I just figured I'd ask, knowing what the answer likely is...
Is anyone aware of a software library (i.e. in the C++, C#, Java... sense) that contains the Pathfinder 2E ruleset, for 'easy' integration with 3rd party game engines?
I assume the OwlCat folks rolled their own "Pathfinder Adjacent" rules engine for their games.
The closest thing I can come up with is the Pathfinder 2e system for Foundry, perhaps that could be adapted?
Anyway, just looking for thoughts from other folks out there who may find such a product of interest.
Note: I'm not looking to get it for free, but like anyone, if it's free as in beer I'll take it too :)
p.s. I also know all the caveat such as 'this isn't well defined and is usually determined by GM ruling' where the developer using the library will have to make those determinations in their code.
All I can do is agree with and corroborate your presentation of the problems you have already listed.
TTRPG rules are not algorithmic natively. A finite and pre-adjudicated subset of them could be created as a library. I am not aware of any that are open source.
Yes there's no public library with the full PF2e rules but foundry PF2 modules have many PF2e rules written in JS but this rules aren't agnostic, they are written focusing into foundry interfaces. So probably you can use the as reference but it will pretty hard to use them as code reuse.
Maybe ask the creator of Dawnsbury Days?