ALL requirements for Lan

One round less would be already much better.

I didn't tested more rounds at this time, but I know today for sure, that every 10 rounds is a roundbreak, where you loose many years for Asia. So finish in R25 for Lan - or, in the Sakutako case, R35 not R36!

Specially for You pathdoc I evaluated the rounds and years (Europe, America) up to round 100+, but not for Asia I regret.

Note:
Roundbreaks for Europe are after R30, R40 ...

Keep your save, later you get more years that is sure, but if you can speedup just one round: try it! - the roundbreaks are really heavy, usually they cost more than 50 years.

𝘛𝘳𝘰𝘵𝘴𝘬𝘺, so I was just looking over the requirements for Lan, and I wondered, if I get a really good game, how many campaign stars is the minimum I need?

I have copied your basic numbers from the original post below for reference:
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Why is it so tricky to understand how and when to achieve an Asian princess?
Because you need a lot of rice 🌾 to rule Asia !
And you can't see directly how much rice you have.
Rice???
Yes rice 🌾!
How much rice ?
Sakurako 350 years 196 000🌾
Lan 550 years 308 000🌾
I will explain how it works

Rice 🌾 is the ressource of Asia. At the end of any conquest you can challenge asia and your rice🌾 will be evaluated. The resulting years, rounded down in intervals of 50, are displayed and you will obtain a princess if you have enough 🌾 / years.

The sources to collect rice are:
Conquest resources (max. 70 000🌾)
Conquest rounds (max 105 000🌾)
Campaign progress (max. 70 000🌾)
Generals in your Headquarter (max. 175 000🌾)

Campaign progress

For every single ⭐ you get in your campain you get 170🌾
So 170🌾 * ⭐ is the amount of rice you get here, with a maximum of 70 000🌾 (411⭐)

Conquest rounds

You get rice for the performance of your conquest: Faster conquests give more rice.

Rounds America Europa
up to 20 105 000 🌾 105 000 🌾
21 100 400 🌾 100 400 🌾
22 97 800 🌾 97 800 🌾
23 95 200 🌾 95 200 🌾
24 92 600 🌾 92 600 🌾
25 90 000 🌾 90 000 🌾
26 39 300 🌾 87 400 🌾
27 37 350 🌾 84 800 🌾
28 35 400 🌾 82 200 🌾
29 33 450 🌾 79 600 🌾
30 31 500 🌾 77 000 🌾
31 29 550 🌾 16 550 🌾
32 27 600 🌾 14 600 🌾
33 25 650 🌾 12 650 🌾


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Now if I've got this right:

So... 308,000 rice for Lan.
Subtract 175,000 rice for generals in the HQ, that leaves 133,000 rice.
Assuming a perfect conquest resources (which we can never get because food is always consumed AFTER it is generated; some gold and wrench trading has to occur, but let's keep it simple), that's another 70,000 off, which leaves just 63,000 left to earn.

That would mean that if we had perfect campaign progress, another 70,000, WE WOULD ALREADY HAVE ENOUGH FOR LAN and ANY length of battle would be enough to get her.
Or to put it another way, if somehow we could get the 25 round finish with perfect resources, we should be able to get Lan without ANY campaign progress at all.

The truth for most lies somewhere in between.

Or have I made a mistake somewhere?

I just want to say thank you!
The only worthy thread about getting Lan. Precise to the point.

Is there another for victoria?

What campaign are you on? To me 38 more campaign stars feels easier than 25 rounds lol

if you're on Austro-Turkish war, yeah that's not a fun one at all