From the book:
Lovecraftian Shorts RPG is a story telling game for exactly three people. Once you've sat down with two friends and explained how to play, this game is likely to take between twenty and forty minutes to play, making it an ideal "filler" type game. However if you really enjoy the game and let yourselves go, you can easily double that time.
This game differs from a traditional Role Playing Game in many ways, the most important of which is that it does not have any Games-Master/Keeper/Dungeon-Lord, no single person is in control of the story. Instead all three players take an equal role in creating and describing the story, both the overall plot and the detail in each scene. There will always be nine scenes in a Lovecraftian Short, and each player will take the lead in at least three scenes with the other players adding their smaller contributions. Each scene will culminate in challenge and a die roll.