Ability damage and healing

An ability’s damage lives in the game files as a base value quoted at ability power 100 and item power 0. Two things multiply it: the weapon’s own ability power, and how far that weapon’s item power has grown.

shown = base × abilityPower / 100 × abilityProgression^(itemPower / 100)

@abilitypower is a property of the item: 100 on every armor piece, 120 on most staves and bows, 138 on a broadsword. @abilitypowerprogression comes from the item’s row in the progression table: 1.0825 for one-handed weapons, 1.0918 for two-handed weapons and armor.

What scales and what does not

Anything that is an amount of health or energy scales: direct damage, damage over time, healing, what a shield absorbs, energy an ability gives back.

Counts, intervals, radii, chances and percentage buffs do not. Neither does a change the files mark as relative to the target. @changetype="relativemax" makes the number a fraction of maximum health, so Levitate’s 0.075 is 7.5% however powerful the weapon.

Worked example

Blade Cyclone, base 40, on a Broadsword (ability power 138, one-handed):

at 700 IP:   40 × 1.38 × 1.0825^7   = 40 × 1.38 × 1.742  =  96
at 1100 IP:  40 × 1.38 × 1.0825^11  = 40 × 1.38 × 2.384  = 132

Healing is the same multiplier, raised to a power

A weapon that triples an ability’s damage does not triple its healing:

heal = base × (abilityPower / 100 × abilityProgression^(itemPower / 100)) ^ 0.663445601

The exponent is AbilityPowerProgression.@hitpointprogression. Its name reads like a share, since it and @resistanceprogression add up to exactly 1, but it behaves as an exponent, and reading it as a share is what hid it for so long.

Blood Bandit, self-heal 50 at the base, on a Battleaxe (ability power 138, one-handed):

at 700 IP:   damage ×2.404  →  heal ×2.404^0.6634 = ×1.789   50 × 1.789 =  89
at 1100 IP:  damage ×3.300  →  heal ×3.300^0.6634 = ×2.208   50 × 2.208 = 110

Verified

Ten numbers across two abilities and three item powers: Blood Bandit’s full charge table off an Adept’s Battleaxe at 700 (89 / 143 / 197 / 268) and an Elder’s at 1100 (110 / 177 / 243 / 331), Desperate Prayer’s two branches off a Master’s Holy Staff at 900 (181 / 399), and Sacred Pulse off an Elder’s Great Holy Staff at 1100 (201).

Only restored health takes the exponent. Damage, energy gains and what a shield absorbs still use the plain multiplier.

Carrying capacity is that multiplier raised to a different power

The dump holds a share, not kilograms:

kg = share × 25 × (abilityPower / 100 × abilityProgression^(itemPower / 100)) ^ 2.264101591 − 25 × share

Both constants sit in AbilityPowerProgression beside the healing exponent: @baseload is 25 and @loadprogression is 2.264101591. That second number is chosen so the growth lands on exactly 1.22 per 100 item power on a slot whose ability progression is 1.0918, 1.0918^2.264101591 = 1.220000.

The − 25 × share at the end matters: capacity is what the item adds over an empty one, so the curve bends and a plain exponential misses the low tiers by several kilograms.

Shoes carry a share of 0.3, bags 1:

shoes at 500 IP:   0.3 × 25 × (1.22^5  − 1) = 13 kg
shoes at 1100 IP:  0.3 × 25 × (1.22^11 − 1) = 59 kg
bag at 900 IP:     1   × 25 × (1.22^9  − 1) = 125 kg

Verified

Eight tooltips: shoes at 500, 600, 700, 800, 1000 and 1100 item power (13, 17, 23, 29, 47, 59 kg) and bags at 600 and 900 (57 and 125). The kilograms depend on the item’s own item power and nothing else in the loadout, checked in game.

Combat fame: the item-power factor becomes an exponent

The Satchel of Insight’s fame bonus is the one formula on this wiki that does not multiply by the item-power factor. It raises a constant to it:

f    = abilityProgression^(itemPower / 100)
Fame = fameeffconst + fameeffbase^(f − 1) − 1

Both constants come from CombatFameToSilverConversion in gamedata.json: today @fameeffbase is 1.23998 and @fameeffconst 0.1996.

How it was found

Three balance patches moved those constants, and each published the numbers before and after. The dumps repository keeps every version of the game files, so the constants and the tooltips can be lined up:

The January 2021 patch changed only fameeffconst, and the bonus moved by exactly 100 × Δconst at every item power, so the constant is a plain additive percentage. That left one unknown curve. Inverting the formula for the exponent gave the same numbers in all three eras, and its steps grew at 1.0918 per 100 item power, the bag’s own ability progression. The exponent is f − 1.

Verified

All fifteen published values, across three eras, to the last digit, including 88.246 % at item power 1400, which no measurement of ours ever covered.

The silver cost on the same buff is still unexplained: the constants have not moved since 2021 but the cost has gone 1.25 → 1.45, so something outside that node scales it. The wiki quotes measured values for it and leaves the rest blank.

Auto-attacks

The weapon’s own auto-attack uses the same shape with @attackdamageprogression and no per-item multiplier. Damage per second is the unrounded damage times the swing rate: the Broadsword’s 57.5 × 1.35 reads 78/s, not the 77 the displayed 57 would give.

Verified

Blade Cyclone at 700 and 1100 item power (96 and 132), Arcane Orb off a staff with ability power 120 (153 and 210), and auto-attacks on both a one-handed Broadsword (57 → 79) and a two-handed axe (147, 118/s).