Exactly how does it works??
Here is a link to the review at RPG.net. The author gives a good description of how Mythic works as well as an example from his campaign. Rather than rewrite his review, I'll just sum up a few of the main points of the system.
The main driver of the system is the Fate Chart. The Fate Chart is a means by which "Yes/No" questions are resolved. It is a simple, percentile table that determines the odds of an event occuring (from "Impossible" to "Has to be") modified by the current Chaos Rank. It also allows for the possibility of "Exceptional Yes" and "Exceptional No" answers.
The Chaos Rank is a measure of how out of control the world around the PCs is. The higher the Chaos Rank the more likely a "Yes" answer will occur on the Fate Table.
Exceptional Yes/No results are, well, exceptional. They are the perfect answer for PC success or failure.
The second aspect of the system is the Random Events table. Each roll on the Fate Chart has a possbility of a random event occuring (the system details the specifics of this). Random events can include the introduction of a new NPC, the closing of a plot thread, a positive benefit for a PC, or even an ambiguous event whose true nature will be determined at a later point in time. This part of the system relies on the player's ability to interprete the rolls on the Event Focus and Event Meanings (Action and Subject) tables.
For use with D&D, I think that it is best to use random encounter tables (I personally like using D&D mini cards, found
here) and random dungeon generators (like
this one). Use the random dungeons and encounter tables to determine what is there and use the Mythic GME tables to determine why.
Hope that helps!
-JM