How Deadlock Damage Actually Works: Gun, Spirit, Resist and Headshot Math

The number on a Deadlock tooltip is a starting point. What a hit really does depends on your stats, how far away you are, where you land it, and what the target is wearing. This guide explains the pieces and how they combine, so you can compare builds with real numbers.

Updated October 2026. The formulas below come from community documentation (the Deadlock Wiki and deadlock.io), because Valve doesn't publish them. Item values, ability numbers and coefficients change nearly every patch, so the Deadlock Damage Calculator asks you for those and only hard-codes the rules.

Gun damage and ability damage are different systems

The biggest mistake in older build math, including an earlier version of our own calculator, was treating everything as "spirit % × weapon %". They are separate:

Gun damage scales with weapon damage bonuses.
Ability damage scales with Spirit Power.

Investing in one does nothing for the other, which is why the stat scaling tool now reports bullet and ability results side by side.

Gun damage

[(Base × (1 + Weapon%)) + Flat] × Falloff × (1 − Resist) × Headshot × (1 + Bullet amp)

Weapon damage % scales the base bullet damage only. Multiple sources add together before scaling.
Flat bonuses are added after that step, so a weapon % bonus doesn't make them bigger. Everything after still applies to them: falloff, resist, headshots and amps.
Falloff drops damage linearly from 100% down to 10% across your hero's falloff range. Fighting at the edge of range cuts damage to a fraction, which often matters more than a single item.
Headshots multiply damage by 1.65× by default. The exact formula is 1 + (0.65 + hero modifier) × crit resist. Some heroes get less: for example Baba, Billy, Rem and Violet −20 (1.45×), Celeste and Kelvin −25, Doorman and Vyper −30, Nurse Harrow −40 and Drifter −45 (1.2×). A few abilities use their own crit values, and some heroes can't headshot for extra damage at all.
"Increased bullet damage" debuffs on the target apply at the very end.

Ability (spirit) damage

(Base + Spirit Power × Coefficient) × (1 − Spirit resist) × Amps

Every ability has a coefficient, shown as the "x0.8"-style number beside the spirit icon. Spirit damage is flat per point of Spirit Power. For example, an ability with 65 base damage and a 0.8 coefficient deals 81 at 20 Spirit Power.

This means the same Spirit Power is worth far more on a high-coefficient ability than a low one, so ask which abilities you cast before you buy. Percent bonuses to Spirit Power (like Boundless Spirit) multiply together and raise your Spirit Power figure itself. Tooltips round coefficients to one decimal, so test in the sandbox if two options are close.

How resists and shred stack

Resists never add up. They stack multiplicatively:

Total resist = 1 − (1 − r₁)(1 − r₂)…

Two 20% sources give 36%, not 40%. Resist reduction ("shred") from several sources stacks the same way, and the result is then subtracted from the target's total. That makes shred worth more against heavily resisted targets. If shred is bigger than the target's resist, the target takes bonus damage.

Bullet and spirit resist are tracked separately. The calculator lets you list each source so you don't have to do the stacking by hand.

A worked example

A hero with a 40 base bullet, +30% weapon damage, no flat bonus, shooting a target with two 20% bullet resists at point blank:

40 × 1.30 = 52
Resist: 1 − 0.8 × 0.8 = 36%, so 52 × 0.64 = 33.3 per body shot
Headshot at 1.65×: 54.9

Add 10% shred and the effective resist drops from 36% to 26%, so the body shot becomes 52 × 0.74 = 38.5. The calculator shows these steps one by one and tells you how many hits it takes to drop a target.

What the tool still doesn't do

Damage over time and ability exceptions. Some abilities have special rules. Use their tooltip numbers per tick.
Barriers, healing and lifesteal. Kill checks use raw health.
Conditional item effects. Stack and proc-based items need you to enter the current value yourself.
Hero-specific falloff ranges. The slider is a percentage of your hero's range.
Patch changes. Re-check your inputs after each update. The formulas were last verified in October 2026.

Takeaway

Know which side of your build you're investing in (weapon for bullets, Spirit Power for abilities), keep track of falloff and headshots, and remember that resist stacks multiplicatively while shred is subtracted. The Deadlock Damage Calculator handles the arithmetic so you can focus on the decision.

See also: Three Deadlock calculators that work together for how the damage, stat scaling and burst tools fit one workflow.