"...from Arcadia to Pandemonium, from the plane of elemental Fire to the Astral plane, vast new worlds of adventure are now open to players."
A vital source book for players and DMs of all levels of experience, the Manual of the Planes details the manifold worlds of the known planes of existence. This book describes the inhabitants, rulers, and environments of these worlds, as well as rules for movement, survival, combat, and spell use in these alien surroundings. A different style of AD&D adventures awaits!
Manual of the Planes (1987), by Jeff Grubb, was one of two AD&D hardcovers released in 1987. It came out in July, a month before the year's other hardcover, Dragonlance Adventures (1987).
Needed: New Hardcovers. After the publication of Unearthed Arcana (1985), AD&D had a pretty complete set of alternate Monster Manuals and alternate Player's Handbooks. However, the hardcovers were crucial to TSR's business - and had in fact helped save the company in 1985. So the question was, what next?
TSR decided upon a pair of books about rules for the two most common adventuring environments: the Dungeoneer's Survival Guide (1986) and The Wilderness Survival Guide (1986). After that, it was probably a small jump to the idea of a book about the planar adventuring environment - which was sort of a combination of those earlier Survival Guides with Deities & Demigods (1980).
(The upcoming release of second edition AD&D was probably also a factor, as a book like Manual of the Planes could remain relevant even under a new edition of the game.)
Expanding the Outer Planes. The Great Wheel of Planes first appeared in The Dragon #8 (July 1977). It was refined in the Player's Handbook (1978) and Deities & Demigods (1980).
In the early days of D&D, the planes mostly acted as a source of enemies - like demons, devils, slaads, elementals, daemons, and more. There was talk of publishing adventures set in the Plane of Shadow and even about creating a whole series of planar adventures related to Greyhawk, but because of Gary Gygax's creative role in many of these adventures (and because of his increasingly busy role as a manager at TSR), they never appeared. Instead, players' first chance to adventure in the planes was in "Q1: Queen of the Demonweb Pits" (1980), which took them to the Abyss. TSR would return to the planes (sort of) in T1-4: The Temple of Elemental Evil (1985).
Meanwhile, Dragon magazine started covering some of the planes in more depth. Roger E. Moore wrote about "The Astral Plane" for Dragon #67 (November 1982), then Ed Greenwood covered "The Nine Hells" in Dragon #75 (July 1983) and #76 (August 1983). Despite their in-depth coverage, these major pieces on the Planes were very piecemeal; there was no overarching plan for the planes of D&D other than a few increasingly old drawings.
Needed: Clarification. The original goal of Manual of the Planes was to simplify and codify the scattered material on the Planes, by now written by a variety of hands at a variety times - particularly including rules on how spells worked on different planes. As Grubb wrote the Manual, however, it became more of a "guidebook for survival and adventuring", but one that still referred back to everything that had come before.
The Cover Critter. In Dragon #142 (February 1989), Skip Williams revealed that the monstrous critter on the cover was an "astral dreadnaught, an as-yet undescribed monster that inhabits the Astral plane." Grubb also mentioned the mysterious creature in Dragon #120 (April 1987). It sadly wouldn't be detailed in 1e days.
Outer Planes Support. Manual of the Planes is mainly a location book, describing the various planes, delineating how spells work, and - in the style of the Survival Guides of 1986 - talking about how to survive there. Other than a few monsters, there's very little crunch and there's no support for GMs who want complete adventures instead of encounter tables.
Grubb planned to publish that missing crunch through a new "Plane Speaking" column in Dragon. However, he only ended up writing three entries, for issues #120 (April 1987), #125 (September 1987), and #128 (December 1987). Adventure support came through the OP module series, but only one of those was published, "OP1: Tales of the Outer Planes" (1988).
Future History. Despite minimalistic support in the first edition era, the idea of planar adventures has been wildly successful from second edition onward. It most notably spawned the Planescape (1994-1998) setting and a new Manual of the Planes (2001) for third edition. Grubb remains credited as one of the creators of that 3e book (while Moore and Greenwood are still credited for their Dragon work).
D&D4E totally reinvented D&D's cosmology, then published its own Manual of the Planes (2008), which was followed with more in-depth books on some areas.
About the Creators. Jeff Grubb did a bit of everything at TSR over the years. A few years later he'd author Spelljammer (1989), which would be a totally different sort of plane-hopping setting.
About the Product Historian
This history of this product was researched and written by Shannon Appelcline, the author of Designers & Dragons - a history of the roleplaying industry told one company at a time. Please feel free to mail corrections, comments, and additions to firstname.lastname@example.org.