District Costs

[Leyrann]

You lost me on that one, can you clarify?
There certainly is indications here that you should avoid discovering holy sites, harbour's and/or theatres if you do not want to use them and you will get cheaper districts because if it.

I had reduced the 25 to 20 in my game files because I thought they indicated the speed of the district scaling.

 

[c4c6]

Yeah! The number of available district types is significant.
Also: "Discounts are turned ON based on completed districts and triggered by the completion of techs / civics or finishing districts."

In #117 turn 44 you have 5 completed districts and 4 available types, "avg" is 1.25
In turn 45 5 completed districts and 5 available types give "avg" = 1.0
So I'd say the civic / additional available district type triggered that & discount is given for Theater & Holy Site, but also for Campus, because <= "avg".
No discount for Commercial Hub, because > "avg" already underway.

Why no discount for Holy Site in turn 44? Possible _minimum_ constant numbers seem to be smaller: in #80 3 Encampments allowed discount for Campus & Holy Site ...

Until turn 43 were more districts underway than completed. Maybe this inhibits the discount ... (1 turn delay because the sequence of calculations)

 

[Victoria]

So using just average it does not quite work, it seems to flicker in and out... but then the formula does not work every turn 100% either!.... it's like it jumps half the cost to the new price for a turn which is very weird... so will go from 94 which it has been for a while to 102 prod for 1 turn before settling on 108...This may be some of the reason things do not work 100% all the time, probably a sequencing issue. I have noticed that if I restore a save it is correct. But save restore every turn is a pain.
I'm not next to the comp but I'll show you what looks odd visually when I get a chance. I think the formula you propose is either correct or close but ruined by sequencing.
I think the techs bit just makes sure you do not get too much discounting early.

 

[c4c6]

I'm not next to the comp but I'll show you what looks odd visually when I get a chance.

Nice cliffhanger btw.

In the meanwhile I sum up:
Preliminary draft
The effective cost is calculated & LOCKED IN upon placing down a district, even if the production is changed immediately and many other things are actually built before the district on purpose.
(67 Techs & 51 Civics in game, rounding down)
District cost = 60* (1 + 9*[ 100*Larger of{ Number of Techs/67 OR Number of Civics/51 } ]/100)
- Aqueduct 50, max 500
- normal districts max 600
- district types rarely used max 450 (@25% discount)
Aqueduct, Neighborhood and Spaceport don't receive discounts ("diversity of your districts" not applicable, because victory type respectively map specific or just style of play). So Aerodrome, Campus, Commercial Hub, Encampment, Entertainment Complex, Harbor, Holy Site, Industrial Zone & Theater Square can receive the 25% discount.
TBD "less than average" is calculated by adding all completed and/or uncompleted districts of this types _you_ have and then dividing by the number of districts types _you_ have currently available (depending on techs & civics).

To avoid, that if you have just one completed district all other district types would be at reduced price, at least 3 completed districts (different or same) are needed to get discounts. Also having more districts underway than completed inhibits the discount.
Discounts are turned ON based on completed districts and triggered by the completion of techs / civics or finishing districts.
Discounts are turned OFF based on completed+uncompleted districts and triggered by the completion of techs / civics or placing districts.

 

[Victoria]

A slight change of subject but still bang on the thread title (sorry, my mind wanders)... this is a bit geeky but interesting to perfectionists I guess. The prod cost is the production cost of creating a district if that tree was chosen for being cheaper.

While there is a tendency to not complete techs we to tend to have to complete techs to get a good government and Feudalism/Civil Service so I thought I would just analyze the costs to make it clear. We tend to want to finish our early civics

1. You can complete 8 techs without risking getting more expensive than civics at the level of Political Philosophy
2. You can complete 12 techs without risking getting more expensive than civics at the level of Feudalism or Civil Service.

Naturally these do not include Mysticism or Military Tradition
If you are racing down one tree you do not really need to half complete the other tree unless becoming excessive.
Its weird how odd numbers techs add more production than even numbered techs

 

[c4c6]

Its weird how odd numbers techs add more production than even numbered techs

I'd say it's full purpose, with the chosen numbers ...

100/67 is a tiny bit smaller than 1.5 (3/2), so modulo 1.492537 rounded down alternates rounding errors of nearly 0.5 and nearly 1.0

(100/51 is a tiny bit smaller than 2.0 (4/2), so modulo 1.960784 rounded down always gives rounding errors of nearly 1.0)

But what does this mean for the expansions? ... eg. the tech Railroad should be added ...
the next 'magic' number would be (4/3) ... indicating after the expansion there will be 100/76 techs?!!

 

[Lily_Lancer]

The final result turns out that the mechanism only works when Avg>=1. I finally made the last step recently. Thanks to everyone here. Congratulations.

I posted this on
https://forums.civfanatics.com/threads/district-discount-mechanism.625743

 

[c4c6]

Thank You, Lily_Lancer, for working out the last missing details ('Built' are all completed and/or uncompleted districts of this types _you_ have // Discount requires 'Built' >= 'Available' // 'Available' and 'Built' are refreshed only if a tech or civic is finished).

Great job! Again: Thank You!!!