"The original Dark Sun product line was one [of] TSR's most popular releases with an enduring fan following. In the 1990s, fans formed multiple mailing lists, fan sites, and discussion boards concerning the setting. These fan sites grew to such a size and scale during the 1990s that TSR filed legal paper work against them for infringing on their copyright."- Wikipedia on Dark Sun
"[Dark Sun] is so fucked up it makes Mad Max's setting look like a hippie paradise ... The best weapon you can find is the femur of your party's cleric after being eaten by something that looked like a rock and the best armor is mostly the remains of a giant roach."- 1d4Chan on Dark Sun
"Dark Sun is a particularly dangerous place; one where character death is frequent and, at times, gruesome. High PC mortality rates find some relief in the character tree ... Still, as deadly a world as Athas is, player characters, especially those at low levels, may die too frequently"- 2e rulebook on "character trees" a.k.a. having three backup character sheets
"Basically fantasy Australia"- gamerstavern.org on Dark Sun
Athas’ savage, primal landscape is the result of long centuries of ecological and magical abuse. The world is dying. It breathes its last gasps as water turns to silt, grasslands become sandy wastes, and jungles decay into stony barrens. Still, life finds ways to endure even in these hellish conditions. In fact, it thrives. Children growing up beneath the crimson sun don’t aspire to become heroes. True heroes who champion causes or seek to make the world a better place are as rare as steel on Athas. Living to see the next dawn is more important than defending a set of beliefs, so survival ultimately motivates all living creatures—not virtue or righteousness. But heroes are desperately needed in this harsh, savage world...
Dark Sun is different from traditional D&D
Many monsters, prestige classes, spells, and magic items from the core rulebooks simply are not available in Athas. Many races were extinguished from Athas during the Cleansing Wars. This is because Athas has a very different background than most D&D settings.
Athas puts the survival of the fittest concept to its fullest. Those who cannot adapt to endure the tyrannical Sorcerer-Kings, the unrelenting sun, or the many dangers of the wastes will certainly perish. Illiteracy and slavery are commonplace, while magic is feared and hated.
The basic necessities of life are scarce on Athas. This means that every society must devote itself to attaining food and safeguarding its water supply, while protecting themselves from raiding tribes, storms, and other city‐states. This essentially means that most Athasian must devote a large portion of their lives just to survive.
The World is a Desert: Thousands of years of reckless spellcasting and epic wars have turned Athas into a barren world, on the verge of an ecological collapse. Athas is a hot, arid planet covered with endless seas of dunes, lifeless salt flats, stony wastes, rocky badlands, thorny scrublands, and more! From the first moments of dawn, the crimson sun beats down from an olive-tinged sky. Temperatures routinely exceed 40 degrees by mid-morning and can reach 70 degrees by late afternoon. The wind is like the blast of a furnace, offering no relief from the oppressive heat. Dust and sand borne on the breeze coat everything with yellow-orange silt. In this forbidding world, cities and villages exist only in a few oases or verdant plains. The world beyond these islands of civilisation is a barren wasteland roamed by nomads, raiders, and hungry monsters.
The World is Savage: Life on Athas is brutal and short. Bloodthirsty raiders, greedy slavers, and hordes of inhuman savages overrun the deserts and wastelands. The cities are little better; each chokes in the grip of an immortal tyrant. Slavery is widespread on Athas, and many unfortunates spend their lives in chains, toiling for brutal taskmasters. Every year hundreds of slaves, perhaps thousands, are sent to their deaths in bloody arena spectacles. Charity, compassion, kindness—these qualities exist, but they are rare and precious blooms. Only a fool hopes for such riches.
Metal is Scarce: Metal's scarcity has forced Athasians to rely on barter and different materials, such as ceramic, to use as currency. It also hampers industrial and economic development as well; mills and workshops rarely have quality tools to produce everyday products. Even though most Athasians have developed ways of creating weapons and armour made of non-metallic components, the advantage of having metal equipment in battle is huge. Most arms and armour are made of bone, stone, wood, and other such materials. Mail or plate armour exists only in the treasuries of the sorcerer-kings. Steel blades are almost priceless, weapons that many heroes never see during their lifetimes.
Arcane Magic Defiles the World: The reckless use of arcane magic has reduced Athas to a wasteland. To cast an arcane spell, one must gather power from the living world nearby. Plants wither to black ash, crippling pain wracks animals and people, and the soil is sterilised; nothing can grow in that spot again. It is possible to cast spells with care, avoiding any more damage to the world, but defiling is more potent than preserving. As a result, wielders of arcane magic are generally reviled and persecuted across Athas regardless of whether they preserve or defile. Furthermore, very few are able to tell the difference between divine and arcane magic. Only the most powerful spellcasters can wield arcane might without fear of reprisals.
Sorcerer-Kings Rule the City-States: Terrible defilers of immense power rule the city-states. These mighty spellcasters have held their thrones for millennia; no one alive remembers a time before the sorcerer-kings. Some claim to be gods, and some claim to serve gods. Some are brutal oppressors, where others are more subtle in their tyranny. The sorcerer-kings govern through priesthoods or bureaucracies of greedy, ambitious templars, who can call upon their god-kings’ powers.
There are no Gods: Athas is a world without deities. There are no priests, no paladins, and no prophets or religious orders. In the absence of divine influence, other powers have come to prominence in the world. Psionic power is well known and widely practised on Athas; even monsters can have deadly psionic abilities. Clerics attune to a classical element and druids call upon the primal powers of the world. Athas is a world without true deities. Powerful sorcerer‐kings often masquerade as gods but, though their powers are great and their worshippers many, they are not true gods.
Fierce Monsters Roam the World: The desert planet has its own deadly ecology. Many creatures that are familiar sights on milder worlds have long since died out or never existed at all. Athas has no cattle, swine, or horses; instead, people tend flocks of erdlus, ride on kanks or crodlus, and draw wagons with inixes and mekillots. Wild creatures such as lions, bears, and wolves are almost non-existent.