It runs the function twice - that's how it works. So rather than halving the value for the next plot (which would be weird to temporarily halve), it simply doubles the rate.
Thanks for that confirmation. By the way, please let me know if I am cluttering up this thread with this topic and I'll go start a new thread on it.
Actually on 50 Monument makes it 35.
I just tested the stacking effects of GoE, monument and Ger. I am assuming the code for Angkor is identical to these other 3.
I can now confirm that the rounding is always to the nearest 5 (or 2) and can be up or down.
The result is entirely not what I expected.
There are NO diminishing returns on stacking these 3 "SET PlotCultureCostModifier=25" bonuses.
Up to the 7th tile, the base tile costs are 20-50-100-160-220-290-365-440-520 as you had presented a few posts ago.
With all 3 in force (70% reduction), the results are always consistently accurate. 6-15-30-50-70-85-110
The 6 was surprising because it is the only non 5 figure even though the calculation result is actually 5!
The first tile went from 20 to 15 (GoE) to 10 (Monument) to 6 (Ger). I think this is the reason:
if(iCultureThreshold > iDivisor * 2)
when the result is below the base of 15, the rounding is to nearest 2.
The reason why I'm surprised that the effects stacked without diminishing returns is because I had always thought that it should not be possible to stack the bonus to the point of 100% in order to not have FREE growth every turn.
Here's what else I had learn from this discussion:
1. GoE was wrongly coded/described. With it only providing 20% instead of 25% as previously thought, the current max bonus is 95% reduction (GoE, Mon, Ger, Angkor). This point is kinda moot though, because it will be fixed and because 2.
2. This line in the function Gazebo posted caught my eye
iModifier = max(iModifier, /*-85*/ GC.getCULTURE_PLOT_COST_MOD_MINIMUM()); // value cannot reduced by more than 85%
Meaning that even with GoE (20 or 25%), Mon, Ger and Angkor, the max is 85%. This makes Angkor Wat works at only 15% (or 10% once GoE is fixed)
This is only possible for the Mongol with Ger. With Ethiopia, the max is 83% (GoE, Stele, Angkor). All other Civ can only manage 75% max.
The costs of tiles would be:
2-8-15-25-35-45-55-65-80 at 85% and
6-15-30-40-55-70-90-110-130 at 75%.
3. Tradition policy Sovereignty does not truly provide 25% deduction and interacts entirely differently with the formula. Based on the cost you shared, the cost of tiles with only bonus from Tradition policy is:
15-30-45-60-70-85-100-110-125
Based on this, I can see that Sovereignty alone would catch up to a maxed civ's 75% bonus by the 8th tile and overtake it from the 9th onward. I can imagine that it'll continue to snowball beyond that, with the % reduction creeping up past the otherwise hard capped 85% eventually.
Stacking other bonuses on it:
2-4-6-8-10-12-15-15-20 when coupled with max 85% reduction bonus. A
96% reduction on the 9th tile, with the 85% bonus accounting for only 105 points or 20%.
4-8-12-15-20-20-25-30-30 at 75% for other Civs. A
94% reduction on the 9th tile, with the 75% bonus accounting for only 95 points or 18%.
In summary,
- GoE does not work like Divine Right and does not increase rate of culture accumulation.
- Sovereignty is the most important border growth bonus if going for the border blob strategy or if one simply wishes to spread fast.
It is still worth stacking other bonuses on it, but it is not going to be as good a return on investment and will only really help early city tile growth.
Angkor Wat is really quite a poor wonder to rush if one already has GoE, since it's other properties are just +1 to GE gen, culture and faith. For the Mongols, this is an even worse deal as they have the Ger.
This is going to entirely change my game!