Call of Cthulhu, the amazing RPG based on HP Lovecraft’s horror writing, might be my favorite table top game.
One thing that sets Call of Cthulhu apart from all the other major fantasy table top RPGs is that it is set in the real world and the players are real people. Players get no special powers, weapons are difficult to use if you aren’t trained, you’re just regular people using your knowledge to try and prevent something terrifying and beyond your understanding from taking place. There is some magic in the game but I’ve always shied away from using it because I think it detracts from the overarching themes of powerlessness.
The flip side of this player realism is that as the Keeper (the Call of Cthulhu name for the Dungeon Master) you can actually use your own direct experiences for the game. In all our pasts we have some bizarre events, things that had some sort of logical conclusion but that still scared us at the time. Maybe it was a monster under our bed as a kid, a creaking we hear in our grandparents roof when we visit, a strange howling we heard while camping, or even a classmate in college who disappeared and never returned to school. Whether it be silly, fantastical, or dark and real, as a Keeper you can actually draw from your own personal history to create a world and plot. This is not something you can do in other table top RPGs. You can have similar themes, but not settings, geography, location, events, people, etc.
By drawing on your own past you naturally have a much firmer grasp of events and visuals than you would otherwise. This translates not only in better details and easier writing, but also when you speak of these places there will be a tinge of realism in your voice that is impossible to duplicate and that the players will respond to.
I love Call of Cthulhu it’s actually pretty easy to pick up once you wrap your head around its d100 system. As a Keeper I love taking bizarre stories from my past and turning the truth behind them into something fantastic. I’ll use maps of places I’ve lived, describe buildings I’ve been inside with details only I would know, describe how the air smells and feels, what the people are like, and more. This realness makes the experience that much better and so far my players have always loved it.