I don't really understand this. Isn't that a bad thing? Or maybe does it mean technologies cost 10% less points? It's certainly not clear.

I really wish everything that was a bonus was a certain color (white since everything is) and if it was a penalty it would be red or something then even if the -/+ wasn't clear you could just tell by the color.

The wonder has a local system bonus to  but a global empire penalty to . 

The way it works is:

• The system you build ITER in gets a 10% per system level bonus to
• You get an empire-wide 10% penalty to

The idea is that the planet you build it on produces enough  for the 10/20/30/40% bonus to make up for the empire-wide penalty.

I don't know in which order these modifiers are applied in ES2 but working out the profitability thresholds is fairly simple maths.

Warning: assumptions about game mechanics begin here.

I will assume here that bonus applies at system level and the penalty applies to the sum-total of all  output. So:

[ (ITER system  + bonus%) + all other system  ] - 10%

Here's a table that shows approximately how much  a system has to output (as a % of your total ) so you get an overall benefit from ITER, per system level:

ITER System level	1	2	3	4
Min.  output from ITER system as % of total		56%	37%	27%

Under this assumption building ITER on a level 1 system will always result in a net loss of . 

A level 2 system has to account for at least 55% of your total  to result in a net increase, etc.

For example, you have 2 systems:

• System A is level 2 and produces 6
• System B is produces 4  (system level irrelevant)

Your total  output is:

6+4 = 10 

If you build ITER on System A the new total will be:

[ (6 * 1.2) + 4 ] * 0.9 = 10.08

Instead, if System A produces 5.5  and System B 4.5  the overall total is still 10, but ITER is a waste of resources:

[ ( 5.5 * 1.2 ) + 4.5 ] * 0.9 = 9.99

Hope this makes sense.

If anyone knows exactly how production these bonuses are applied I'd be keen to know.

Uhm... I think you got it all wrong. The tooltip is confusing.

That empire-wide effect is positive, as it cuts the empire cost of the technologies. Affects all future technologies researched as a passive bonus.

NInakoru is right. Its +10% sience for the system and -10% on the siencepoints needed for research. 

BTW: this kind of reduction of prices is not just summing up the percentages but multipling them. 

EG: omnisience max bonus is a reduction by 50% and when you finish the sophons questline you get another reduction of 50% for one wing of the researchtree. But theese techs aren't for free now ;)

Its 0.5*0.5=0.25 as the remaining price of techs. So it is a reduction of 75%.

I guess buyout- and industrial pricereduction for ships are working the same way.