The campaign currently coded “Planeswalkers” is one set in a world very similiar to that of the “Magic: The Gathering” franchise. It takes elements from other settings (both Dungeons and Dragons and homebrew) including past campaigns, Oriental Adventures, Eberron, Forgotten Realms and (most prominently) the “Planescape” setting.
First and foremost: no characters from the Magic the Gathering novels and stories will be used for anything more than historical basis. So don’t expect to run into Nicol Bolas, Urza or Jace. The campaign is assumed to take place in an alternate continuity. So, for instance, Alara is still unbroken, but Nicol Bolas is assumed to have been defeated. The planes may or may not be in states consistant with any timeline in any of the stories. Ravnica may be in a pre-guild state whereas Kamigawa may be in the midst of the Kami war. These are only examples. Timelines will remain consistant within the context of this game (i.e. continuity will be maintained in and of this game itself), but this game is set in a world as distinctive from Magic the Gathering’s multiverse as required.
Please note also that although we are using the 3.5X system, players will be given special access to a number of spells making them, to coin a term, “semi-Gestalt”. Essentially, everyone gets a spellcasting list, and spellcasters get two lists. See the wiki for more information on character creation.