From the back of the book: "NO GAME MASTER NEEDED! Mytherian Heroic fantasy is a unique gaming experience. Build your hero using 400+ skills and spells, adventure through 400+ events and features including cities, wilderness, dungeons in an Adventure building system unlike any other. Now available in one mighty hardbound tome, at discounted price, includes everything you needed including the Adventure Setting, the Goblin Skullkeeps of Rendaria."
Players can play fully cooperatively, opposed, or with a GM.