Thanks, that is helpful. I guess the analogy breaks down, though, when I hear that different countries can own different parts of a 'state': that certainly isn't the case with US states! But I get the basic idea of a geographical area that already has a name at the start of the game, like 'North Westphalia', and different countries can own different provinces within that territory. For convenience those are termed 'states' when they are cored and become an integral part of the owning country. Have I got that more or less right?
So, your reply is mostly right, but I've added an emphasis to a part I want to address: Coring a province is not the same as making it a state. There are two "types" of cores, and, 'helpfully', one of them is just called a "Core". The other is a
Territorial core. From here, I'll go into detail on the differences between the two below, but first, I want to comment on
areas.
In terms of geography, provinces are grouped into "
Areas". North Westphalia is an
area, which contains the provinces Osnabrück, Dortmund, Münster, and Meppen. The
area of North Westphalia can be a
state or
terrirtory for nations that own one of the four menioned provinces. Every area will be a territory when you acquire provinces in it for the first time. That's technically a half-truth, which I'll elaborate on later. For now, let's go through an example, step-by-step:
Suppose I'm playing as Portugal, and I currently own none of the provinces in North Westphalia. That area is neither a state, nor a territory for me. Then, I conquer Meppen. North Wespthalia becomes a territory for me, and Meppen is an uncored province, which causes overexentsion. Which is a bad thing. I can now spend admin points to core Meppen. This is not instant; By default it'll take a few years, but that length of time can be reduced, although I won't go on a tangent about that. However long it takes, when the process finishes, I now have a
territorial core on Meppen, and it no longer produces overextension. The minimum local autonomy (MLA) in Meppen is 90%, because North Westphalia is a territory.
Now that Meppen is cored, I can make North Westphalia a
State. This lowers the MLA in Meppen to 50%, inceases the governing capacity cost of the province, and permits me to upgrade the territorial core in Meppen to what the game refers to as a "Core", at the cost of additonal admin points (Upgrading a territorial core is instant, though). The playerbase usually refers to this type of core as a "full core", or (less frequently) a "state core". To emphasise:
Coring a province in a new area does not make that area is a state, but it permits you to make that area a state, and making the area a state permits you to make the provinces in that area (full) cores. Any further land I take in North Westphalia will be part of a state, and coring it will create a full core. (This doesn't affect the amount of in-game time it takes.)
Everything below is less relevant to what you said, so you can skip right to the summary at the end if you want, but if you'd like a more complete overview of cores, states, and territories, read on.
Using strictly in-game terminology, "territorial cores" and "cores" are different things, but playerbase generally refers to them both as a "type" of core. An important thing to remember is that even if a territorial core is not the same as a (full) core, a province with a territorial core is never "uncored". The most important reason to "core" a province is avoiding overextension, and from that perspective, the specific outcome of coring aprovince is irrelevant provided it removes the overextension. Indeed, since not all uncored provinces causes overexstension (specifically, provinces that were uncolonised at the beginning of the game never cause overextension), you'll often see players leave those provinces completely uncored, to save their admin points for other things.
Now I want to talk about the other important difference between territorial cores and "full" cores: Permeance. If you lose land, your full cores will remain (Unless you sold the land), giving you a time-window where you'll have the "Reconquest" casus belli on whoever owns that land, which lets you take back the land while incurring less agressive expansion than normal, as well as no separatism in the province, and no need to go through the coring process again. In contrast, territorial cores are lost immediately along with the land.
Note that the above paragraph strictly refers to the
cores in the
provinces. It is not related the the state/territory status of the
area. If Portugal makes North Westphalia a state, but doesn't upgrade the territorial cores in the provinces it owns there, those territoral cores will still be lost if those provinces are lost, even though the provinces being lost are part of a state. Likewise, if you have full-cores on provinces in a territory, the full-cores will remain if the land is lost.
If you're still reading, you might be wondering "But how could I have full-cores in a territory, when making an area a state is what permits me to make full-cores in the first place?" Certain minds might even say "Aha! Can I make an area a sate, create full-cores, then turn it back into a territory, in order to keep the full-cores for reconquest if needed, without having to pay the extra governing-capacity cost?" to which my answer is: Sorry, no. Making a state into a territory downgrades any full cores into territorial cores. with no admin point refund. But to elaborate on how you
can have full cores in a territory, I get to elaborate on that half-truth I mentioned in the end of the second paragraph.
What I said was, "Every area will be a territory when you acquire provinces in it for the first time." This isn't wrong, but it would be more precise to say "Every newly-acquired province will be part of a territory, unless, at the point in time when you acquired that province, you already held land in the same area, and that area is currently a state" You can probably see why I stuck with the half-truth earlier. To put it another way: State-status is not preserved when all land in an area is lost. But full cores
are. To illustate:
Let's say Portugal owns the entirety of North Westphalia, stated, ("Stated" as in "the area North Westphalia is a state". Not simply that the statement has been made that Portugal owns the entirety of North Westphalia. Though now in our example, the area, and that statement, have both been "stated".). Then, the Ottomans conquer all four provinces in the area. Portugal's full-cores remain on the provinces. If Portugal reacquires any or all of those provinces, they will still have the cores, but because Portugal is acquiring land in an area that it did not already own land in, North Westphalia is a territory.
Alternatively, if Portugal is vassalised and integrated by... Let's say, Mexico, Mexico recieives full cores in any provinces that Portugal had full cores on. But any of those provinces in areas that were not already Mexican states upon intergration will be territories, regardless of the cores on the provinces themselves.
To summarise: The creation, presence and type of
core in a
province is not the same as the territory/state status of the
area in which the province is contained. Coring a province does not create a state, and making a state does not create a core, but a territory containing uncored provinces cannot be made into states, nor can full-cores be created in territories (though pre-existing full-cores can be reacquired.)
Any questions?