Difference between revisions of "Damage calculation"

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==Attribute Effect==
 
==Attribute Effect==
Listed weapon damage is done to a target with 60 armor when the attribute in the rank of the tied attribute equals the attribute requirement of the weapon (assuming both target and damage dealer are level 20), with any extra points in the attribute contributing to extra dealt damage. Also, as previously stated every 8 ranks in a physical damage attribute doubles the net damage caused by a noncaster weapon tied to that attribute (swords, axes, bows, spears, scythes, daggers, and hammers). Therefore, a max-damage scythe (9-41) with a requirement of 8 (very rare) should deal approximatly 18 to 82 damage with a rank of 16 in the approate attribute (in this case scythe mastery). Due to diminishing returns this is not the case, while it will do more than 9 -41, it will not be dealing double damage. Diminishing returns affect wepon attacks when the attribute rank exceeds the wepons requirement such that double damage is never achieved, but damage is slightly increased by each rank above the requirement. Due to attribute ranks above the required dealing extra damage, a lower requirement weapon will do more damage than a higher requirement weapon at the same attribute.
+
Listed weapon damage is done to a target with 60 armor when the attribute in the rank of the tied attribute equals the attribute requirement of the weapon (assuming both target and damage dealer are level 20), with any extra points in the attribute contributing to extra dealt damage. Also, as previously stated every 8 ranks in a physical damage attribute doubles the net damage caused by a noncaster weapon tied to that attribute (swords, axes, bows, spears, scythes, daggers, and hammers). Therefore, a max-damage scythe (9-41) with a requirement of 8 (very rare) should deal approximatly 18 to 82 damage with a rank of 16 in the approate attribute (in this case scythe mastery). Due to diminishing returns this is not the case, while it will do more than 9 -41, it will not be dealing double damage. Diminishing returns affect weapon attacks when the attribute rank exceeds the weapon's requirement such that double damage is never achieved, but damage is slightly increased by each rank above the requirement. Due to attribute ranks above the required dealing extra damage, a lower requirement weapon will do more damage than a higher requirement weapon at the same attribute.
   
 
==Illustrative Examples==
 
==Illustrative Examples==

Revision as of 03:31, 28 November 2006

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DISCLAIMER: The information in this article is based on experimental research conducted by the community, and may contain inaccuracies and speculation. While we strive for accuracy in these articles, we make no claims of experimental rigor or unbiased conclusions. Caveat lector.

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 specific 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.

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 × AE;

For damage 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).

Armor Effect

The Armor Effect (AE) depends on the difference of Effective Damage Rating(EffDR) and Effective Armor Rating (EffAR):

AE = 2(EffDR - EffAR)/40

Effective Damage Rating

The Effective Damage Rating (EffDR) is a simple sum of the Base Damage Rating (BaseDR) and any Damage Rating bonuses (DRBonus).

EffDR = BaseDR + DRBonus

For damage from spells and caster weapons (Staves, Wands, etc), the BaseDR is proportional to the attacker's level.

BaseDRcaster = 3 × Level

For "weaponry" damage (martial weapons and pets - those that have an attribute line for it), the BaseDR depends on the attacker's rank in the respective attribute of the "weapon".

BaseDRnoncaster = 5 × Rank

If the Rank of the linked attribute is greater than a threshold1 of Level/2+2, then there is a DRBonus of - 3 × [Rank - (Level/2+2)] (negative bonus), serving as a diminishing return. The square bracket term in this case rounds up (towards zero). This threshold only applies to "weaponry" damage, which results in a DRBonus of zero for non-critical hit attacks from spells and spellcasting weapons.

Expressed differently, the DR for non-caster damage is:

DRnoncaster = 5 × Rank;   if Rank <= Threshold
DRnoncaster = 5 × Threshold + 2 × (Rank-Threshold);   if Rank > Threshold
Threshold1 = Level /2 + 2

For traps, Damage Rating is same as for spells and caster weapons: 3 x Level.

For a detailed chart showing damage rating at each character level/rank, see Damage Rating progression.

Critical hits grant a DRBonus of 20.

1 The equation for the Threshold has only been confirmed for levels 1,8,11,14~16, and 18~20. The equation is interpolated to cover levels 2-7, 9, 10, 12, 13, and 17, and may not be accurate at those levels.

Armor Rating

The Effective Armor Rating depends on the Base Armor Rating (BaseAR), AR Shifter (ARShift), and Net Armor Penetration (NAP).

EffAR = BaseAR × (1 - NAP) + ARShift

Each attack randomly hits one of the various body locations. The probablity of hitting each location is generally believed to be proportional to the relative armor costs for the same level of armor. If that were true, the probablities would be:

  • Chest - 3/8
  • Legs - 2/8
  • Head - 1/8
  • Hands - 1/8
  • Feet - 1/8

However, it is also believed that certain attack skills and spells have a bias towards certain body parts, so they are more likely to hit them. Relative positioning of the attacker and target may also affect which part is more likely to be hit.

The Armor Rating of the piece corresponding to the location attacked is used as the BaseAR, while any bonuses on that armor contributes to ARShift. Certain armor are described as having a negative bonus of Holy Damage you receive is increased by 5, which function regardless of hit location and stacking.

Primary and secondary weapons, as well as skills, may also modify the armor value. They are added to the ARShift regardless of which body location was hit.

Armor penetration can come from the Warrior's Strength attribute, weapon upgrades, or skill properties. Some of them simply have x% armor penetration, whereas others provide +y% armor penetration. Pick the highest x (if none, use 0), and add all the y's to it to obtain the net armor penetration (NAP). Note that NAP is a real number between 0 and 1; remember to divide percentage values by 100 (20% → 0.2, etc.).


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 × DScale× AE ] + DShift) × DMult] + DNeg

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

Damage Modifiers

Modifier Stack by How to identify Examples
Notes
Damage
Scaler
(DScale)
Multiplication Percent modification of damage
  • DScale from weapon bonuses only affect the weapon's base damage
Damage
Shifter
(DShift)
Addition fixed amount of + or - damage
  • While "+x damage" is a damage modifier, "x additional damage" is NOT a damage modifier. The latter is a separate damage.
  • Shielding Hands does not count as DShift.
Damage
Multiplier
(DMult)
Multiplication "Double" or "Half"
Damage
Negator
(DNeg)
Addition gets healed instead of taking damage
  • The skill functions as "Up to x damage gets canceled, and target is healed for same amount as the canceled damage".
  • The healing effect is not part of the damage calculation.

DScale, and DMult are by default 1; whereas DShift and DNegate are by default 0.


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.

Notes

Every 8 ranks in a physical damage attribute thus doubles the net noncaster damage caused; similarly, every 13 character levels doubles caster damage. The accounting per rank or level is as follows: every rank in attack attributes scales the damage by exactly a factor of 2(1/8)

(roughly 9%), and every character level scales the caster damage by 23/40 (roughly 5.33%). Note that the effect of cumulative ranks or levels is compounded; for example, 5 ranks in an attack attribute doesn't increase damage by 45%, but by (1.095 - 1) × 100 ≈ 53%.

It is important to keep in mind that certain skills such as Greater Conflagration and Judge's Insight change the damage type, and therefore can have an effect on AR bonuses or DR calculation. The articles on these skills explain their damage type changes in more detail. Only in the early PvE game, advanced PvE areas, or in exceptional situations is the EffectiveAR actually less than the EffectiveDR, so the AE generally always reduces the effective damage. The philosophy behind the AE scale can be seen as follows: in the prototypical case where the attacker and target are roughly equal PvP players, the attacker's ranked 12 noncaster attack or normal caster attack at character level 20 will exactly negate the target's EffectiveAR of 60 (standard for all spellcaster PvP armor).

The AE equation gives us a handy rule of thumb: every 40 increase (decrease) in EffectiveAR halves (doubles) the amount of normal damage (i.e., damage not caused by armor ignoring attacks). A Warrior with 100 armor against physical damage being whacked by a sword will take half as much damage as any 60 armor Elementalist being whacked by the same sword. Skills such as Healing Signet temporarily reduce AR by 40, which translates to double damage for normal attacks. An increase of approximately 16 armor would correspond to taking 75% damage. (Many ranger armors such as Drakescale or Frostbound Armor give AR bonuses of +15.)


Handy Simplification:

eAR = (Your Current AR - 60)

1 / (2^(eAL/40)) = ~Damage Taken %


Consider a Mesmer, an Elementalist, and a Ranger being hit by the same attribute level 16, caster level 20 Fireball. The Mesmer with only 60 armor takes all 119 damage. The Elementalist has Pyromancer's Armor with 75 armor against fire and takes 92. The Ranger wears Druid's Armor which has 100 armor against elemental damage so he takes 60 damage.

Attribute Effect

Listed weapon damage is done to a target with 60 armor when the attribute in the rank of the tied attribute equals the attribute requirement of the weapon (assuming both target and damage dealer are level 20), with any extra points in the attribute contributing to extra dealt damage. Also, as previously stated every 8 ranks in a physical damage attribute doubles the net damage caused by a noncaster weapon tied to that attribute (swords, axes, bows, spears, scythes, daggers, and hammers). Therefore, a max-damage scythe (9-41) with a requirement of 8 (very rare) should deal approximatly 18 to 82 damage with a rank of 16 in the approate attribute (in this case scythe mastery). Due to diminishing returns this is not the case, while it will do more than 9 -41, it will not be dealing double damage. Diminishing returns affect weapon attacks when the attribute rank exceeds the weapon's requirement such that double damage is never achieved, but damage is slightly increased by each rank above the requirement. Due to attribute ranks above the required dealing extra damage, a lower requirement weapon will do more damage than a higher requirement weapon at the same attribute.

Illustrative Examples

Related Articles

Original References

The present article is built on the results of the research laid out in the original unannotated version of the following article, with additional original research conducted by users of the GuildWiki.