In the mid-80s - i was close to end my school years -, I was playing a postal SF strategy game on regional (Berlin) level, you ruled your galactic empire which you had to built yourself etc: Galactic Civilisation version 0.5, so to speak. You could gain construction points for contributing to the club magazine and writing separate fictional stuff about the power you represented, or write fictional action reports, pretty much the stuff you find in SF fanzines.
I wrote a 60 pages encyclopedia on the history of my faction, including biographies of influential historical fiugures, a 30 or 40 pages essay on the astronomical constellation of my home planet and moons including astronomical history and geology, a small 20 pages booklet on language, and a 50 pages or so catalogue on technology and weapons. Needless to say that Tolkien as well as the two manuals of the encyclopedia of Dune (each of them as thick as the first novel) were my idols.
After I successfully made my audience there to read itself to death, I waited a while and then started to target internet forums a decade later :rotfl:
Oh, and I earned enough construction points to turn the whole galaxy into my private household