.....which of the games?

It's a year later, but I'll follow up on the question if OP won't. I'm specifically curious about Saints Row 4.

Most mods I've found are set up for the Steam version, and in their instructions reference files and folders that don't seem to exist in the GOG version (things like ".xtbl" files and a "Files" folder, for example).

I know there's a "mods" folder in the GOG version, but I'm wondering what to do when a mod author specifies for you to replace a specific file with one of their own.

Anyone in the know who feels like shedding light on how to apply a Steam mod to the GOG version (or confirm that it isn't possible, if that's the case) would be much appreciated!

In case anyone had the same question and is wondering, a simple experiment yielded success.

Placing modded files into the "mods" folder (whoda thunk?) within GOG's Saints Row 4 folder -- and nothing more -- seemed to apply them exactly as needed.

Specifically, both a texture mod as well as an early-unlock mod worked as intended and seemingly without issue (was able to play, save, load, and keep playing without any obvious problems).

I wouldn't go as far as to say it'll definitely work for all mods across the board, especially as these are very simple mods, but it's a good sign.

Hopefully this helps anyone who had the same question!