With the introduction of the moon/mars wonders, I note that some of them provide bonuses in the form of -% infra cost and/or upkeep. Since the effectiveness of -% bonuses supposedly gets diminishing returns the more of them you have, I am curious about how bonuses are aggregated together for stacking purposes.

For reference, sample infra reduction -% values:

Resources - Construction set (Lumber, Marble, Iron, Aluminum): -29% total
Improvements - 5 Factories: 5x-8% = -40% total
Wonders - Interstate System: -8%
Government - Some government types: -5%

The total isnt simply adding all of these up; if it were, the bonus here would be on the order of
-29% - 40% - 8% - 5% = 82% total reduction = 1 - 0.82 = 0.18 base infra cost

If something like this is how bonuses are aggregated, then the full result would be something like:
1 * (resources) * (improvements) * (wonders) * (governments), or in this case 1 * (1 - .29) * (1 - .4) * (1 - .08) * (1 - 0.05) = 0.372 base infra cost

In short, the more 'groups' there are for lumping bonuses together, the less effective any single -% bonus is; i.e. from the above example the -5% from government isnt actually -5% from the base, but rather -5% * -29% * -40% * -8% = -1.95% from the base.

A worse scenario would be each individual wonder/bonus resource/etc being counted separately; i.e. 1 * (interstate) * (moon/mars base) * (resources) * (construction BR) * (steel BR) * (government) * (events) ... etc

So my question if anyone can tell me how much incremental -% boosts (such as those provided by the expensive moon/mars wonders and some of their bonus resources) are reduced in effectiveness due to how many divisions there are in stacking these bonuses together. I understand wonders are not meant to be a huge boost, but am interested to hear details.

Thoughts?

-Preston

Afaik, this is exactly how it works. If it wasn't done this way, it might be possible to go into negative amounts which wouldn't make any sense.



Sure, it's reduced a lot compared to if you simply added them all. But it doesn't matter. They are still worth it, and the game is balanced as is.

Construction -5%
Aluminum -7%
Iron -10%
Lumber -6%
Marble -10%
Construction gives you a price reduction of 1 - 0.95 * 0.93 * 0.9 * 0.94 * 0.9 ~ 32.7%

Yeah, relational bonuses multiply (the only exception to this are improvements of the same type which add).