From the back cover: "De Profundis is a radical GM-free role-playing game of modern and 1920s horror in the style of H.P. Lovecraft. It can be used solo or with a group. Written in an atmospheric and immersive style, this book contains all the information you need to enter the game’s disturbing world, as well as a description of psychodramatic role-playing techniques." De Profundis is played by sending each other letters written in a Lovecraftian style. The players mutually build a world and create a narrative.