Adventures Dark and Deep: Game Masters Toolkit (2013)

From back cover:

What if Gary Gygax had been allowed to go through with his plans for a second edition of the world's most popular role-playing game?

In 1985, Gary Gygax left TSR, unable to continue development on Advanced Dungeons and Dragons™. However, he wrote several articles in Dragon™ magazine detailing what the new edition of the game would look like, and in later years expanded greatly on those articles in various online forums and other venues. ADVENTURES DARK AND DEEP™ is an attempt to realize those plans and create the game that Gygax was unable to. This detailed tome is the result of years of research and effort, and provides a glimpse into how a new edition of the world's most popular role-playing game might have appeared if its creator had remained at the helm.

This book has rules, guidelines, and advice a game master needs to create a long-lasting campaign or run a one-shot adventure. Those intending to referee a game or create an entire campaign will also want to purchase the ADVENTURES DARK AND DEEP™ Players Manual and Bestiary, also available from BRW Games.