So there are a few options here. The first is just enabling the RNG cave system. It works, it just places the cave connections in weird spots and that will occasionally cause problems.

The map creation tools DO have an Underground Map option. That might work, but it does save it in a different file format. I should check how it interacts with the planes layers.

Another thing to check is if I can set Gates without a cave layer. If the random gen detects and uses them, that's great. But it could also break the map, crash, etc.

Having a .tga file for a caves is the easiest method, since it's basically just a process of making sure Layer 1 Gate and 2 Gate have matching keys, but drafting art and setting up the province borders does make it time consuming.

Definitely a weird process right now but that's mostly just system interactions being vague. That does give me options to test though. I should do a random gen map on the side just to see how the formatting needs change.

Yeah the style mismatch is what it is, but the idea would be to have a set of instructions that would allow anyone to generate a couple of playable caves on a given map and maybe spend like 5 minutes deleting weird connections if really necessary. This would allow all the converted maps to be "feature complete", as it were.

Yay Community Support!

Difficult, not necessarily, feasible, probably ?
My main understanding is that if you don't have a more curated underground layer for one of these and instead rely on the random map generation, it tends to have odd behavior and places almost all of its surface connections randomly, which could result in either some strange behavior or placements ? I'd have to double check, someone might be able to correct me.

Cave Starts do at least still operate the same way they did in Dominions 5 for maps that don't have a full Deep Cave layer, using preset Cave provinces, but this specific map was always pretty cave light in the first place. So at least one Cave-Start nation still has a spot to set in like the old days.

Anyways, I can give it a test and see how consistently it behaves, just bear in mind any deep-cave layer I enable (either the RNG ones or an attempted custom) would end up looking completely different to the original map style.

Thanks for all the work you've put into getting these maps up, it's not going unnoticed or unappreciated.

One thing on my mind is with the cave layer being introduced in dom6 a lot of nations would prefer or even depend on cave starts. How difficult/buggy would it be to get the game to generate a cave layer for these maps? Is it even feasible to do so?