Crate doesn’t care what you do (largely) with anything Grim Dawn related as long as you aren’t trying to profit off of it. There is a quote somewhere out there where Zantai says this, more or less. Trying to find the one I’m thinking of.
Here it is:
I’ll assume that applies to fiction as well.
Also “fan-made”, which ended up coming about partially because of the above board-game thread…