I’d like a clarification on the damage calculation for skills. Am I understanding it correctly that it goes like: Net Damage = ([Base Damage * Sum of Increased Damage Modifiers] * Product of More Damage Modifiers)
Base_Damage: The primary damage of the skill. This is either specified in the skill itself (and increases with the level of the skill gem), or is determined by the damage of your weapon (in the case of most Attacks).
Added_Damage: Additional flat damage applied, modified by the skill’s damage effectiveness value.
Increased_Damage: Additional percentage damage applied. All applicable sources of increased damage stack additively (e.g. two +10% increased damage modifiers add together to make 20% increased damage: 100% + 10% + 10% = 120%).
More_Damage: Additional percentage damage applied. All unique sources of more damage are multiplicative with each other (e.g. two +10% more damage modifiers will multiply on top of each other: 110% * 110% = 121%).
Hit_Rate: The rate at which the damage is applied, typically based on attack speed or cast speed.
Critical_Strike_Damage: See Critical Strike Multiplier.
Critical_Strike_Chance: See Critical Strike Chance.
In general:, More Damage is usually more effective than Increased Damage, due to diminishing returns from stacking increased damage modifiers, and the multiplicative nature of More Damage modifiers.
Damage source
All sources of damage are encompassed by one of four categories:
Attack damage
Spell damage
Secondary damage
Damage over time
A single hit or instance of damage can only be one of these four categories at a time and are mutually exclusive. Modifiers which apply specifically to one damage source never innately apply to any others, though some skill modifiers allow the numeric values of one damage source to be used in calculations for another (e.g. Vortex – note that in this example, the damage over time component is still not considered dealing spell damage, and will not be affected by modifiers to spell damage taken, such as Unnerve). Generic modifiers (e.g. Elemental Damage or simply just “Damage”) can affect multiple damage sources.
Damage type
A hit can be composed of several types of damage, but each damage type is calculated separately, including damage range rolls. Currently there are five types of damage:
Physical damage – Considered the default damage type. Auto-attacks typically deal physical damage before conversion, and almost all weapons (and unarmed) have base physical damage. Physical damage over time can be inflicted with the bleed ailment, or another common debuff, Corrupted Blood.
Fire damage – One of three elemental damage types. Dealing a critical strike with fire damage inflicts ignite. Fire damage over time from ignites, burning ground, or other sources is often also classified as burning damage.
Cold damage – One of three elemental damage types. Hitting an enemy with cold damage can inflict the chill ailment, while dealing a critical strike with cold damage can inflict freeze. Cold damage over time can be inflicted by certain spells, typically also applying Chill.
Lightning damage – One of three elemental damage types. Dealing a critical strike with lightning damage can inflict shock. Base lightning damage tends to have higher variability in damage ranges, with minimum and maximum damage values often being significantly further apart than similar fire or cold damage modifiers. Lightning damage over time is significantly less common than its counterparts, mostly limited to Mana Siphoner, Shock and Horror’s beam skill, and some environmental hazards.
Chaos damage – Considered the rarest damage type, chaos damage bypasses energy shield and damages life directly. Chaos damage has the benefit of not being reflectable. Chaos damage over time can be inflicted with the poison ailment. Many chaos skills also innately cause debuffs that deal chaos damage over time.