How do you upgrade fortresses?

[CptBloodclot]

ah okay...that makes sense now...cheers

[Taqwus]

...if you capture a fortress that you don't like, you could destroy it and build one of your own. You'll pay full price and will be dealing with the lack of a fort for a while, so it's not really an 'upgrade'.

Might matter if, say, you're playing a resource-intensive nation and you capture a primitive type with no administrative value.

[Micah]

Still generally going to be better to build one a province over though, unless the captured fortress has very good siting combined with bad admin. LA ermor perhaps. Or any of the nations that can build a swamp city instead of a swamp fort.

Any fort counts as (essentially) admin 50 for the province it's built in, so you'll never get any additional resources out of the province it's on top of.

[Twan]

The fun thing with LA Ermor castles is their 0 supplies, always destroy ermorian castles and rebuilt if you are a living nation, or you'll have bad surprises the day there will be a siege.