Path of Idle attributes: the formulas that decide your damage

Three formulas explain almost every attribute decision in this game. Defense, crit chance and dodge chance all resolve as value divided by value plus a threshold that grows with your own level. Resistance uses 100 divided by 100 plus the resistance value. Skill speed multiplies as 100 plus your combined speed, over 100.

Everything below follows from those three shapes. The combat rate calculator runs them on your actual numbers, and every one of the 56 attribute pages carries its own.

Attack and Damage are different things

Physical Attack and Elemental Attack determine the power of most Physical and Elemental skills. They are flat values and they are the base your damage is built on.

Blunt, Slash, Pierce, Fire, Frost and Lightning Damage are percentage increases to that damage type. Martial Damage and Spell Damage are percentage increases by skill tag, and Base, Mastery and Utility Skill Damage are percentage increases by compendium category.

So an item that gives Physical Attack raises the base, and an item that gives Slash Damage raises a multiplier on part of it. Which is worth more depends on which side you are short of, and a build that has stacked one and ignored the other is usually the one with a disappointing damage number.

The three primary attributes feed the bases directly. Strength gives Physical Attack and Physical Defense. Intelligence gives Elemental Attack and Elemental Defense. Dexterity gives Crit and Dodge.

Crit, dodge and defense get worse as you level

All three use the same shape:

chance = value ÷ (value + threshold)

The threshold comes from your hero’s level. It is 1,260 at level 20, 2,490 at level 40, 3,940 at level 60, 5,610 at level 80, and 7,500 at level 100. The attribute descriptions say “effect scales with your level” and this is what that means: the same number gets weaker as the hero grows.

Crit damage is 2 plus your crit chance, plus any bonus. So at 50% crit chance the multiplier is 2.5x, and pushing crit from 50% to 64% only moves the multiplier from 2.50 to 2.64. Past the halfway point, Crit Value is one of the weaker things you can put on an item.

Dodge takes one extra step. The attacker’s Accuracy strips a percentage off your dodge before the formula runs:

effective dodge = dodge value × (100 − accuracy) ÷ 100

Martial Accuracy and Spell Accuracy each ignore a percentage of the target’s Dodge Value, capped at 100%. For triggered damage, the two are summed. This is why a dodge tank can look fine in one fight and evaporate in another.

Resistance does not have this problem

Resistance is flat and level independent:

damage taken = 100 ÷ (100 + resistance)

100 points of a resistance halves that damage type at level 20 and at level 100 alike. Defense does not: the same defense value is worth much less at high level because its threshold has grown.

The practical rule follows: as your heroes level, shift defensive budget from Defense toward Resistance. This matters most in Outlands and Doom, where the encounter attribute level runs up to 20 points ahead of the enemy level.

Speed and cost

Skill speed affects both cast speed and cooldown. Applicable speed values are combined first, then applied:

speed multiplier = (100 + combined speed) ÷ 100, and adjusted cooldown = base cooldown ÷ multiplier

Only speeds that apply to the skill count. Martial Speed does nothing for a Spell, and a skill that is neither Martial nor Spell uses a runtime default instead of your typed speed.

Cost reductions are diminishing rather than additive, which is why stacking cost reduction stops helping quickly. If your problem is running out of mana, the mana guide works through the actual fixes.

What your summons inherit

This decides whether a summon build works. Exactly 20 attributes are inherited by allies and minions:

Physical Attack, Elemental Attack, Physical Defense, Elemental Defense, Health, Health Regen, Crit Value, Dodge Value, the six damage types, and the six resistances.

Thirty six are not, including Strength, Dexterity, Intelligence, Martial Damage, Spell Damage, every skill speed, every cost reduction, Healing Power, Shield Power, Buff Effect, Health Tenacity and Crit Resistance.

Read that list twice if you are building around the Hunter’s Frost Wolf Ally, the Mercenary’s Ballista Sentry, or the Warrior’s minions. Stacking Martial Damage on a summoner does nothing for the summons. Stacking Physical Attack, Crit Value and the matching damage type does.

Note also that the primary attributes themselves are not inherited, only their outputs. A summoner benefits from Strength through the Physical Attack it produces, not directly.

Attributes people misread

Healing Power increases healing you apply, and explicitly does not affect Health Regen or Health on Kill. If your sustain comes from regen, Healing Power is a dead stat.

Shield Power increases shield amounts and does not affect Shield Decay. Those are two different problems: how big the shield is, and how fast it drains.

Health Tenacity halves the rate at which health below a threshold percentage is deducted, up to 100%. It is a low health survival stat, not general mitigation.

Crit Resistance reduces the chance to be crit, capped at 100%, and is separate from resistances by damage type.

Mana Reservation and Health Reservation reduce how much a reservation effect takes, and use the diminishing formula rather than subtracting directly.