I’ve been playing running games pretty frequently (sometimes almost every day), for the last 6 years and I not only almost exclusively use my own content but I’ve almost created a new game. I use many non-my this creatures and create my own creatures as well. I heavily modified magic and changed how sanity worked (often I played with one person, and I couldn’t have them going crazy all the time and getting regularly killed). I crafted a free world filled with things waiting to be discover. For example, I always have the world controlled from the shadows by a man named Kane. He’s the first homohomosapian and also the first Vampire. As vampires get stronger with age, Kane is the strongest possible being. He controls the world with a company called Ergot and often times the players end up running into them.