These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Complete Monster: Borys "Butcherof Dwarves" of Ebe is a former member of the Champions of Rajaat, a cult of genocidal lunatics who attempted (in many cases sucessfully) the complete extermination of all non-human sentient races by using the environment-raping defiling magic and turning the world of Athas into a warped desert dying world. He later betrayed the Champions and their master, absorbing them (and killing a city in the process) and turning into a dragon-like Eldritch Abomination.
Critical Research Failure: See Fanservice on the main page. As anyone with any knowledge of survival would tell you, due to sunstroke and dehydration, you want to wear more clothes in the desert, not less.
Fanon Discontinuity:The true prehistory of the world was detailed in Dark Sun Revised edition. Many players just ignore the whole damn thing and continue on with Athas 1E. To wit:
In the beginning, Athas was a paradisical water planet, populated by supergenius biotech using halflings. But then they did something wrong and some brown algae thing was spreading out of control and covering the planet. They did something to fix it, which made the blue sun turn yellow, and turned the water planet into Traditional Fantasy Planet. They then were mutated/transformed themselves into all the standard fantasy races because of it. But there was one mutated biotech halfling, Rajaat, who longed for the way things were, so he invented magic! (Up until this point magic did not exist, it was all psionics and super biotech).
Rajaat then took a group of humans and taught them magic, telling them to wipe out all other sentient races but them. But it was all a trick—what he really wanted to do was kill all races but the halflings, restore them to their previous state, and then restore super halfling biotech world! (How Rajaat even remotely thought he would accomplish this by inventing defiler magic and unleashing a cadre of super-defilers is never explained). So the Cleansing Wars rage on for a while until the Champions of Rajaat figure out a screw job has been going on, and so instead of completing the genocides fully (some races have been wiped out though), they then seal Rajaat in a prison dimension and the mightest of them becomes the Dragon of Tyr while the rest become the Sorcerer Kings. By this point the world is the blasted wasteland of Athas that we all know and love. The End
The story changes in the Dragon magazine 3E revamp were also mostly ignored—it skipped forward several centuries, added a few new dragon-kings, and brought in the maedars (a race of Emo Teens).
The very existence of the Mind Lords of the Last Sea is another piece of 2e Athas that many fans do not acknowledge.