Dark sun advice
My first two games of Dark Sun flopped, then the third ran smoothe growing into a two campaign with two sub groups that branched off, by the time I was done I had over 45 different players through the two years and three game nights and Dark Sun had become my favorite D&D setting. I found that the mistakes of the first was that the party was enslaved, in fact I ran freedom...where they begin as escaped slaves. This was bad because they felt right from the start that they were being railroaded and setup and in turn, it hurt the game. THe second game put to much focus on the environment and desert, lakc of water etc.. it flopped, it was too hard and depressing. The third they were a group of mercenaries brought together by one of Nibenays templars (which are all his wives and they wear less cltohing the higher their rank), she hired the group to go into the forest near the city and exlpore these elven ruins. They hada nice adventure, exploring, learning of some elven secrets from before the current age and then when they found the item she sent them for and were coming out of the ruins, she attacked them with her underlings (lower level templars, milita and city troops). She had framed them as traitors to King Nibenay and they were forced to fight their way back into the ruins, lookingfor another way out...which was in a secret passage lead through mountains north of them and out into the desert, standed together with only the supplies on their backs and noway to return to nibenay. The real secret of this game, besides the way it opened was that the game got very political and some realistic goals established for the party. Eventual they were entwined against three city states, had allies wihtin the veiled alliance and a number of other resistance groups and contacts in numerous villages, merchant outposts and cities. Very good game, wonderful stuff. FOcus on the confilcts in darksun, but I would state that it isn't as brutal as left-wing hummingbird says, it is surivival of the fittest, but not to the extent that societies are not bound together. Smaller tribes, commnities and city sectors trust each other, juts in the city the people are oppressed and played against each other by the templars and the laws of the Sorcerer king (or queen) there. Good luck with your game.
Nate