Damage Mechanics

Introduction
A truly daunting load of mechanics can be found in the mechanics of damage calculations. This article will only go over the basics. If you need the damage mechanics of a particular skill, however, you will have to refer to the specific listing of that given skill in the skills section of mechanics. Any special rules or exceptions concerning damage will be listed on the particular skill listing they apply to.

With that said there's two general categories of damage calculations. There is weapon damage mechanics and skill damage mechanics. There do exist skills that make use of both the weapon damage and skill damage calculations within one skill and such skills will have this dual type calculation noted within their specific skill entries.

Nuts and Bolts

 * 0. First off is a generic note. After each stage of calculation if there is any decimal or fraction truncate it (also known as round down to the nearest integer or whole number). Each enumerated step is a stage of calculation. Steps 1 to 4 are simply for completeness in showing how the listed damage of a weapon is calculated.


 * 1) Obtain damage range of the base item of the weapon in question. This can be done by referring to this table.
 * 2) If the equipped weapon is ethereal then multiply base item damage 1.5.
 * 3) Increase the base item damage by x% which the sum of all enhanced damage % on the equipped weapon.
 * 4) Add all minimum and maximum damage on equipped weapon to the product of step 3. The equip mod description "Adds x-y damage" is +x minimum damage and +y maximum damage.
 * 5) Add all minimum and maximum damage gained from the rest of your gear, passive skills, auras, and states to the sum of step 4.
 * 6) Add together all sources of enhanced damage on equipped armor, equipped charms, passive skills (e.g. weapon mastery), auras, states, and the enhanced damage score of used attack skill. Increase the sum of step 5 by this sum of off weapon enhanced damage.
 * 7) Add elemental weapon damage to the product of step 6. This step in no way modifies the physical damage result of step 6. Elemental weapon damage on gear can be identified by "Adds x-y cold/lightning/fire/poison/magic damage". Elemental weapon damage bonuses from states are also included.
 * 8) +%elemental damage increases elemental weapon damage of its respective element if the attack is a melee hit. Example: 100-200 Fire damage granted by Enchant will be doubled to 200-400 if a zealer hits an enemy while having +100% fire damage from his gear, skills, and/or states. +%magic damage does not work in this manner unlike the other +%element boosts, because the default hardcoded magic mastery made by Blizzard is broken unlike the other 4 elements.
 * 9) All physical and elemental weapon damages are multiplied by final multiplier. In the case of most weapon attacks and normal attack this multiplier is 1. Refer to the notes on the skill actually being used to find out the correct weapon damage multiplier.
 * 10) All weapon related extra effects such as hit freezes target, deadly strike, crushing blow, etc are applied here.
 * 11) Deadly strike/critical strike doubles physical damage when the chance is made. Having more than 100% deadly strike is simply just the same as having 100% deadly strike.
 * 12) Hit slows target is inflicted automatically upon a successful hit. It slows the target for x seconds (original author unsure of exact number of frames of duration).
 * 13) Enemy is chilled for x frames where x is the chill duration attached to cold weapon damage of the attack.
 * 14) The chance for hit freezes target is rolled. If attack is a ranged attack this mod suffers a mod size penalty. Amount of hit freezes target, attacker level, and target level all play a role in chance to freeze target calculation as well as duration of freeze. Freeze state will override chill state.
 * 15) Open Wounds when the chance is made on striking inflicts a state that turns monster regen into a life drain for 200 frames. The amount of life drain per frame is based on attacker level.
 * 16) If the skill happens to have physical conversion to an other element then convert if necessary. The physical damage bonus from deadly strike is also converted.
 * 17) If there is knock back equipped from gear or states or if the particular skill includes knock back as an extra effect the attack hit will attempt to inflict knock back on the target. Certain monster types and champs/bosses can resist knock back. Some creatures and bosses are completely knock back immune.
 * 18) Crushing Blow inflicts a separate physical hit that is not subject to leech or thorns damage (such as iron maiden). It is only inflicted when the % chance is made. The fractions of remaining life crushing blow takes from the target depends on the type of target and are hard coded. Ranged attack crushing blows are hard coded to inflict half the damage of melee crushing blows. Crushing blow is subject to positive physical target resist as well as the monster life table (which determines monster health based on the number of players in game). In Aftermath patch 1.08 due to the values the monster life table the effectiveness of crushing blow is reduced to roughly 2/3rds the effectiveness it has on battle.net across the various players # settings.

Myths Section

 * 1) Myth : On weapon min and max damage is increased by on weapon enhanced damage. Reality : If this was so main steps 3 and 4 of the nuts and bolts section would be switched. All min and max physical weapon damage is applied after on weapon ED and ethereal damage bonuses.

Dual Type Damage Calculations
There is nothing particularly difficult about a dual type calculation. You just simply take the result of the weapon damage side and just add the result of the skill damage side on top of the weapon side. It's just simply adding the two sides together without an additional complex set of rules.

It should be noted that if both sides of a dual type attack contain poison damage the Poison Damage Stacking calculations are not a clean and simple addition.

Calculation Preface
While the weapon damage calculation is just merely a multistaged series of additions and multiplications with only one possible path the calculations can go... skill damage calculations on the other hand are in an entirely different league of complexity. The only thing skill damage calculations for the various skills even truly share in common is the base damage calculation from Skill Damage Tiers. While the element masteries may seem straight forward some strange stuff can go on. The psynergy calculation's potential insanity is best left for the actual breakdown.

The Nuts and Bolts of the Calculations

 * 0. When in doubt refer to the mechanics listing of the specific skill in question. The only thing that calculates the same way regardless of skill in question is base damage from the damage tiers based on soft skill level. For anything that is not the one iron clad thing just mentioned last sentence refer to the specific skill listing for all the specifics on damage calculation. If you aren't familiar with the Skill Damage Tiers read the article now to save yourself confusion with the first stage of of calculation. At the end of each calculation stage (each enumerated step) truncate decimals and fractions.


 * 1) Obtain the damage tier table for the specific skill you are calculating damage for. You will be plugging in values from this table and soft skill level.
 * 2) If soft level ranges from 1 to 8 : (skill base damage) = (lvl. 1 base damage) + ([tier 1 damage]*[skill level-1])
 * 3) If soft level ranges from 9 to 16 : (skill base damage) = (lvl. 1 base damage) + ([tier 1 damage]*7) + ([tier 2 damage]*[skill level-8])
 * 4) If soft level ranges from 17 to 22 : (skill base damage) = (lvl. 1 base damage) + ([tier 1 damage]*7) + ([tier 2 damage]*8) + ([tier 3 damage]*[skill level-16])
 * 5) If soft level ranges from 23 to 28 : (skill base damage) = (lvl. 1 base damage) + ([tier 1 damage]*7) + ([tier 2 damage]*8) + ([tier 3 damage]*6) + ([tier 4 damage]*[skill level-22])
 * 6) If soft level ranges from 29 to 100 (soft level cap) : (skill base damage) = (lvl. 1 base damage) + ([tier 1 damage]*7) + ([tier 2 damage]*8) + ([tier 3 damage]*6) + ([tier 4 damage]*6) + ([tier 5 damage]*[skill level-28])
 * 7) Increase the base damage calculated from step 1 by x% where x equals the sum of all pertaining element mastery states and +% element damage gear mods. While typically this means fire mastery/+%fire damage boosts a fire skill exceptions can exist. The author's notable exception would be a skill that existed in the Diablo II mod Median. This skill in Median was called exploding totem which dealt physical skill damage which for some strange reason was boosted by fire mastery as though fire mastery was physical skill damage mastery. There's also been cases where no elemental masteries apply to a skill at all even though it deals elemental damage. So when in doubt refer to the particular skill's listing.
 * 8) For the psynergy calculation just plain and simple refer to the skill listing's psynergy calculation section for the skill in question. While it tends be the simply Hard Skill Level psynergies one would be familiar with from battle.net as well as some Hard Stat points psynergies tacked on it isn't always this simple. What I'm about to speak of while unlikely to all happen to just one skill is entirely possible. Psynergies can be calculated on constants, the hard or soft levels of any skill, hard or soft stat values, current life, max life, current mana, max mana, character level, and any item/gear stat (whether its granted from gear or states) and all manners of additions, subtractions, multiplications, and divisions can be done between all these values. Furthermore functions calls such as diminishing returns or other things can be made to potentially further complicate the psynergy calculation. While psynergy calculations tend to be relatively simple for the most part nothing prevents them from being a massive overly complicated knotted wall of text that would make most cower away in dread.

Notes on Maximizing Damage
Sometimes the damage per hit value is not everything. How fast you deliver the blows is an other factor. An other major factor is enemy resists. In hell difficulty enemies tend to have very high resists even after having their immunities broken. Gear and skills to lower enemy resists can prove much more potent than just simply having a really high damage value on your character screen. - Baerk Konnevala 21:58, 19 December 2008 (UTC)