# Only five (really six) things are true damage multipliers - everything else is additive noise inside them

Weapon Damage, Skill%, Main Stat, the Additive bucket, each independent Global [x]% source, and Enemy Damage Reduction are the only genuinely separate multiplicative stages. Every '[+]%' tooltip stat you own, no matter how different it looks, is just one more addend inside the single Additive stage.

Diablo IV patch 3.2.1. Category: multiplier stacking. Evidence: Confirmed.

## Detail
Diablo 4's hit damage is a chain of stages multiplied together in sequence. Two stats are only additive with each other if they share a stage; anything in a different stage is multiplicative. Players intuitively treat every distinct-sounding stat (Close Damage, Crit Damage, Vulnerable Damage, Core Skill Damage, Overpower Damage) as its own lever, but almost all plain '[+]%' wording folds into one shared Additive Damage Multiplier bucket. Only stats phrased as 'x[N]%' (uniques, Aspects, Paragon Glyphs, and the innate Crit/Vulnerable baselines) are separate multiplicative buckets that truly stack independently.

## Why it works
The engine literally computes Base * WeaponDamage * Skill% * MainStatMult * (1+SumOfAdditives) * (1+x1)*(1+x2)*...*(1+xn) * EnemyDR. Anything summed inside the single (1+SumOfAdditives) term shares diminishing returns with everything else in that term; anything in its own (1+x) term does not.

## Numbers
Beginner worked example from one guide: 100 base * (1 + 100% Physical + 40% Core Skill + 150% Close Damage) [[Additive bucket, summed to 290%]] * (1 + 135% Unbridled Rage [[a separate x% Global Multiplier]]) = 100 * 3.9 * 2.35 = 916.5 average hit.

## How to use it
Before buying a new '+%' affix, ask which stage it lives in. If your Additive bucket is already large, a new '[+]%' roll is worth much less than an 'x[N]%' unique/Aspect/Glyph of similar face value.