Diablo II: Resurrected

Calculate your real damage output against enemy resistances in D2R. Factor in monster immunities, Conviction, Lower Resist, sunder charms, Amplify Damage, Cold Mastery, and −% enemy resistance from gear to see actual damage dealt.

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D2R Resistance & Damage Calculator

Enter a monster's resistance and all of your resistance-reduction — sunder charms, Conviction, Lower Resist, Amplify Damage, Cold Mastery, and −% enemy resistance from gear — to see whether you break the immunity and exactly how much damage you actually deal. Models the real D2R 1/5 immunity-breaking rule.

Damage Type

Your Setup

Monster & Damage

Target preset

Act-boss values are exact Hell resistances; scenarios are generic tiers.

Monster Lightning Resistance

100% or higher = immune. Editing this switches to Custom.

Champion / Unique enchantment

Boss-pack mods add resist to one element and can create a second immunity.

Skill Damage (min)

Skill Damage (max)

Use your skill's listed damage (e.g. the tooltip range).

Resistance Reduction

Lightning Sunder charm equippedSets immune monsters to 95% resist; other −resist then applies at 1/5 (gear/facets stay full).

Conviction aura −resist

Conviction aura: −30% (slvl 1) to −150% (very high slvl). Read your aura tooltip.

Lower Resist curse −resist

Lower Resist curse: −31% (slvl 1) to −70% (slvl 20+). Read your curse tooltip.

−% Enemy Resist (gear / facets / pierce)

Sunder Cleft, Death's Web, facets, etc. Full effectiveness — but does nothing while the monster is still immune.

Effective Lightning Resistance

110%

Monster takes no damage

Damage Output

−100% — immune, no damage gets through

How this was calculated

Immunity NOT broken: 110% − 0/5 = 110% (still ≥ 100%).
Immunity-breaking effects (Conviction / Lower Resist / Amp / Decrepify) count at 1/5× because the monster started immune.

How Resistance & Immunity Work in D2R

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Immunity & the Damage Formula

A monster with over 99% resistance (100%+) is immune and takes no damage until its resistance drops below 100%. Otherwise damage scales linearly: damage × (1 − resist ÷ 100). The floor is −100% resist, which doubles damage taken.

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Breaking Immunities (1/5 Rule)

Only Conviction and Lower Resist (elemental), and Amplify Damage and Decrepify (physical) can break immunities — at 1/5 effectiveness. That 1/5 penalty always applies if the monster started immune, even after it's broken.

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Sunder Charms

A sunder charm sets an immune monster's resistance to 95%. After sundering, Conviction, Lower Resist, and Cold Mastery apply at 1/5, while gear and facet −enemy resist applies at full. Holder-only, with a large penalty to your own resistance.

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−% Enemy Resistance & Cold Mastery

−% enemy resist from gear, facets, and pierce does nothing while a monster is still immune — it only counts once immunity is broken, then at full. Cold Mastery can't break immunity and drops to 1/5 once immunity is broken by another source.

Frequently Asked Questions

What counts as an immune monster?

A monster with more than 99% resistance (100% or higher) to a damage type is immune and takes zero damage from it until its resistance is reduced below 100%. The lowest any monster resistance can reach is −100%, which doubles the damage it takes.

How do I break an immunity?

Only four effects break immunities: Conviction and Lower Resist for elemental, Amplify Damage and Decrepify for physical. Against an immune monster they work at only 1/5 of their listed value. Example: a monster at 110% lightning resist with a level-20 Conviction (−85%) → 110 − 85/5 = 110 − 17 = 93%, immunity broken. That 1/5 penalty stays in effect for these skills any time the monster started immune.

How do sunder charms change the math?

Holding the matching sunder charm sets an immune monster's resistance to 95% (breaking the immunity). After that, Conviction, Lower Resist, and Cold Mastery apply at 1/5, but −% enemy resistance from gear and facets applies at full. The sunder only works for the character wearing the charm, and it applies a large negative to your own resistance of that element.

Why isn't my −enemy resist from gear doing anything?

−% enemy resistance from gear, facets, and pierce does nothing while a monster is still immune. It only applies once the immunity is broken by another source — a sunder charm, Conviction, Lower Resist, Amplify Damage, or Decrepify — or against monsters that were never immune. Once it applies, it's at full effectiveness.

What about champion and unique (boss) packs?

Champion and unique monsters can spawn with an enchantment that adds resistance to one element: Stone Skin gives +100% physical in Hell (physical immune), and Fire / Cold / Lightning Enchanted each give +75% to that element. That means a pack can become immune to an element the base monster isn't — a Lightning Enchanted unique of a 40% lightning monster hits 115% and turns lightning immune. Use the "Champion / Unique enchantment" dropdown to add this. A unique can hold at most two immunities; the game blocks a third.

Does Cold Mastery break cold immunities?

No. Cold Mastery cannot break an immunity by itself. Against non-immune cold monsters it applies at full value; once a cold immunity is broken by another source (sunder, Conviction, or Lower Resist), Cold Mastery applies at 1/5.

How much damage does resistance actually remove?

Each 1% of resistance removes 1% of that damage type. Damage dealt = your damage × (1 − resist ÷ 100). 75% resist → 25% damage; 0% resist → full damage; −100% resist → double damage.