Here you'll find a pile of free role-playing-game related PDFs.
Many are Creative Commons by Attribution, so you can use the content in
your own games, supplements, etc.
Most are in my blog on game mechanics and ideas for role-playing games
here:
http://epicempires.org/ideas/
You can see some of my released games
on DriveThruRPG at this link:
https://www.drivethrurpg.com/en/publisher/22709/andrew-cavanagh
Read my multiple award winning
Ironborn fantasy novels on Amazon here:
https://www.amazon.com/dp/B0CYWJ7G8J
You can read a preview of the first novel, Ironborn, here...