Most Role-Playing Games operate under the principle that there are players and there is a Game Master. The GM prepares all the details of an adventure, and then "runs" the players through that adventure. This usually requires a great deal of preparation on the part of the GM.
Mythic is different in that it requires no preparation from the GM. Mythic adventures are meant to be played off the cuff, with perhaps a few minutes of brainstorming to come up with the initial setup. Mythic can also be played entirely without a GM. The same mechanics in Mythic that allow a GM to run an adventure without preparation also allows a group of players to do without the GM.
In a Mythic adventure, the GM (or players sans GM) can start an evening's entertainment with about five minutes of preparation. As the adventure unfolds, the GM is just as surprised by the twists and turns as the players are.
There are various ways in which Mythic can be used:
No GM, multiple players: Players decide on an opening scenario, and perhaps a few details or two, and Mythic takes it from there. All action is decided through the asking of yes/no questions and the application of logical principles. By answering questions, the adventure moves along, with the occasional random event throwing players a curve ball. The action is broken into scenes, just like in a movie, to keep everything straight.
No GM, one player: Mythic can be used to go solo. There have been many solo systems in the past. But let's be honest, they weren't so great. Solo play in Mythic works the same as group play. You're just alone.
One GM, any number of players: For those who like to be a GM, we have something for you, too. The same tools that allow Mythic to automatically generate adventures on the fly without a GM also work with a GM. This means very little to zero preparation, if you don't want to prepare. Simply create an opening scenario (hey, you can come up with that on the drive over!) and follow Mythic as it guides you along. Mythic will throw in its own twists and turns, so the GM will be just as shocked as the players.
Mythic, stand-alone: Mythic can be played as a complete role-playing game. The same logic-based tools that guide an adventure along can also answer other questions, such as "Did Boltar's sword hit the goblin?" On its own, Mythic is a free-form and interpreted system. Much of the details defining a campaign world will come up as the adventure proceeds.
Mythic with other RPGs: Mythic's main strength is the ability to generate dynamic, unfolding adventures on the fly. Mythic can replace the GM even if you're playing another role-playing game and not using Mythic rules as the core rules for your campaign. Mythic takes the place of the GM, but the main RPG's rules still handle character creation, combat, task resolution and everything else. Questions that players would normally ask the GM are now asked to Mythic, instead.