Released in 1991, the Dark Sun setting for Advanced Dungeons & Dragons was a revelation. More than any other setting up to that point, it showcased the way D&D could encompass many different kinds of fantasy while still remaining true to the game. It introduced a metal-poor desert world where survival was as much as a challenge as fighting orcs. It provided a new twist on standard D&D races, including tribalistic halflings and desert-running elves. Drawing more from the Dune series than The Lord of the Rings, it showed how broad D&D’s horizons could go.
If you want a great example of the creative energy that infused AD&D 2nd edition, check out the original Dark Sun boxed set. And then, if you want an example of how bad its adventures could get, check out the setting’s first module, Freedom.