Editing Damage (section)

== Damage calculation of creature stacks ==
=== The damage calculation formula ===
{| class="wikitable" style="margin: 0 0 0 1em; float:right;"
|+ <big>'''Table 1: Damage calculation variables'''</big>
|- 
! {{-}}Description{{-}}
|- 
| {{-}}DMG<sub>b</sub> = Base damage
|- 
| {{-}}I<sub>1</sub>&thinsp;&thinsp; = 0.05 &times; ([[Attack]] - [[Defense]]) (if A ≥ D)
|-
| {{-}}I<sub>2</sub>&thinsp;&thinsp; = 0.10, 0.25, 0.50 for basic, advanced, expert [[Archery]]<br>
&ensp;&thinsp;&thinsp;&thinsp;&thinsp;&thinsp;&thinsp;&thinsp;= 0.10, 0.20, 0.30 for basic, advanced, expert [[Offense]]{{-}}
|-
| {{-}}I<sub>3</sub>&thinsp;&thinsp; = 0.05 &times; I<sub>2</sub> &times; hero level for Archery/Offense [[Hero_specialty#Secondary_skill_specialties|specialty]]
&emsp;&thinsp;&thinsp;&thinsp;&thinsp;= 0.03 &times; (hero '''&divide;''' creature level) for [[Adela]]'s [[bless]]<br> 
|-
| {{-}}I<sub>4</sub>&thinsp;&thinsp; = 1.00 for [[luck]]y strikes
|-
| {{-}}I<sub>5</sub>&thinsp;&thinsp; = 2.00 for [[Cannon]]{{-wh}} triple damage<br>
&emsp;&thinsp;&thinsp;&thinsp;&thinsp;= 1.00 for [[Death Blow]], [[Ballista]] or cannon{{-wh}} double damage<br> 
&emsp;&thinsp;&thinsp;&thinsp;&thinsp;= 1.00 if [[Elemental]] attacks opposite [[Elemental]] type<br>
&emsp;&thinsp;&thinsp;&thinsp;&thinsp;= 0.50 for [[hate]]<br>
&emsp;&thinsp;&thinsp;&thinsp;&thinsp;= 0.05 &times; [[hex]]es travelled for [[Cavalier]]s, [[Champion]]s
|-
| {{-}}R<sub>1</sub> = 0.025 &times; ([[Defense]] - [[Attack]]) (if D ≥ A)
|-
| {{-}}R<sub>2</sub> = 0.05, 0.10, 0.15 for basic, advanced, expert [[Armorer]]
|-
| {{-}}R<sub>3</sub> = 0.05 &times; R<sub>2</sub> &times; hero level for Armorer [[Hero_specialty#Secondary_skill_specialties|specialty]]
|-
| {{-}}R<sub>4</sub> = 0.15, 0.30 for basic, advanced/expert level [[Shield]]<br>
&emsp;&ensp;&thinsp;= 0.25, 0.50 for basic, advanced/expert level [[Air Shield]]
|-
| {{-}}R<sub>5</sub> = 0.50 if attacker has [[range penalty|range]] or [[melee penalty]]{{-}}
|-
| {{-}}R<sub>6</sub> = 0.50 if target is behind a wall ([[obstacle penalty]]){{-}}
|-
| {{-}}R<sub>7</sub> = 0.50 for retaliation after being [[Blind]]ed<br>
&emsp;&ensp;&thinsp;= 0.75 for retaliation after advanced [[Blind]]<br>
&emsp;&ensp;&thinsp;= 0.50 for shooter with basic [[Forgetfulness]]<br>
&emsp;&ensp;&thinsp;= 0.50 for shooter's melee attack with [[Forgetfulness]]
|-
| {{-}}R<sub>8</sub> = 0.50 for Psychic Elemental vs. [[mind spell]] immunity<br>
&emsp;&ensp;&thinsp;= 0.50 for Magic Elemental vs. lvl 1-5 [[spell immunity]]<br>
&emsp;&ensp;&thinsp;= 0.50 if target is [[Petrify|petrified]]<br>
&emsp;&ensp;&thinsp;= 0.75 for retaliation after being [[paralyze]]d
|-
| {{-}}R<sub>9</sub> =  0.50 for [[Luck|unlucky]] {{wh}} strikes 
|}

Mathematical formula for calculating the final damage (DMG<small>f</small>) is:

{{Math|DMG<sub>f</sub> <nowiki>=</nowiki> DMG<sub>b</sub> &times; (1 + I<sub>1</sub> + I<sub>2</sub> + I<sub>3</sub> + I<sub>4</sub> + I<sub>5</sub>) &times; (1 - R<sub>1</sub>) &times; (1 - R<sub>2</sub> - R<sub>3</sub>) &times; (1 - R<sub>4</sub>) &times; (1 - R<sub>5</sub>) &times; (1 - R<sub>6</sub>) &times; (1 - R<sub>7</sub>) &times; (1 - R<sub>8</sub>) &times; (1 - R<sub>9</sub>{{wh}})}}

Primary determinant for the final damage is the base damage (DMG<sub>b</sub>), which is affected by the number of attacking creatures and their damage range. All other variables are basically modifiers of the base damage. Variables are denoted as I if they (i)ncrease damage and as R if they (r)educe it. I<sub>1</sub> and R<sub>1</sub> are mutually exclusive, but all other variables may simultaneously affect the final damage (DMG<sub>f</sub>). A brief summary of the variables have been given in the table on the right. To summarize the above formula, the content in the first parentheses increase the base damage by multiplying it with a modifier varying from 1.00 to 8.00, and the content in the second parentheses reduces the damage with a modifier varying from ~0.01 to 1.00.

=== Offense variables ===
==== Base damage – variable DMG<sub>b</sub>  ====

Damage range for a single unit type is displayed in its stats. Base damage for a stack of creatures is calculated as such:

* If there are less than or equal to 10 creatures in a stack then a random integer is chosen in a damage range for each creature, and they are added up. 
* If there are more than 10 creatures in a stack, 10 random integers are chosen in a damage range of the creature  and  added up.  The  result  is  multiplied  by  N/10,  where N is  the  number  of  creatures in the stack, and rounded down.

==== Attack-Defense difference – variables I<sub>1</sub> and R<sub>1</sub> ====
The Attack-Defense difference (ADD), denoted by I<small>1</small> and R<small>1</small> in the formula, is typically the main modifier of the base damage. It is calculated as the difference between the attacker's attack value and the defender's defense value. These are determined by adding up the attack skill of the attacking hero and of the attacking creature type, and by adding up defense skill of the defending hero and defending creature type. Spells and creature abilities that affect attack or defense values, such as [[Bloodlust]] or [[disease]], are also taken into account in this part of the formula, as are any bonuses from [[native terrain]] or hero's [[Hero_specialty#Creature_specialties|creature specialties]].

If the attacking creature's total attack value is higher than the defending creature's total defense value (i.e., the difference is positive), then the attacking creature receives a 5% bonus to its base damage for every point the attack value is higher. If the difference is negative, then the attacking creature receives a 2.5% penalty to its total damage for every point the attack value is lower. A positive ADD therefore increases damage, meaning that the variable I<small>1</small> in the formula is positive whereas R<sub>1</sub> is 0. Conversely, a negative ADD decreases damage, meaning that R<small>1</small> is positive whereas I<small>1</small> is 0. An Attack-Defense difference of 0 does not modify base damage.

The ADD can modify base damage only up to +300% (400% damage dealt) if ADD is positive, and up to -70% (30% damage dealt) if ADD is negative. These limits are reached by a positive ADD of +60 and a negative ADD of -28. This means that a high attack skill can grant no more than +300% bonus damage, whereas a high defense skill can grant no more than a -70% penalty. Thus, the Attack-Defense difference can modify a base damage of 100 to no more than 400, and to no less than 30.

==== Secondary skill factors – variables I<sub>2</sub> and I<sub>3</sub> ====
Variable I<sub>2</sub> represents [[secondary skill]] modifier of either [[Archery]] or [[Offense]] depending on the attack type. Creatures able to [[Ranged attack|attack from the distance]] gain bonus from the Archery secondary skill when using their ability, and if a creature engages into [[melee]] combat, it gains bonus to its damage from Offense secondary skill. For ranged attacks, Archery secondary skill may give 0, 0.10, 0.25 or 0.50 for I<sub>2</sub> depending on what level the skill is (if any). Similarly, Offense may give 0, 0.10, 0.20 or 0.30 to melee attacks. Because creatures cannot peform ranged and melee attacks at the same time, Archery and Offense modifiers cannot affect damage simultaneously.

Variable I<sub>3</sub> is related to Archery and Offense modifiers through heroes who specilize in these skills. There are three heroes specializing in Archery or Offense; Orrin specializes in Archery, while Gundula and Crag Hack specialize Offense (also Corkes in HotA). They receive additional bonus from Archery or Offense secondary skill, as calculated with the following formula:

<big><code>I<sub>3</sub> = 0.05 &times; hero level &times; I<sub>2</sub></code></big>

As can be seen from the formula, the specialty bonus requires that the hero has the appropriate secondary skill, otherwise I<sub>2</sub> becomes 0, which leads I<sub>3</sub> to become 0 as well. In other words, Orrin does not receive his specialty bonus if he does not have Archery secondary skill; same applies to Gundula and Crag Hack with Offense (also Corkes in HotA). By default these heroes start with the skill they specialize in, but in custom maps the map-maker may change the starting skills.

A special case of the variable I<sub>3</sub> is [[Adela]] and her [[Bless]] specialty. Adela's Bless maximizes base damage as usual, but also deals extra damage according to the following formula:

<big><code>I<sub>3</sub> = 0.03 &times; hero level &divide; creature level</code></big>

Because of the division, Adela's Bless bonus is greater for low-tier creatures. Her Bless grants +3% damage per her level to 1st level creatures, whereas it grants +0.6% per her level for 5th level creatures.

==== Luck as combat modifier – variable I<sub>4</sub> ====
The [[luck]] variable may be either 0 or 1.00, depending on whether or not the attacking creatures gets "a lucky strike". This is determined by the combat variable luck, which may be 0 (neutral), +1 (positive), +2 (good) or +3 (excellent). These values determine how often lucky strikes occur. These probabilities are, respectively, 0/24 (0%), 1/24 (4.17%), 1/12 (8.33%) and 1/8 (12.5%). Luck may be affected by artifacts, creature special abilities, adventure map locations, spells and the [[Luck (secondary skill)|Luck]] secondary skill.

==== Creature abilities – variable I<sub>5</sub> ====
The final variable capable of increasing total damage is I<sub>5</sub>, which denotes creature specialties from [[Cavalier and Champion|Cavaliers and Champions]], [[Dread Knight]]s, [[Ballista]]s, [[Cannon]]s{{-wh}}, [[elemental]]s, and creatures that [[hate]] each other. Dread Knights may deliver [[Death Blow]]s, which gives variable I<sub>5</sub> a value of 1.00, effectively doubling base damage (though not necessarily total damage). The I<sub>5</sub> variable is also 1.00 for a ballista or cannon{{-wh}} whose shots deal double (base) damage, and 2.00 for cannon's triple damage. Additionally, there are a few creatures who [[hate]] each other, which gives I<sub>5</sub> a value of 0.50 when they attack each other. This is true for [[Angel]]s and [[Devil]]s, [[Titan]]s and [[Black Dragon]]s, and [[Genie]]s and [[Efreet]]i. Although [[Fire Elemental]]s and [[Water Elemental]]s, as well as [[Air Elemental]]s and [[Earth Elemental]]s do not hate each other, they also do double base damage against each other (i.e., I<sub>5</sub> = 1.00). Finally, unless they are attacking [[Pikeman and Halberdier| pikemen or halberdiers]], the jousting specialty of Cavaliers and Champions lets them deal 5% extra damage for every hex they travel during the combat turn in which they attack their target:

<big><code>I<sub>5</sub> = 0.05 &times; squares travelled</code></big>

=== Defense only variables ===
==== Secondary skill factors – variables R<sub>2</sub> and R<sub>3</sub>====
Similarly to the variables I<small>2</small> and I<small>3</small> variables R<small>2</small> and R<small>3</small> denote how [[Armorer]] and specializing in the skill affects the value of final damage. The reduction due to Armorer is not dependable on the attack type, but is the same for both ranged and melee damage. R<small>2</small> can receive values 0, 0.05, 0.10 or 0.15, respectively indicating that a hero does not posses the skill, has it on basic, advanced or expert level. The three heroes with an Armorer specialty - [[Mephala]], [[Neela]] and [[Tazar]] - increase the effectiveness of Armorer secondary skill by 5% for every level. Thus, as can be seen from the following formula, they double the effectiveness of the Armorer skill when they reach level 20:

<big><code>R<sub>3</sub> = 0.05 &times; Hero level &times; R<sub>2</sub></code></big>

Armorer has two unexpected side effects. First, heroes with Armorer take extra damage from [[arrow tower]]s. The damage reduction is reversed, as if the sign within the parenthesis would be plus instead of minus. Second, damage is reduced by 1 if creatures from a hero with Armorer take an amount of damage that is exactly an integer value. Thus, if 100 [[Peasant]]s attack a stack of Peasants commanded by a hero with basic Armorer (and the ADD is 0), damage is not 100 &times; 1 &times;(1 - 0.05) = 95, but 94. If the attack had instead been performed by 99 Peasants, the damage would be 99 &times; 1 &times;(1 - 0.05) = 94.05, which is not an integer value and therefore rounded off in the usual way, that is, to 94.

==== Magic shields - variable R<sub>4</sub> ====
There are many spells that modify damage, but most do so by increasing or decreasing the attack and defense skills of allied or enemy troops. [[Stone Skin]], for example, increases an allied unit's defense skill, and therefore modifies damage by affecting variable R<sub>1</sub>. The only spells that modify damage directly are [[Shield]], [[Air Shield]], and [[Forgetfulness]]. Shield reduces all [[melee]] damage done to the hero's troops by 15% (R<small>4</small> = 0.15), or even by 30% when cast with advanced or expert proficiency. [[Air shield]] reduces all [[ranged attack|ranged]] damage done to the hero's troops by 25% (R<small>4</small> = 0.25), or by 50% when cast with advanced or expert proficiency. Similarly to Armorer and arrow towers, also Air Shield actually increases the damage from arrow towers instead of decreasing it.

==== Range and Melee penalty - variable R<sub>5</sub> ====
[[Ranged attack|Ranged units]] do only 50% damage (R<small>5</small> = 0.50) to targets that are situated at a distance of ten or more [[hex]]es on the combat field. This range penalty is negated by [[Sharpshooter]]s and by heroes carrying the [[Golden Bow]] or [[Bow of the Sharpshooter]]. When a target occupies two hexes, it is possible for a range penalty to apply to the second hex, but not to the first hex the creature is standing on.

When a hex adjacent to a ranged unit is occupied by an enemy unit, the ranged unit is unable to shoot (i.e., blocked). It has to resort to melee attacks. This typically reduces its damage by 50% (R<small>5</small> = 0.50). However, [[Beholder]]s/[[Evil Eye]]s, [[Medusa]]s/[[Medusa Queen]]s, [[Magi]]/[[Arch Magi]], [[Zealot]]s, [[Enchanter]]s, [[Pirate]]s{{-wh}}/[[Corsair]]s{{-wh}}/[[Sea Dog]]s{{-wh}} and [[Titan]]s are the only ranged units that do not suffer from this [[melee penalty]].

==== Obstacle Penalty - variable R<sub>6</sub> ====
[[Ranged attack|Ranged units]] that during a siege attack a target behind the wall receive an [[obstacle penalty]] if the wall protecing the target is not destroyed. As a result, their damage is reduced by 50% (R<small>6</small> = 0.50). This damage is halved once again if a range penalty applies. The obstacle penalty is negated by [[Mage|Magi]], [[Arch Mage|Arch Magi]], [[Enchanter]]s and [[Sharpshooter]]s, and by heroes carrying the [[Golden Bow]] or [[Bow of the Sharpshooter]].

==== Mind spells - variable R<sub>7</sub> ====
The spell [[Blind]] is deactivated when a blinded creature stack is attacked. Any retaliation against this attack will not be at full strength. It will be at only 50% strength (R<small>7</small> = 0.50) when Blind is cast with basic or no proficiency, and at 25% (R<small>7</small> = 0.25) when cast with advanced proficiency. An attack that deactivates expert Blind cannot be retaliated against, but the targeted creature stack does retain its ability to retaliate against another attack in that same combat round. [[Unicorn]]s and [[War Unicorn]]s cast Blind with basic proficiency, unless the battle takes place on [[Magic Plains]]. 

Additionally, when [[Forgetfulness]] cast with basic or no proficiency, it causes half of an enemy creature stack to forget to use its ranged attack, effectively halving its ranged damage (R<small>7</small> = 0.50). Due to a bug, shooter's melee attack damage, affected by Forgetfulness, is also decreased by half (R<small>7</small> = 0.50) ''(fixed in {{hota}}{{-wh}})''.

==== Creature Specialties - variable R<sub>8</sub> ====

Damage may also be reduced by some special abilities from creatures:

* [[Psychic Elemental]]s deal half damage (R<small>8</small> = 0.50) against creatures that are immune to [[Mind spell]]s, such as [[Giant]]s and [[Undead]]. This is not affected by the [[Orb of Vulnerability]].
* [[Magic Elemental]]s deal half damage (R<small>8</small> = 0.50) against [[Magic Elemental]]s and [[Black Dragon]]s. This is not affected by the [[Orb of Vulnerability]], [[Anti-Magic]], or [[Magic Resistance]].
* Creatures that are petrified by a [[Basilisk]]'s [[Petrifying attack]] or a [[Medusa]]'s [[Stone gaze]] take 50% damage (R<small>8</small> = 0.50) from [[ranged attack|ranged]] and [[melee]] attacks. Taking damage also deactivates the effect. 
* Creatures that are paralyzed by a [[Scorpicore]]'s [[Paralyzing Venom]] retaliate at only 25% of their full strength against the attack that deactivates the effect.

A special case of damage calculation concerns the spell and creature ability [[Fire Shield]]. [[Efreet Sultan]]s and any creatures that have Fire Shield cast on them counter-inflict damage from [[melee]] attacks. This is calculated as follows:

<big><code>Fire Shield damage =  FS &times; DMG<sub>b</sub> &times; (1 + I<sub>1</sub> + I<sub>2</sub> + I<sub>3</sub> + I<sub>4</sub> + I<sub>5</sub>)</code></big>

FS is a percentage that equals 0.20 for Efreet Sultans and (basic) Fire Shield, 0.25 for advanced Fire Shield, and 0.30 for expert Fire Shield.

==== Unluck as combat modifier - variable R<sub>9</sub> ====
[[Horn of the Abyss]] {{wh}} introduced negative effects of [[luck]]. R<sub>9</sub> variable may be either 0 or 0.50, depending on whether or not the attacking creatures gets "an unlucky strike". This is determined by combat variable luck, which may range from -3 to 3. Negative values can trigger unlucky strike to occur. The probability of such a strike is 1/12 (8.33%) if luck variable is -1, 1/6 (16.7%) for luck equal to -2, and 1/4 (25%) for luck equal to -3. Luck variable may be affected by artifacts, creature special abilities, adventure map locations, spells and the [[Luck (secondary skill)|Luck]] secondary skill.