At the time, there was no internet. At least, not that I had access to. The local library and book stores had limited selections of Lovecraft (Thanks, Del Rey for the affordable reprints) But finding stuff by other authors, that was really hard.
And if it wasn’t for the fact that most of the descriptions of the foul beasties that make up the wonderful world of the Call of Cthulhu included descriptions from the stories with citations, I wouldn’t have even known that there were stories out there for me to look for.
At the time, this was a revelation for me. I had no idea that there was this wealth of cosmic horror out there. Stuff I would have had no other way of finding out about if it wasn’t for the role playing game.
Boy, do we live in a different world now. And boy, is it fun to live in the future!
Mind you, it took me a long time to eventually find some of those works. I didn’t find and read Ramsey Cambell’s Lovecraftian stories until I was in my thirties. Which is a shame because they turned out to be really good. His Severn Valley stories create their own internal mythology of cosmic nastiness.
Amusingly, it went around the other way too. When I finally read Notebook Found in a Deserted House by Robert Bloch, which I understood to be the origin of the Dark Young of Shub-Niggurath, I found out they were actually shoggoths (which Lovecraft created) Chaosium made them as the brand new dark young to bulk up t heir bestiary :D And, in turn, authors have used the dark young in stories.
(Notebook et al is a really good story regardless and I’m glad I read it for its own sake)
Seriously, The Call of Cthulhu RPG wasn’t just a game. It was a Wikipedia of Eldritch Horror. And that was just super cool.
(Incidentally, by the time I got around to reading Gary Gygax’s Appendix N, it was more of a checklist of stuff I’d already read :D)