There are negligible differences in the classes in Dark Sun. However, a few have some significant Differences and there are some that are outright not allowed.
Other classes, such as the additional base classes are also restricted.
Additionally, there are no significant changes to these 4 psionic classes. Other psionic classes are allowed at the GM’s discretion. As for the other core classes, the ones available for this campaign are listed below:
- Cybermage (Wizard)
- Defiler (Sorcerer)
- Obsidian Blade (Monk)
- Psychic Warrior
As a special flavor note, though magic exists, it is in a very diminished state or at least it is for Arcane magic. The majority of “supernatural” people in Athas are instead Psionic. The Templars of various orders are very selective and don’t take too many into their ranks. The Clerics special bond with the elements and elemental planes tends to weed-out quite a few applicants. Druid are even more reclusive and because of the lack of “nature”, i.e. trees, forests, etc, they are few and far between. Bards have no magical ability (see the Bard page). Thus a lot of people lean on Psionics instead of magic.