Additive Damage worth the same as a given x% Global Multiplier = x% * (100% + your current total Additive Damage). Use this to stop guessing which upgrade is bigger.
Because the two buckets combine multiplicatively with each other but differently within themselves, you cannot compare a '+%' roll to an 'x%' roll at face value. The correct comparison scales the Additive roll by how big your existing Additive total already is.
A new x% Global Multiplier always gives exactly +x% more damage regardless of your other stats (it is independent). A new Additive roll of the same nominal size gives less the more Additive you already have, per mult_crowded_additive_diminishing_returns. Setting the two relative-gain expressions equal and solving gives the comparison formula.
Example: with +1000% existing Additive Damage, a new +10% Global Multiplier gives (1.10/1.00)-1 = +10% more damage, while a new +200% Additive Damage source gives (1200%/1000%)-1 = +20% more damage in that specific scenario - the Additive roll can still win, but only because it was unusually large relative to a small x% option.
Before an upgrade decision, note your current bottom-line Additive total, then plug both candidate stats into the relative-gain formula rather than comparing raw percentages.
multiplier stackingConfirmedAll
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