The major D&D campaign settings (not counting one-offs produced for Dragon Magazine) were (in roughly chronological order):
- Blackmoor (1975), the home setting of co-creator Dave Arneson's games. A generic medieval campaign but with a Renaissance level of technology brought about by the discovery of a crashed spacecraft.
- Greyhawk (an adventure in 1975 and then a full boxed setting in 1978), the home setting of co-creator Gary Gygax's games. A generic medieval fantasy world, noted for its frequent wars.
- Mystara, the setting of the D&D Basic game, introduced in 1980. Blackmoor was later retconned into being part of this world. Mystara itself resembles the Earth of some 150 million years ago and is a hollow planet, with a whole other world on its inner surface accessible by tunnels at the poles.
- Ravenloft, a non-traditional setting invoking a sense of gothic horror and dread. Introduced as a single adventure in 1983, but later expanded to an entire world of darkness (cough), undead races, vampire rulers and general unpleasentness.
- Dragonlance, introduced in 1984 as D&D's answer to The Lord of the Rings, a world riven by a struggle between good and evil in which the players were heroes out to save the world. Gave rise to the multi-million-selling novels by Margaret Weis and Tracy Hickman.
- Kara-Tur was created in 1985 as the setting for the Oriental Adventures line of products which introduced martial arts and other eastern ideas to the D&D game. The setting was later retconned into the Forgotten Realms world.
- Lankhmar (originally published in 1985) is, perhaps surprisingly, one of only two officially licensed D&D settings. Based on Frit Lieber's Fafhrd and the Grey Mouser stories, it is set on the world of Newhon and principally the city of Lankhmar.
- Forgotten Realms is the most popular D&D setting. Originally published in 1987, the setting is a high-magic, highly-detailed medieval fantasy world which has become the 'default' D&D setting, despite some changes to the basic D&D rules. The Realms have continuously been in print since 1987, making it most closely-supported setting for the game, and have given rise to the best-selling Dark Elf series of novels by R.A. Salvatore and Baldur's Gate, Icewind Dale and Neverwinter Nights series of computer games from BioWare and Black Isle/Obsidian.
- Spelljammer, introduced in 1989, is probably the barmiest D&D setting, featuring sailing ships which can cross the interstellar void to other worlds. A mixture of high magic, medieval weaponry and retro-space opera, the setting was not commercially popular but has legions of diehard fans who liked its craziness.
- Dark Sun (1991) is sometimes regarded as the most approachable of D&D's 'non-traditional' settings. It is set on the post-apocalyptic world of Athas, where a vast magical war has transformed the planet into a baking desert world gradually being swallowed by a vast sea of silt. Magic as is known elsewhere in the D&D multiverse does not exist, with 'defilers' instead drawing on the life-force of living creatures to create magical effects. There are also no gods, and psionic powers are preferred over magical ones. Despite strong rumours they were considering it, Wizards of the Coast mildly surprised the fanbase when they recently announced that Dark Sun would be resurrected for the new 4th Edition of the game.
- Al-Qadim (1992) is an Arabian-flavoured D&D setting, featuring genies, scimitars, corsairs, evil viziers and other Arabian Nights-flavoured elements. Set on the continent of Zakhara which was officially located in a remote part of the Forgotten Realms world, Al-Qadim has built up a strong fan following over the years but has been largely ignored since the late 1990s.
- Masque of the Red Death (1994) is another horror setting which uses the rules laid out in Ravenloft, but rather than the Demiplane of Dread the setting is 'Gothic Earth', an alternate-history version of our own world in the 19th Century incorporating magic and non-human creatures.
- Planescape (1994) was not a new setting as such, but a setting developed out of the multi-dimensional cosmology that D&D had been using for over a decade and a half by this point. Featuring numerous factions and ideological concepts, the setting attempted to move vigorously away from the traditional elves 'n' orcs of many of the other settings in favour of something new, a setting that challenged many of the underlying ideas of the whole game and forced players to confront the ethical realities of their decisions. The setting also favoured roleplaying over combat. With a unique art style not shared by any other D&D product, the setting was a massive critical and artistic success but proved to be somewhat on the highbrow side of things for most players, and did not sell as well as could be hoped. It was soon discontinued, but later gave rise to one of the single greatest computer roleplaying games ever made, Planescape: Torment.
- Council of Wyrms (1994) was a very short-lived setting which allowed players to control dragons as player-characters. Despite a strong concept, the limitations of what a dragon can do compared to a human player outside of combat soon presented themselves and there were no expansions, although it was briefly reprinted by Wizards of the Coast in 1999.
- Birthright (1995) was another 'traditional' cod-fantasy setting, but had a unique spin to it: the players are painted as the rulers of a powerful kingdom or faction, and between quests have to deal with the day-to-day running of their kingdom and its place in the world, fighting wars and dealing with economic factors. Essentially a D&D campaign crossed over with a board game. The split focus proved challenging and the setting was later abandoned, but interestingly some of its ideas, more cohesively presented, have found their way into the two later Song of Ice and Fire roleplaying games by Guardians of Order and Green Ronin.
- Rokugan (2001) was a second Asian-themed fantasy setting, licensed from the Legends of the Five Rings roleplaying game. It was used in the Oriental Adventures book published for D&D 3rd Edition and several associated adventures, but was not expanded upon, and the licence later reverted to the creators.
- Eberron (2004) is the newest D&D campaign setting, introduced specifically for 3rd Edition and featuring a traditional world with somewhat more advanced technology than is standard, including magical robots ('warforged') and some elements of industrialisation. The setting has proven fairly popular and is the official setting for the Dungeons and Dragons Online computer game.
At this current time, Wizards of the Coast are continuing to support both Forgotten Realms and Eberron through new products for the 4th Edition of D&D. It has been officially announced that Dark Sun will be resurrected for 2010, with a strong chance that Dragonlance will follow in 2011 and Greyhawk for 2012. Planescape and Ravenloft have been absorbed into the base cosmology of the D&D multiverse and will apparently appear as adventures and as asides in the rulebooks, but probably not as fully-blown campaign settings in the future.
Hopes that Mystara, Spelljammer and Birthright will reappear seem somewhat premature so far, but if the new version of Dark Sun is a big success it is possible we will see other settings revisited. The new 4E business model is also more favourable to these old, less commercially popular settings. In the old days, TSR would release a boxed set featuring the setting and then follow it up with lots of expansions, adventures and novels. The new model instead only has three products released for each setting: a general campaign book, a player's guide and a single adventure. Other material is then released online via the D&D Insider website, based on the sales of the physical books.
Future instalments of this series will visit some of these individual worlds and finds out what made them tick, what made them work (or in some cases fail rather badly) and whether we will see them again in the new edition of the game.