Damage calculation

Damage in Guild Wars results from actions taken by attackers that subtract a portion of a defender's health. This definition includes many attacks or skills (including spells) but does not include health degeneration, life stealing, sacrifice, or health reduction caused by skills such as Infuse Health or Illusion of Weakness.

When an attacker attempts to damage a target, the following is factored in:
 * The damage type, such as Fire or Blunt. The amount of damage done may vary due to the defender's armor and resistances to that damage type.
 * The attacker's ability to inflict the damage.
 * The target's ability to resist this damage.
 * Bonuses on both sides. An attacker may have bonuses that augment the damage and the target may have bonuses that reduce the damage.

Damage Types
There are many individual damage types, and two meaningful damage type categories, Elemental and Physical.
 * 1Damage of these types are only available from skills. Skills dealing these types of damages ignore armor (see exception below).
 * 2Earth damage from Dust Trap ignores armor and ignores Winter's effect on elemental damage.
 * 3Piercing damage from Whirling Defense ignores armor and ignores Greater Conflagration's effect on physical damage.
 * 4Judge's Insight is the sole exception where Holy Damage does not ignore armor.

Alternativelly, you can refer to this diagram for damage types grouping:



A Simplified Damage Calculation
''Note: For simplicity, on this page the term attack describes any attempt to damage an opponent. However, whenever the word "attack" is used in skill descriptions, it refers to the attack action.''

There are many different factors to consider while calculating damage. To avoid confusion, this section presents a simplified damage calculation which only takes into consideration the more common factors.

The Approximate Damage (ApproxD) depends on the Raw Damage (RD) and the Armor Effect (AE).
 * '''ApproxD = RD &times; AE;

For attacks that ignore armor, AE is set to 1.

Raw Damage
Skill-based offense (like Shock) have a specific raw damage (RD) value indicated in the skill description.

Weapons attacks select RD each time uniformly from the damage range of the weapon. For weapons that have an attribute requirement on their damage range, there is actually another hidden range used for when the attacker does not meet the requirement (see here for details).

Effective Damage
The Effective Damage (ED) considers all the Damage Modifiers that were dropped when calculating the Approximate Damage. The ED depends on the Raw Damage (RD), various Damage Modifiers (D*), and the Armor Effect (AE).


 * ED = [([RD &times; DScale&times; AE ] + DShift) &times; DMult] + DNeg

Again, for attacks that ignore armor, AE is set to 1, essentially removing it from the equation.

Damage Cap and Redirection
Certain enchantments will restrict the maximum damage the target can receive, or redirect some of the damage away from the target, thus making the received damage less than the Effective Damage. Redirection is always applied before the cap.

Related Articles

 * Spike damage
 * Damage over time
 * Point Blank Area of Effect
 * Area of Effect

Original References
The present article is built on the results of the research laid out in the following article, with additional original research conducted by users of the GuildWiki.
 * SonOfRah's damage article