Damage calculation

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This page describes the mechanics of damage calculation, and may be particularly useful for players who want to spade out values for various effects related to damage. This is important for skill coefficients and other values which may not be documented in-game.

Skill damage[edit]

Weapon skill[edit]

Damage = (Weapon strength * Power * Skill coefficient) / Armor
  • Weapon strength: A uniformly distributed random number taken from within the range listed as "Weapon Strength" on the equipped weapon. The weapon damage used for a skill will typically be that of the weapon associated with that skill; utility and elite skills are typically not affected by weapon damage and use a range based on the player's level.
  • Power: The current power as listed on the Hero tab.
  • Skill coefficient: Every skill has a damage coefficient used to calculate damage inflicted.
  • Armor: The target's current armor as listed on the Hero tab. Armor is the sum of defense and toughness.


Power is the primary attribute for calculating how much damage is dealt. Power can be increased through equipment, the might boon, and various effects that provide bonuses to power, such as consumables. The base power attribute for a level 80 character is 1000.

Weapon strength[edit]

Weapon strength is a factor of damage calculation for weapon skills. The weapon strength on each weapon is given as a range of values and is affected by the type, level, and rarity of the weapon. Whenever a weapon skill deals damage, a value is chosen at random from the range of weapon strength on the equipped weapon. When a damage value is displayed in skill tooltips, the midpoint of the range is used to calculate the displayed value.

Values for ascended weapons
Weapon Weapon strength Midpoint
Main hand
Axe 900 - 1100 1000
Dagger 970 - 1030 1000
Mace 940 - 1060 1000
Pistol 920 - 1080 1000
Scepter 940 - 1060 1000
Sword 950 - 1050 1000
Focus 873 - 927 900
Shield 846 - 954 900
Torch 828 - 972 900
Warhorn 855 - 945 900
Greatsword 1045 - 1155 1100
Hammer 1034 - 1166 1100
Longbow 966 - 1134 1050
Rifle 1035 - 1265 1150
Shortbow 950 - 1050 1000
Staff 1034 - 1166 1100
Harpoon gun 950 - 1050 1000
Spear 950 - 1050 1000
Trident 950 - 1050 1000

Other sources for weapon strength values[edit]

The values above apply to weapon skills, other types of skills may use different weapon strengths:

  • Profession mechanics such as Engineer's tool belt skills will typically use the currently equipped main-hand weapon in calculations.
  • Transforms such as Death Shroud have their own unique weapon strengths, that can vary between game modes. Tooltips for transform skills are frequently incorrect, making the true weapon strength difficult to verify.
  • Kits and conjures use a standardised weapon strength that is dependent on the equipped main-hand weapon's rarity. In PvE, exotic weapons yield a midpoint of 922.5 and ascended weapons yield a midpoint of 968.5.
  • Utility skills, and skills triggered by traits or runes/sigils use a base weapon strength with a midpoint of 690.5 and a variance of 35.

In addition, entities spawned by skills such as turrets, minions or illusions have their own weapon strength and may or may not scale with the player's own stats.


Armor is calculated as the sum of the toughness attribute and the defense value. The defense rating is the sum of all the defense values provided by armor and any equipped shield. Trinket slots do not provide defense, although they can provide a bonus to toughness. The profession determines whether the player can wear heavy, medium, or light armor, where heavy armor provides the most defense and light armor provides the least defense.

Defense values for ascended armor
Armor piece Light Medium Heavy
Helmet 77 102 127
Shoulders 77 102 127
Chest 330 355 381
Gauntlets 140 165 191
Leggings 203 229 254
Boots 140 165 191
Total 967 1118 1271

Condition damage[edit]

Condition damage is displayed in the skill tooltip. The value is handled in {{skill fact}} and does not require users to enter the values manually. The values below are valid in PvE:

Condition Stacking Formula
Bleeding.png Bleeding Intensity 0.06 * Condition Damage + 0.25 * Level + 2
Burning.png Burning Intensity 0.155 * Condition Damage + 1.55 * Level + 7
Poisoned.png Poisoned Intensity 0.06 * Condition Damage + 0.375 * Level + 3.5
Confusion.png Confusion Intensity
On Skill Use
0.1 * Level + 2
0.195 * Condition Damage + 1.15 * Level + 3.5
Torment.png Torment Intensity
While Not Moving
0.06 * Condition Damage + 0.25 * Level + 2
0.09 * Condition Damage + 0.36 * Level + 3

Damage calculation[edit]

The formula for damage inflicted on a target can be generalized to damage modifiers that increase the amount of damage inflicted or decrease the amount of damage received.

Damage = (Skill damage * Positive multipliers) / (Armor * Negative multipliers)

The majority of damage multipliers combine in a multiplicative fashion rather than additive; i.e. they stack on top of each other instead of being calculated separately. However, some sigils, traits, and effects from utility skills stack additively with each other. For example, a Superior Sigil of Force (5%), a slaying Sigil (3%), an additive 10% trait, a multiplicative 20% trait and the (6) bonus of the Superior Rune of the Scholar (5%) combine for a final damage bonus of (1 + 0.05 + 0.03 + 0.1) * 1.2 * 1.05 = 1.4868 or approximately 48.7%.

Examples of positive multiplier[edit]

Examples of negative multiplier[edit]


Damage coefficient[edit]

In an ideal world skill tooltips will match the damage a skill actually deals, but there are multiple instances where this is not the case. You may therefore wish to calculate skill coefficients yourself using the damage equation. We have many variables, but fortunately there are tools for getting constant values. Players can test skills in the Heart of the Mists area for PvP, or the Special Forces Training Area for PvE.

In PvP the power value can be fixed by unequipping all equipment that provides attribute bonuses. The power for a level 80 player with no equipment is 1000. The weapon strength values are given by the weapon type that is equipped and are equivalent to a level 78 exotic weapon found in PvE. The armor value of the foe we are using the skill on is needed. Fortunately, the testing dummies in Hall of Memories are suitable punching bags, but we need to know how much armor they have.

Golem Armor
Target Golem - Heavy 2597
Target Golem - Medium 2322
Target Golem - Light 2185

The Golem in the Special Forces Training Area also has an armor value of 2597.

We will use the heavy golem for our calculations, as tooltips assume this value for their calculations. Before testing we need to make sure no positive or negative multipliers are in effect (or be aware of those that are). You may want to attempt to minimise your crit chance as tooltips assume the attack is not a critical hit.

We can now use the equation to calculate the skill coefficient based on the damage inflicted by the weapon skill based on the type of weapon. Our formula will look like:

Damage = Weapon strength * power * Skill coefficient / 2597

We can then solve the equation for the skill coefficient given the damage, after looking up the weapon strength of the weapon type:

Skill coefficient = 2597 * Damage / (Weapon strength * power)

By comparing the damage you deal against the minimum and maximum values for the weapon strength, you can verify whether or not the tooltip gives the correct information.


  • Skill - An attack or action that inflicts one or more effects.
  • Effect - A mechanic that modifies the state of a player or NPC.
  • Damage - Any effect from a skill that reduces the amount of health of a target.
    • Direct damage - A skill effect that reduces the amount of health of the target as a function of the power stat.
    • Condition damage - A skill effect that reduces the amount of health of the target as a function of the condition damage stat.
  • Weapon - A piece of equipment that gives access to weapon skills.
    • Damage range - The range of damage on a weapon. The damage is equally distributed random function between a minimum and maximum damage value.
    • Weapon strength - The average damage inflicted by a weapon; the average value of the minimum and maximum damage.
  • Power - An attribute that increases the amount of direct damage inflicted by an effect.
  • Armor (attribute) - An attribute calculated as the sum of defense and toughness
  • Defense (attribute) - The sum of defense rating for all pieces of armor equipped.
  • Toughness - An attribute that decreases the amount of direct damage received by an effect.