Dark Sun must be kept very different form usual campaign settings or, you destroy what made Athas a great place to play in!
*NO* dragonborn or tieflings at all, unless DM has them somehow come through a planar gate, and note, Dray are
not dragonborn, almost no one who has seen one has lived, they do
not wander across Athas, ever.
Read up on 'emm and see why

Dray hide out in Draegoth's underground realm.
Again, Dark Sun is different, making it "blend into officialnormal 4th ed D&D" would ruin it, mak eit bland, make it...non-profitable
Dark SUn is harsh, hard, deadly: TOUGH. DEAL WITH IT! That's what makes it such a fun place!
Using smarts, people skills, running away!! are damned good ideas in Athasian campaigns,
this should be emphasized.
Ok, how to make Athas for 4th ed:
Stick to original boxed set, let most of the rest rot/be ignored, as much of it was garbage after that point (like whacking half the bloody Sorceror Kings in 2 RL years, ridiculous waste of prime part of the bloody setting!)
Duen Trader and some others add-ons had really nice stuff, but ignore "The Last Sea", "Dragon Kings" and so on, I know some folk love 'em but they are
poison for the setting, they take it into "silly-over-powered-explaining-too-much-mystery" realms. Seriously.
1) Only the official,
original races should be emphasized, rules for Pterrans etdc as side notes or whatever, as they should strongly be discouraged from play to begin with...why? Athasians tend to
eat pterrans, for starters

It' snot wrong to play different Athasian races, but, folk have got to get used ot the idea thatthey are not "human rules laywers over powered quisinardes"...liek thw afore mentioned thri-kreen
The RP aspectsof the races are really important. Like halflings' cannibalism and no sense of greed.
Half-Giants have
got to be
large creatures, end of story, read their description: 10' tall 1,500lb behemoths, but pretty thick and naive.
You cannot change that, or they are merley "big humans", totlaly the wrong thing to do for Athasian games.
Everyoen knows half-giants cna beat the tar out of most folk with ease...but they are thick as cow-flop and thus fall prey to congames and psionics.
I know 4th ed avoids ECLs and penalty stats, but I'd give them +6 Strength/Con, -4 int/wis/cha, Large size, no racial abilities.
Their alignment change didn't make too much sense as presented in original rules really, as it's an RP aspect, they only change *when they have good reason to*, by the example of folk they admire. So, they'd change over time or impressive event etc.
2) Ditch the concept of the "gladiator" and "templar" classes, never made sense anyway, those are
professions. It's a job, not a D&D class
However, adding rules for Templars burecratic powers, and gladiator fame/infamy would be very good.
Note those two things are
not directly linked to "D&D levels" and should not be.
The devious templar with a modicum of spell casting power, but who's a "braniac" with an army of spies is probably more powerful in reality, than an 18th level templar who's a loner.
Templars are servants of ther sorceror-kings, and are usually
clerics, the SK's are like gods to them, thus they have
cleric powers..simple easy end of that worry.
Treat templars as clerics. But give them different paths: power, control, evil, war, bureacracy, law...those are their routes.
THough note many templars are bureacrats, experts, spy-masters etc. Less about how high a level spell they can cast, more about being devious, dangerous SOBs with guards.
So, paragon paths and feats reflecting that would be good!
Gladiators are just arena combatants of *any* type. Making a pargon path for pit fighter, retarii, bestiarii, psionic area fighter etc be cool too.
3)
Defilers are more powerful than normal wizards, end of story!!
The defilers have beaten the preservers , because the SK's, who are uber-defilers,
rule.
So defilers should get powers/feat that make them more powerful, but pay the price in destorying life,
and being marked for death, as everyone hates defilers and kills 'em on sight if they can (an RP issue)
-It never made sense that Athasian arcane magic was tied ot life, ie, preservers can cast all day in a desert...explain that one, with almost no life!

Doesn't make sense, does it?
So, remove that concept of "arcane magic uses life force", instead, reinforce that defilers
leech the life out of things to
bolster their arcane powers.
Big difference, and that change solvesall the concerns: defilers stumbled upon a "cheat"...the reaosn this doens't show up in otherworlds is it rquires the presence of psionics too (either in the world,or limit defiling to wizards who take psionics as multiclass feat?)
IIRC someone suggested Defilers get an encounter power that by
"defiling as a minor action, lets them regain a daily or encounter power but at the cost of damaging plants aorund them"
Something like that be great.
4) The mechanics need to encompasse non-standard materials, like obsidian spears, chitin scale mail etc.
As I explained to someone elsewhere, you cannot and must not "
make non-metal weapons as good as metal weapons, and make metal wepaons better!",
sigh
if you do that, you unbalance the whole game's mechanics. Athas is weighted AGAINST you as a player....good!
Tough, deal with it, enjoy it!

Makes finding steel weapons the treasures they should be.
Many items I think could be made as good as otherworlds', using psionics, and crafting techniques/materials that have evolved over millenia, or materials that don't exist elsewhere (agafari wood for example).
So, you could have steel equivalent items, but not common and costly.
Example: "Braxathide Plate Armour"
Easy to say this as a rule:
non-metal weapons that would otherwise require metal, sufer a -1hit/damage/-1AC penalty.
Notes in equipment tables would show which ones require metal, like swords, halberds, axes, etc. Spears, arrows and daggers with flint/obsidian blades work perfectly well, as opposite examples.
Obsidian weapons should get a +1 damage
bonus, as that stuff's horrendously sharp, eek!
5) heat exhaustion rules as per disease tracking!

different tracks for different extremities of heat/silt/dust.
6) Sorceror Kings should be demi-god or higher in power. Players should not be able to harm them until high in upper tier, ie lvl 25+.
SKs = true terrors!
And the Dragon...Dragon shuold scare everyone

Make it
almost unkillable by a lvl 30 party.
7) The Elemental Chaos works *perfectly* for Athas!

the Abyss did have links ot Athas (it's how two players in my campaign escaped to Sigil...long story). As other snoted, examples of demons and planar gates arein Athasian lore (bringing githyanki in was a bit too much IMHO, though)
having the elemental chaos be accessible is great, though I would make it more difficult than normal, especially to escape Athas (sort of Ravenloft-like).
8) Tweak cleric paths/powers so the 4 elements are large part of it.
9) Make an actual "desert RANGER" class, current 4th ed "ranger" is more of "light armour high damage" fighter, where as, in Athas, survival is a bloody important skill!!
ie, the tracking/wilderness type skills need plugged back into that class, or a new class?
10) Psionics book for D&D has ot be out before or during Dark Sun release. Psionics is absolutley essential to Dark Sun.
11) In my Dark SUn games, I had it that the history was very mysterious and mostly lost in legend and myth, but that the mind lfayers had tried ot darken the Sun, screwed up, sent the Sun into a nova-cycle.
The gods stopped that, but resulting cataclysm still wrecked the Astral plane severing Athas from the Planes and it's gods.
All the psionic powers are a result of the mind flayer's meddling in aeons past (to make a source of energy to tap).
This not only makes a lot more sense than the flop that is the official history

, it works with other D&D lore, lol.
So, erase the "official" histroy completely, it just
suuuuucks. Have the history of Athas a total mystery, or as I had it. Nic big "retcon", let DM's do what the heck they want wth Athas!
having the "true" history of Athas known, ruins the mystery.
STOP ruining the mystery!!
This is a general note to game creators and DMs. No mystery, no "Unknowns" = no fear...
that's my 2 cents worth
Ps, I'm no Brom, but they can use my artwork if they want!
