Both of the game's two most iconic damage stats follow the same wording-dependent split as mult_summed_multiplier_wording_trap: plain '[+]%' rolls are Additive-bucket, 'x% ... Multiplier' rolls are Summed-Multiplier-bucket, and the innate baseline (+50% Crit, +20% Vulnerable) is always its own fixed, unmodifiable Global Multiplier untouched by either.
This means a fully-optimized character can be running THREE separate Crit Damage sources at once - the fixed +50% baseline, a pile of plain '[+]Critical Strike Damage%' gear rolls in the Additive bucket, and one or more 'x% Critical Strike Damage Multiplier' uniques in their own Summed Multiplier bucket - and all three genuinely stack with each other multiplicatively as a group, even though two of the three internally add.
It follows directly from how the affix_buckets table assigns Critical Strike Damage and Vulnerable Damage: 'Plain wording -> Additive bucket; Multiplier wording -> Summed Multiplier; innate baseline -> fixed Global Multiplier', all three combining multiplicatively as separate stages.
When theorycrafting a Crit or Vulnerable-heavy build, tag every source you own by exact wording before assuming they all stack the same way; this changes which slot upgrade is actually worth more.
multiplier stackingConfirmedAll
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