Torg was a roleplaying game released about thirty years ago in which earth was invaded by different realities, different genres of roleplaying game, and you played characters from these different realities who all worked together to fight the invaders. Thus, fantasy wizards worked with cyberpunk hackers and two-fisted pulp detectives to defeat dinosaur-riding lizardmen. It was a lot of fun, but never one that I got into in any depth.
In 2017 it was relaunched as Torg Eternity, with new rules and a slightly revised background. The publisher also created a Community Content program, the Infiniverse Exchange, where fans of the game can publish material for it and charge money for them.
Even now, I am not entirely sure why I was so inspired to write by the game. This particular book, the first thing I wrote, was directly inspired by the ending of one of the Day One Adventures. America has been invaded by a primitive jungle reality, and the characters have just managed to escape from New York, to the New Jersey shore. They are seeking sanctuary in Philadelphia, and the book just said “with no further obstacles, the characters reach Philadelphia safely”. There’s miles of jungle in the way! This book takes them through the jungle to Philadelphia.