Research Assist Math is wonky

[Taishan]

Research assist is supposed to help with research from jobs by increasing it by 10%. The research from jobs (not just researchers) are 11.85 physics, 17.77 (11.85+5.92) social, and 16.74 (11.85 + 4.89) engineering. When I research assist, this goes up to 12.65 physics, 18.97 social (12.65 + 6.32), and 17.87 engineering (12.65 +5.22). This is not a 10% increase. Am I missing something or is this a bug?

 

[Ryika]

Almost all modifiers are additive in Stellaris, not multiplicative. You already have other modifiers on your researchers, so the actual increase will be less than 10%.

A researcher produces +4 of each science types, you have 11.85 physics from, presumably, 2 researchers, so that's 11.85 / 8 = 1.48125 ...48.125% bonus before Assist Research.
Assist Research adds 10%, so 58.125. We multiply it withbase value: 8 * 1.58125 = 12.65, which is the amount you're actually producing.

 

[fusei]

Research modifiers are additive, not multiplicative, meaning the increase will always relate to the base value, not an already modified value. You likely already have +40% modifiers from tech and some minor modifiers from stability and the governor.

 

[Taishan]

I see, thank you both for explaining!

 

[MathyM]

Research modifiers are additive, not multiplicative, meaning the increase will always relate to the base value, not an already modified value. You likely already have +40% modifiers from tech and some minor modifiers from stability and the governor.

I think Research modifiers are separate from Researcher Output bonus, since the former acts on how much research points you need to unlock the tech, and the latter acts on how much research points you produce per month from jobs.

So the research speed bonus from e.g. Materialist does not stack additively with Researcher Job modifier, making it quite more powerful.

That's all AFAIK, though, would be nice if someone could confirm that.

 

[blahmaster6k]

I think Research modifiers are separate from Researcher Output bonus, since the former acts on how much research points you need to unlock the tech, and the latter acts on how much research points you produce per month from jobs.

So the research speed bonus from e.g. Materialist does not stack additively with Researcher Job modifier, making it quite more powerful.

That's all AFAIK, though, would be nice if someone could confirm that.

Research output boosts are additive with each other, research speed modifiers are additive with each other, and the first sum is multiplied by the second sum to determine your final research speed.