You need two players (any more will bog it down), lots of index cards (at least sixty for both players), and a few pens (or pencils). From there, basic Magic: The Gathering rules. As you play cards, you draw what they are, filling in all the relevant (and irrelevant, for fun) details. Keep things reasonable, as if they are cards that Wizards of the Coast may actually print, which, admitingly, could be damn near anything, but the goal of this isn't to win anyway.
I call it "Magic: The Development".