Adventure scenarios are an indispensable part of all role playing games. Gary Gygax's Insidiae: The Brainstormers Guide to Adventure Writing covers five vitally important aspects of game adventure design: back story, antagonists, motive, locale and plot. Each chapter builds upon the details of the last, teaching the hallmarks of good game mastering. Working through the guide will aid game masters in creating adventures for any role playing game; provide an array of ideas, character types, backgrounds, places of encounter and danger, and plot devices needed to propel characters deeper into the story.