. Mangonels can be called a reasonable counter to Crossbowmen. Arbalesters are a fairly good counter to Hand Cannoneers.
• Despite having a meagre difference of 1 pierce armor, the Spearman line is nowhere near to the Militia line in resisting archer fire. This is because reliably every archer unit has an attack bonus vs Spearmen. The Archer line, Skirmishers, and Genitours do +3. Regular Cavalry Archers and unique foot archers do +2. Elite Skirmishers and Heavy Cavalry Archers do +4. Kipchaks, Mangudai, Slingers, and Hand Cannoneers do +1. Most notably, Genoese Crossbowmen and Camel Archers do not receive any attack bonus. Elephant Archers also do not receive any attack bonus until Parthian Tactics, but this maybe by design to make them weak to the Spearman line.
• Despite both Halberdiers and Genitours having attack bonus vs the other, neither unit is called a counter to the other. The same idea goes for Jaguar Warrior vs Samurai and Genoese Crossbowmen vs Genitours.

Examples

Karambit Warrior against Eagle Warrior

Values	Karambit Warrior Attack	Eagle Warrior Armor
Melee (4)	7	0
Pierce (3)	-	3
Eagle (29)	2	0
Infantry (1)	-	0

A Karambit Warrior has a base melee attack of 7, no pierce attack, and an attack of 2 against the Eagle Warrior. 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: $(7-0) [melee] + (2-0) [Eagle] = 9$ damage. The pierce armor does not come into play as the Karambit Warrior does not have a pierce attack.

Plumed Archer against Spearman vs Plumed Archer against Man-at-Arms

Values	Plumed Archer Attack	Spearman Armor	Man-at-Arms Armor
Pierce (3)	5	0	1
Infantry (1)	1	0	0
Spearman (27)	2	0	-

A Plumed Archer has a pierce attack of 5, an attack of 1 against Infantry armor class, and an attack of 2 against the Spearman armor class. A Spearman has a melee armor of 0, a pierce armor of 0, an Infantry armor of 0, and a Spearman armor of 0. If the Plumed Archer now hits the Spearman, it deals: $(5-0) [pierce] + (2-0) [Spearman] + (1-0) [Infantry] = 8$ damage. A Man-at-Arms has a melee armor of 0, a pierce armor of 1, an Infantry armor of 0, and no Spearman armor. If the Archer now hits the Man-at-Arms, it deals: $(5-1) [pierce] + (1-0) [Infantry] = 5$ damage. The bonus damage against Spearmen is not triggered, because the Man-at-Arms does not have the corresponding armor class. This example explains how armor classes are used to show when different armor classes come into play.

Burgundian Hand Cannoneer against Condottiero

	Generic Hand Cannoneer Attack	Hand Cannoneer Attack	Condottiero Armor
Pierce (3)	17	$round (17 * 1.25) = 21$	0
Infantry (1)	10	$round (10 * 1.25) = 13$	10
Damage dealt	17	24

A Hand Cannoneer has a base pierce attack of 17, no melee attack, and an attack of 10 against Infantry. Burgundians have a civilization bonus that increases all existing attacks of gunpowder units by 25%, viz Base pierce, anti-infantry, and anti-spearman attacks. A fully upgraded generic Condottiero has a melee armor of 1, a pierce armor of 0, and an Infantry armor of 10. In this example, the Burgundian Hand Cannoneer is doing approx. 41% more damage to the Condottiero, despite having only +25% attack, which shows having an attack boost against armored units is much stronger than having an equal damage (say due to a hill) boost.

Spearman against Sicilian Scout Cavalry

	Generic Spearman Attack	Generic Scout Cavalry Armor	Scout Cavalry Armor
Melee (4)	3	0	0
Cavalry (8)	15	0	0
Bonus Damage Resistance		0	33%
Damage dealt		3 + 15 = 18	$3 + 15 * 0.67 = 13.05$

A Spearman with no upgrades has a base melee attack of 3, no pierce attack, and an attack of 15 against Cavalry. A Scout Cavalry with no upgrades has a melee armor of 0, a pierce armor of 2, and a Cavalry armor of 0. Sicilian Scouts receive 33% less bonus damage as consequence of their civilization bonus. The generic Scout Cavalry receive 18 damage, or 15 bonus damage, as expected. The Sicilian Scout Cavalry receive an odd 13.05 damage, which appears as 14 damage on the first hit and 13 damage afterwards. This example explains how bonus damage resistance works.

Elite Skirmisher against Bengali Elephant Archer

	Elite Skirmisher Attack	Generic Elephant Archer Armor	Elephant Archer Armor
Pierce (3)	3	2	2
Archer (15)	4	0	0
Cavalry Archer (28)	2	-4	-4
Bonus damage resistance		0	25%
Pierce damage taken		$3-2=1$	$3-2=1$
Bonus damage taken		$(4-0) + (2-(-4)) = 10$	$[(4-0) + (2-(-4))]*0.75 = 7.5$

Elephant Archers have a -4 cavalry archer armor. Bengali Elephant units have 25% bonus damage resistance. This example shows how bonus damage resistance works against non-zero values of armor classes.

Gurjara Camel Rider against Bengali Armored Elephant

	Camel Rider Attack	Generic Armored Elephant Armor	Armored Elephant Armor
Melee (4)	6	-2	-2
Melee damage taken		$6-(-2)=8$	$6-(-2)=8$
Cavalry (8)	$round(9 * 1.4) = 13$	7	7
Bonus Damage Resistance		0	25%
Bonus damage taken		$13-7 = 14$	$(13-7)*0.75 = 12.5$

A Camel Rider with no upgrades has a base melee attack of 6 and an attack of 9 against Cavalry. Gurjaras have a civilization bonus that increases all bonus attacks (viz cavalry, camel, ship, Mameluke, Fishing Ships, and Standard Building damage) of the unit line by 40% in Imperial Age. Armored Elephants have -2 melee, 140 pierce, 7 cavalry, and 17 elephant armor. Bengali Armored Elephants receive 25% less bonus damage as a consequence of their civilization bonus.

Gurjara mounted units

Originally, the Gurjara mounted unit bonus was +50% attack, which was reduced to +40%. With update 73855, the bonus was staggered by Age into +20%/+30%/+40%. However, initially the bonus was bugged. While it may look like the effect was the same +40% in Imperial Age, it was not. The anomaly occurred due to the step 1 of our formula - The attack bonuses are calculated and stored after rounding off as integers. Since the attack boost applies on the stored numbers, the next stage of the bonus applies on the rounded off values.

Before we dive in the table, we should know how the bonus was staggered. Units get +20% bonus in Feudal Age directly. Upon hitting Castle Age, units got another +8%, for a total of $1.2 \times 1.08 = 1.296$ times the effect. Upon hitting Imperial Age, units got another +8%, for a total of $1.296 \times 1.08 = 1.39968$. The bonus at the end was not +40%, but +39.968%, but it was not the cause of our problem. Now that we have the behind the scenes knowledge of the bonus, we can go for the application of the bonus.

The following table shows how the bonus should work (T - theoretical) and how it actually worked (P - practical). The +20% column will always have same values for theoretical and practical since the bonus is applied directly. The numbers in brackets are actual values that need to rounded off. The practical values are the previous practical values multiplied by 1.08 and the theoretical values are the attack bonus values multiplied by the intended value.

Old staggered bonus values

Attack bonus value	+20%	T: +30%	P: +30%	T: +40%	P: +40%	Unit matchups	Previous +50%
1	1 (1.2)	1 (1.3)	1 (1.08)	1 (1.4)	1 (1.08)	Elite Kipchak vs Spearmen Poles' team bonus	2 (1.5)
2	2 (2.4)	3 (2.6)	2 (2.16)	3 (2.8)	2 (2.16)	Camel Scout vs Camels Elite Genitour vs Cavalry Archers Genitours vs Spearmen Hindustanis' team bonus	3
4	5 (4.8)	5 (5.2)	5 (5.4)	6 (5.6)	5 (5.4)	Camel Scout vs Cavalry Genitour vs Archer	6
5	6	7 (6.5)	6 (6.48)	7	6 (6.48)	Camel Rider vs Camels Elite Genitour vs Archer	8 (7.5)
6	7 (7.2)	8 (7.8)	8 (7.56)	8 (8.4)	9 (8.64)	Scout Cavalry vs Monks	9
7	8 (8.4)	9 (8.64)	9 (9.1)	10 (9.72)	10 (9.8)	Heavy Camel Rider vs Mamelukes	11 (10.5)
9	11 (10.8)	12 (11.7)	12 (11.88)	13 (12.6)	13 (12.96)	Camel Rider vs Cavalry Heavy Camel Rider vs Camels	14 (13.5)
10	12	13 (12.96)	13	14 (14.04)	14	Light Cavalry vs Monks	15
12	14 (14.4)	16 (15.6)	15 (15.12)	17 (16.8)	16 (16.2)	Hussar vs Monks	18
18	22 (21.6)	23 (23.4)	24 (23.76)	25 (25.2)	26 (25.92)	Heavy Camel Rider vs Cavalry	27
25	30	33 (32.5)	32 (32.4)	35	35 (34.56)	Armored Elephant vs Siege	38 (37.5)
35	42	46 (45.5)	45 (45.36)	49	49 (48.6)	Siege Elephant vs Siege	53 (52.5)
75	90	98 (97.5)	97 (97.2)	105	105 (104.76)	Armored Elephant vs Buildings	113 (112.5)
105	126	137 (136.5)	136 (136.08)	147	147 (146.88)	Siege Elephant vs Buildings	158 (157.5)

The values colored in Red are unintended nerfs and the values colored in Green are unintended buffs. Camels and Ships take the same bonus damage, so the mention of attack bonus vs Ships was dropped due to repetition, but that matchup is equally affected as the matchup against Camels. The bonus to the Hindustani and the Polish team bonus did not apply before this patch.

With update 78174, the bonus was changed in the Castle Age from +8% to +11% and was reduced in Imperial Age from +8% to +5%. This helped some units to cross the .5 border and round off the the ceiling value. The most notable matchup corrected was Camel Riders vs other camels. However, some values like those of Armored Elephants vs buildings increased more than intended, in which case it is visible that the bonus is overcompensated.

Current staggered bonus values

New nerf

Old unfixed nerf

Fixed

Old unfixed buff

New buff

Attack bonus value	+20%	T: +30%	New +30%	Old +30%	T: +40%	New +40%	Old +40%	Unit matchups
1	1 (1.2)	1 (1.3)	1 (1.11)	1 (1.08)	1 (1.4)	1 (1.05)	1 (1.08)	Elite Kipchak vs Spearmen Poles' team bonus
2	2 (2.4)	3 (2.6)	2 (2.22)	2 (2.16)	3 (2.8)	2 (2.1)	2 (2.16)	Camel Scout vs Camels Elite Genitour vs Cavalry Archers Genitours vs Spearmen Hindustanis' team bonus
4	5 (4.8)	5 (5.2)	6 (5.55)	5 (5.4)	6 (5.6)	6 (6.3)	5 (5.4)	Camel Scout vs Cavalry Genitour vs Archer
5	6	7 (6.5)	7 (6.66)	6 (6.48)	7	7 (7.35)	6 (6.48)	Camel Rider vs Camels Elite Genitour vs Archer
6	7 (7.2)	8 (7.8)	8 (7.77)	8 (7.56)	8 (8.4)	8 (8.4)	9 (8.64)	Scout Cavalry vs Monks
7	8 (8.4)	9 (8.64)	9 (8.88)	9 (9.1)	10 (9.72)	9 (9.45)	10 (9.8)	Heavy Camel Rider vs Mamelukes
9	11 (10.8)	12 (11.7)	12 (12.21)	12 (11.88)	13 (12.6)	13 (12.6)	13 (12.96)	Camel Rider vs Cavalry Heavy Camel Rider vs Camels
10	12	13 (12.96)	13 (13.32)	13	14 (14.04)	14 (13.65)	14	Light Cavalry vs Monks
12	14 (14.4)	16 (15.6)	16 (15.54)	15 (15.12)	17 (16.8)	17 (16.8)	16 (16.2)	Hussar vs Monks
18	22 (21.6)	23 (23.4)	24 (24.42)	24 (23.76)	25 (25.2)	25 (25.2)	26 (25.92)	Heavy Camel Rider vs Cavalry
25	30	33 (32.5)	33 (33.3)	32 (32.4)	35	35 (34.65)	35 (34.56)	Armored Elephant vs Siege
35	42	46 (45.5)	47 (46.62)	45 (45.36)	49	49 (49.35)	49 (48.6)	Siege Elephant vs Siege
75	90	98 (97.5)	100 (99.9)	97 (97.2)	105	105	105 (104.76)	Armored Elephant vs Buildings
105	126	137 (136.5)	140 (139.86)	136 (136.08)	147	147	147 (146.88)	Siege Elephant vs Buildings

Trivia

• 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 and 4.
• Logically speaking a unit should have only one attack class in 3 or 4, but there are units which deal both melee damage and pierce damage. In such cases the melee damage is hidden because the UI shows the greatest values among these two attacks, so the units may receive some pseudo bonus damage. These units are Chu Ko Nu, secondary projectiles of Chu Ko Nu and Kipchaks (they are the same projectile), Scorpions (but not the secondary projectile from Double Crossbow), and the Fire Galley line. Among these, only Fire Ships and Fast Fire Ships have non zero values for the melee attack.
• The Conquistador (Cavalry, Archer, Unique unit, Gunpowder unit, and Cavalry archer),Genitour (Cavalry, Archer, Unique unit, Cavalry Archer and Skirmisher) and Ballista Elephant (Cavalry, Elephant, Unique unit, Siege weapon, and Heavy Siege) have the most armor classes of all units, at five.
• 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. Trees, Herdables (Cows, Sheep, etc.) and Showpiece units (like Butterflies, Hawks, and Stormy Dogs) also have base armor zero. All other units have 10,000 base armor.
  • This explains why a Scout Cavalry having 3 attack can kill a sheep in 1 hit only, because the Sheep is also receiving +6 attack of Scouts against Monks. Also, Camel Scouts deal only 2 damage per hit to sheep, because they do not have any attack bonus in Dark Age, and take 4 hit to kill a sheep. Similarly, this affects the Shepherds. which have 3 melee attack, +3 vs all buildings, +6 vs Stone Defenses.
  • Trees have 0 base armor, which means that all units which can attack trees (lumberjacks, Ballista Elephants, and Onagers) attack with all attacks present. In addition to having regular attacks, lumberjacks also have +3 vs Trees, which helps only against Trees with 30 HP. This explains why researching Sappers enables villagers to cut down any tree in a single hit.
• No unit actually has Armor Class 33, but the secondary projectiles of Organ Guns and Hussite Wagons have a whopping 10,002 attack of class 33.
  • This means that all units which they target suffer 2 damage, irrespective of mishit. This is because these projectiles (along with Arambai and Chakram Thrower) have a special property to do full damage to mishits as well.
  • A side effect is that Organ Guns and Hussite Wagons are actually the best units to kill hero wolves 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 and Hussite Wagons can do this from a safe distance.
• The Mosque has no armor classes (not even classes 3, 4, 11, or 21), meaning all attacks, even from Trebuchets or Petards with Siege Engineers, will do only 1 damage. However, following the above paragraph, secondary projectiles of Hussite Wagons and Organ Guns will deal 2 damage.
• 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 assigned. However, using the Scenario Editor, their attack bonus against unique units can be modified. This is the main reason why several units have 0 attack against certain armor classes, so that they can benefit from technologies (such as Chieftains) and/or bonuses (such as the Saracen team bonus) that increase such attack values.
• The upgrade lines of Skirmishers, Camel Riders, Mangonels, Rams, Armored Elephants, Galleys, Fire Galleys, and Bombard Cannons all deal bonus damage against an armor class they are themselves part of. The civilization-unique Samurai, Jaguar Warrior, Legionary, Camel Archer, Genitour, Mameluke (only Elite), Longboat, Chakram Thrower (only Elite), Thirisadai, and Caravel do as well. Japanese Cavalry Archers do as well. While the main projectiles of Ballista Elephants, towers, and Donjons do not deal bonus damage against themselves, the secondary projectiles do.
• Condottieri were responsible for the creation of two 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 negate anti-infantry attack from gunpowder units only. Since Dawn of the Dukes, Winged Hussars also do bonus damage against the gunpowder units.
• The game considers all attacks except those of class 3, 4, 31, and 33 as attack bonuses. The attribute attack bonus resists (multiplier) can be used to reduce all incoming attack bonuses (not hill bonuses) by a constant factor for a unit. This factor maybe different for different units, but is same for all armor classes on the same unit.
• No unique upgrade of a regular unit is in the unique unit armor class. The reason is simple: an upgrade should not make the unit worse. Flemish Militia are implemented as replacing Villagers by Flemish Militia with the same percentage hit points remaining, so they do not count as upgrade.
  • Docks when upgraded to Harbors get the Stone defense armor class added. This is the only exception.
• Unit classes and armor classes are completely different. Unit classes are unique, such as Eagle Warriors and Champions being Infantry; Ballista Elephants, Camel Riders, and Hussars being Cavalry; and Missionaries being Monks. Unit classes dictate unit properties like garrison, conversion (buildings and siege need Redemption), adding arrows when garrisoned, and most importantly upgrades, while armor classes just dictate which units receive attack bonus from which units.
  • Usually, units having a particular armor class can be said to be of a particular type, which is what causes confusion among players. Notable exceptions are Arambai and Conquistadors (Cavalry archer armor class, but Conquistador unit class) and Armored and Ballista Elephants (Siege armor classes, but Cavalry unit class).
• Among all unit upgrades, the following provide the most resistance against attack bonuses:
  • Elite Cataphract (from 12 cavalry armor to 16).
  • Elite Genitour (from 0 cavalry archer armor to 1).
  • Battering/Capped/Siege Rams have 0/1/2 ram armor.
  • Siege Elephant (from 7 cavalry armor to 10, from 17 elephant armor to 20).
• Among buildings, the Fortified Wall upgrade increases the building armor of Stone Walls from 16 to 24.

Changelog

The Age of Kings

• Basic unit armor classes exist - Infantry, Archers, Cavalry, Siege Weapons, Ships.
• Default Base Armor was 232.
• Supporting unit classes added to boost some units against others - Rams (for ranged units), War Elephants (for Spear units and Scorpions), Unique units (for Samurai).
• Camels and Cavalry are in the same armor class.
• Wild Boars and Siege Weapons are in the same armor class.
• Basic building armor classes exist - Building, Standard Building and Stone Walls & Gates & Towers.
• Trees Armor class exists for Lumberjacks to kill trees in 1 less hit situationally (like uphill trees, or trees with 30 HP).

The Conquerors

• Default Base Armor increased to 1,000, due to Petards having massive attack bonuses.
• Camels (except Mamelukes) are removed from Cavalry Armor class, and placed in Ship Armor class. Mamelukes receive Ship Armor class, while gaining +11 armor in Cavalry Armor class.
• Wild Boars are removed from Siege Weapons Armor class, and given their own armor class, for Goth villagers to have +6 attack bonus vs them.
• Spearman line is given its own Spearman Armor class, which makes it weaker to ranged units.
• Cavalry Archer line and Mangudai are given their own Cavalry Archer Armor class, which makes them weaker to Elite Skirmishers.
• Monks receive their own Monk Armor class, which makes scouting units more efficient at killing them.
• Castles receive their own Castle Armor class, which was introduced for Tarkans and Petards.
• Walls and Gates receive their own Walls and Gates Armor class, which was introduced for Tarkans and Petards.
• Eagle Armor class introduced to make Eagle units weaker to other infantry units.
• Turtle Ship Armor class introduced to make Turtle Ships weak vs Fire Ships, and strong vs other warships.

The Forgotten

• Predator Animals Armor class was introduced for Magyar villagers to have +30 attack bonus vs Wolves.
• Turtle Ships were included in Unique units armor class, despite the latter's description contradicting it.
• Gunpowder units armor class was introduced for the Condottiero to have attack bonus vs Gunpowder units.

The African Kingdoms

• With patch 4.8, Camels are removed from the Ship Armor class, and are given their own Camel Armor class.

Rise of the Rajas

• With patch 5.7, Fishing Ships are removed from Ship Armor class, and given their own Fishing Ship Armor class, which essentially grants +2 armor against Fire Galley attacks. Fishing Ship Armor class is identical to Ship Armor class, against all other units.
• With patch 5.7, Condottieri are given their own Condottiero armor class, which essentially negates +10 Infantry armor against non-gunpowder units.
• With patch 5.8, Mamelukes are removed from Cavalry Armor class, and given their own Mameluke Armor class, which essentially grants another +10 armor against Halberdier attacks. Mameluke Armor class is identical to Cavalry Armor class (+11) against all other units.

The Last Khans

• Armor class 31 was introduced for the Leitis to ignore melee armor of units, but not buildings.

Lords of the West

• The concept of bonus damage resistance is introduced. Bonus damage resistance is applied to attack bonus of enemy unit first, and then the result is subtracted from corresponding armor.

Dawn of the Dukes

• Heavy Siege armor class introduced to make Hussite Wagons take double melee damage from ranged siege weapons.

Dynasties of India

• Armor class 31 is now obsolete. Armor-ignoring attacks are implemented using Attack-enhancing properties, instead of armor class. The armor values still exist in the game files as they were before Dynasties of India.
• Update 66692: Bonus damage resistance is now applied after subtracting bonus armor from bonus attack. This buffs units with negative armor (like Elephant Archers), and nerfs units with positive armor (like Armored Elephants). Units without bonus armor are not affected.
• With update 73855, default Base Armor is increased to 10,000, probably for multiple research mods like 256x.
  • The attack of secondary projectiles of Hussite Wagon and Organ Gun has been increased from 1,002 to 10,002 to keep the same effect.
• Gurjaras: Update 78174 corrects rounding errors in the bonus damage of some units from the civilization bonus.
• With update 81058:
  • Skirmisher and Genitour lines given its own Skirmisher Armor class, which makes them weaker to Bengali cavalry.
  • With the reworking of Royal Heirs, armor class 39 and a new mechanic was introduced. Armor class 39 carries the attack of mounted units specifically as a negative value.
  • Ballista Elephants gain the Heavy Siege armor class with +20 armor.

Bugs

• Class 11 is named "All Buildings (except Port)" in the game files. Port was a useless hidden building in The Age of Kings, which was removed later. It never made an official appearance.
• Even though Turtle Ships are in class 19, the class is named "Unique Units (except Turtle Ship)" in the game files since The Conquerors. This name is used because Turtle Ships were not in this armor class back in The Conquerors.
• The Gurjara bonus of +30%/+40% attack bonus for mounted units in Castle/Imperial Age is inconsistent.