I still don't understand peace deals...

[Howl]

Thank you everyone for the valuable replies.
I will attach a savegame later, however it has of course progressed beyond this point. For example all provinces have been converted (from being Sunni I think).

(ii) AE for giving provinces/returning cores to subjects does not factor in religion, culture, etc..

Is this generally true? Or only if your subject already has cores on the province?
If it were generally true you could conquer wrong religion HRE lands for no increased AE if you gave your land to subjects?

 

[grotaclas]

(ii) AE for giving provinces/returning cores to subjects does not factor in religion, culture, etc..

Does this only apply for cores of the subject? Or only to the reconquest CB?
I tried this with the conquest CB by starting a new game as France, giving Carcassone to Foix(so that they have a border with Aragon), used add_claim 2990 to get a claim on the Aragonese province Teruel and declared a conquest war for that province. Then I used control 1978 to occupy the border province Roussillon. In the peace deal screen taking Roussillon as France gives 10 AE. And transferring the occupation to Foix also shows to give 10 AE in the peace deal screen. 10 AE would be consistent with an 1.75 multiplier from same religion and same culture group for Aragon, because the province has 8 dev(8*0.75*1.75=10.5).

I did a further test and gave Foix a core on the province and the AE decreased to 6. But that also applied when France took the province for themselves. This is weird.

Edit: fix broken code tags

 

[Tempscire]

Is this generally true? Or only if your subject already has cores on the province?
If it were generally true you could conquer wrong religion HRE lands for no increased AE if you gave your land to subjects?

Does this only apply for cores of the subject? Or only to the reconquest CB?

As far as I tested this, it is only related to retaking cores of subjects in reconquest wars.

I did a further test and gave Foix a core on the province and the AE decreased to 6. But that also applied when France took the province for themselves. This is weird.

I just tested this and I am pretty sure that this is the result of 8*0.75*2/3*1.75=7 times something slightly smaller than 1 as France starts with positive prestige. Try playing around with the prestige if you want to verify this.
I did some further testing and the following seems to be the case:
(a) If you take a province with the reconquest CB that a subject has a core on then AE is dev*0.75*0.25*AEmod. [AEimpact does not apply. I tested this with 1.5,1.75 and 2.0 provinces]
(b) If you take a province with another CB (I only tested conquest and reconquest that does not apply, when taking non-core provinces) that is a core of your subject then AE is dev*0.75*2/3*AEimpact*AEmod. [For some reason there is a factor of 2/3. This might be related to the difference between return core and cede province].
This seems to be independent of the country actually taking it (you or your vassal). As long as you use the same cb and it is valid then the AE is the same.

Edit: (b) also seems to apply with the imperialism cb.

 

[Howl]

For what it is worth here is the save game.
All DLCs except for Emperor and Leviathan.

Behold the glory that is Spain. They did have Naples in PU as well at some point, but lost a restoration of union war.

 

[grandadmiralbob]

When you hit the option to "return cores" the losing nations actually loses their cores on that province. The only time this isn't true is if it is their primary culture.

 

[grotaclas]

I just tested this and I am pretty sure that this is the result of 8*0.75*2/3*1.75=7 times something slightly smaller than 1 as France starts with positive prestige. Try playing around with the prestige if you want to verify this.

You are right, the AE is 7. I got 6 AE in my test because of the prestige and the rounding.
I think it is not 0.75*2/3, but the 0.75 for ceding a province is replaced by the 0.5 for returning a core to a vassal. The 0.5 is defined in defines.lua:

PO_RETURN_CORES_AE = 0.5,                  -- (Per core, only applied if returning cores to vassals of winner)

I tried changing this value to 0.1 and the AE changed accordingly
But I don't know why this is applied when not actually giving the province to the subject with the core

(a) If you take a province with the reconquest CB that a subject has a core on then AE is dev*0.75*0.25*AEmod. [AEimpact does not apply. I tested this with 1.5,1.75 and 2.0 provinces]

Are you saying that this applies when I take a province for myself on which only the subject has a core? Then I can't reproduce it at all for the reconquest CB as I seem to get the normal AE for taking a province(dev*0.75*AEmod*AEimpact). Was the province maybe unoccupied in your test and went to your subject per default?

Cede province: 63 (dev) * 0.25 (CB) * 0.75 (Cede Province) * 0.9 (AE modifier)~10.63 [recall that your AE modifier is applied]

I think this is actually 63 (dev) * 0.25 (CB) * 0.5 (returning a core to a vassal even though we are using the cede province tab in the peace deal) * 1.5 (AEimpact from same religion, but different culture group) * 0.9 (AE modifier)~10.63. To confirm that I did the following test:

1. start as Castile in 1444
2. vassalize nav
3. add_core [prov_id] NAV to give Navarra cores on three provinces of Aragonese culture
4. set_base_tax [prov_id] [tax] to change the dev of the three provinces so that the sum is 63
5. prestige -8 to set the prestige to 0 so that there is no AEmod (not sure if it was exactly -8)
6. declare a reconquest war against Aragon for one of these cores
7. check the peace deal for ceding the provinces to Navarra. The AE is 15 which matches 63*0.25*0.5*2=15.75
8. tag mor to switch to Morocco and culture [prov_id] to change the culture of the provinces to Moroccan
9. tag cas to switch back
10. check the peace deal for ceding the provinces to Navarra. The AE is now 11 which matches 63*0.25*0.5*1.5=11.8125

Return cores: 63 (dev) * 0.25 (CB) * 0.9 (AE modifier)= 14.175

I can't reproduce that AE in my above test game. With a -10% AE modifier, I get 12 AE for 63 dev and without the modifier it is 13 AE. This is independent of the culture of the provinces. I also tested a bunch of 30 dev provinces (which is AFAIK the cap for AE) and I get 6 AE for one province, 13 for 2, 19 for 3 and 26 for 4(all with 0 AE modifier), so I think the AE for one 30 dev province is around 6.5. But with your formula the AE should be 30*0.25=7.5. But I have no idea how the actual formula could look like.

I did all my tests with the version 1.31.4

 

[Big Bad France]

The cost is extremely small if you let them siege your vassal in northern Scandinavia...
I have played this game from the beginning and I miss the AI fighting like a suicidal maniac. Sure when you are big the outcome is the same, but at least it drains some resources.
In this case they would have had a reasonable fighting chance. I am much larger landwise, but we have about the same amount of troops. They could have used defensive terrain, hid behind their fortresses, whatever. Pre 1.12 I would never have declared this war, much too costly. Now? Place all troops next to Muscovy, declare, move in and to the adjacent provinces. After the siege is finished their armies are probably sufficiently far away, that you can spread out and siege them at leisure.

If the AI were playing the war right, they would park their armies safely behind their forts and feign attacks often enough to ensure that you had to keep full stacks on the forts. Then they would actually engage you when the percentage flipped positive, effectively draining your manpower through attrition. Of course, that would require programming the AI to behave differently where attrition is high than they do where it is low.

 

[Tempscire]

You are right, the AE is 7. I got 6 AE in my test because of the prestige and the rounding.
I think it is not 0.75*2/3, but the 0.75 for ceding a province is replaced by the 0.5 for returning a core to a vassal. The 0.5 is defined in defines.lua:

Yes this seems to be correct. I just did a short test and did not change defines.

Are you saying that this applies when I take a province for myself on which only the subject has a core? Then I can't reproduce it at all for the reconquest CB as I seem to get the normal AE for taking a province(dev*0.75*AEmod*AEimpact). Was the province maybe unoccupied in your test and went to your subject per default?

Sorry I formulated this somewhat imprecisely. I meant that you take a province for yourself or your vassal, for which the reconquest casus belli actually applies. I.e. if you take it you need to have a core on it.

I think this is actually 63 (dev) * 0.25 (CB) * 0.5 (returning a core to a vassal even though we are using the cede province tab in the peace deal) * 1.5 (AEimpact from same religion, but different culture group) * 0.9 (AE modifier)~10.63. To confirm that I did the following test:

1. start as Castile in 1444
2. vassalize nav
3. add_core [prov_id] NAV to give Navarra cores on three provinces of Aragonese culture
4. set_base_tax [prov_id] [tax] to change the dev of the three provinces so that the sum is 63
5. prestige -8 to set the prestige to 0 so that there is no AEmod (not sure if it was exactly -8)
6. declare a reconquest war against Aragon for one of these cores
7. check the peace deal for ceding the provinces to Navarra. The AE is 15 which matches 63*0.25*0.5*2=15.75
8. tag mor to switch to Morocco and culture [prov_id] to change the culture of the provinces to Moroccan
9. tag cas to switch back
10. check the peace deal for ceding the provinces to Navarra. The AE is now 11 which matches 63*0.25*0.5*1.5=11.8125

I just tested this and it seems to be correct, the problem with my test was that I did it with France as a country and Labourd as a Province. But France and Armagnac both have a core on Labourd and this seems to change things.

If I remove the core from Labourd then the AE for taking it is:
10*0.25(CB)*0.5(PO)*2(AEimpact from Navarra)=2.5
with the core it is:
1.875=10*0.25(CB)*0.5(PO)*1.5(AEimpact?).

There seems to be some impact of cores on AEimpact as also if one gets rid of the core of Armagnac but keeps the French core the AE is
2.8125=10*0.25(CB)*0.75(PO)*1.5(AEimpact?).

The precise numbers are from adjusting prestige and checking when the calculation rounds.

Note that this also might have some other prerequisites as I could not replicate this effect of cores when attacking Aragon as Castile in the example you proposed.

In the Livonian Order/Kazan/Muscovy peace deal the calculation 63 (dev) * 0.25 (CB) * 0.5 (returning a core to a vassal even though we are using the cede province tab in the peace deal) * 1.5 (AEimpact from same religion, but different culture group) * 0.9 (AE modifier)~10.63 should probably be correct as there seem to be no Livonian cores involved.

I can't reproduce that AE in my above test game. With a -10% AE modifier, I get 12 AE for 63 dev and without the modifier it is 13 AE. This is independent of the culture of the provinces. I also tested a bunch of 30 dev provinces (which is AFAIK the cap for AE) and I get 6 AE for one province, 13 for 2, 19 for 3 and 26 for 4(all with 0 AE modifier), so I think the AE for one 30 dev province is around 6.5. But with your formula the AE should be 30*0.25=7.5. But I have no idea how the actual formula could look like.

I tested this and I am certain that in you peace deal you get:
BaseAE=30 (dev) * 0.25 (CB) * 0.5 (PO) * 1.75 (AEimpact from Cores) = 6.5625

and in the other peace deal it should be
AE = 63 (dev) * 0.25 (CB) * 0.5 (PO) * 2.00 (AEimpact from Cores) * 0.9 (AEmod) = 14.175.

Therefore the AEimpact does get applied but it gets applied in a wrong way. (I am not sure if this is just an UI bug or the actual AE is affected by this as I only tested the UI). Which AEimpact modifier gets applied when seems quite obscure, but it seems to be related in some way to the primary culture of the nations getting the most AE/ participating in the peace deal. My current findings are the following:
As Castille returning a core form Aragon:

Aragons Primary Culture	Province Culture	AEimpact
Aragonese	Aragonese	1.75
Aragonese	Catalan	1.75
Catalan	Aragonese	2.0
Catalan	Catalan	2.0
Greek	Aragonese	1.5
Greek	Greek	1.5

Therefore the province culture does not seem to matter, but the primary culture does.

Returning Labourd from England also has an AEimpact of 2.0.

So the problems actually seem to be the following:
(i)The AE modifier for returning cores is wrongly applied if you take a province which only your vassal has a core on directly for yourself,
(ii)Having a core on a province seems to sometimes have an impact on the AEimpact modifier at least when using the reconquest cb. The exact conditions are unknown,
(iii)When using the return core peace option the AEimpact seems to be calculated differently. There seems to be a relation to a nations primary culture but not to the provinces culture. How this works exactly is unknown.

If you find out something about these unknown circumstances I would be very interested.

 

[Howl]

If you find out something about these unknown circumstances I would be very interested.

Impressive.
If it is any help my current save now offers ample opportunity for tests.
Commonwealth suddenly decided to be a bad neighbour while being on the losing end of the league war and I happened to hold a single Lithuanian core...
They are now willing to take a 100% peace deal. For easier viewing the occupation of every Lithuanian core has been transferred to Lithuania.

Game version is 1.31.3, no emperor, no leviathan.

 

[Howl]

This looks something like the peace deal I am going to take.
Ceding to Lithuania instead of returning as before has significantly reduced AE. However now it also has slightly lower warscore.
No one should have any administrative efficiency whatsoever. Lithuania has diplo ideas (0), I don't. I have 90 prestige, they -93. All combatants and provinces are catholic.
It is Polock, the war goal. It costs 7 war score to return and 4 to cede.