OK, so I raised this in a thread about solo dungeon generation because it relates to being able to play any role-playing game solo. Some people use it for wargames too apparently, although I haven't but see how it could.
So I start with what is it?
It answers Yes/No questions
It generates Random events with the use of evocative words
It changes and creates different 'scenes'
It tries to make the game more chaotic as the adventure progresses
It uses percentile dice
It is system and genre-less
How does this work?
You take an initial setup, this can be player made or generated by interpreting the random words.
You 'Set the scene' from the initial setup to start, then through logic choices later on. You check to see if the scene starts as expected, which it can or it can be Altered or Interrupted by another scene. So if you start at the cave of a dungeon it might be altered (say you are instantly attacked), or interrupted (you might get lost before you reach the cave).
Anything you are unsure of, that you cannot resolve with your ruleset, ask a Yes/No question to. Is there a door? Does anybody enter? However, 'do they hear me shuffle past,' is not a valid question if you have stealth rules in your game for instance.
While answering these Yes/No questions the Emulator spits out Random events (based on rolling doubles), first you check who it relates to (PC negative say), then generate the two words (say Mistrust Hope). With these three bits of information you then interpret it for your game 'The light at the end of the corridor turns out to be a very small window with heavy iron bars'.
At the end of the scene you determine if the PCs had the best of it or not, and increase or decrease the Chaos Factor accordingly which affects the likelihood of Yeses, Random events and the Scene not started as expected.
Does it work?
Yes it does, surprisingly. You need no forward thinking of plot, just logical questions that come from the story so far, and the events change things surprisingly.
However for it to work well, I recommend a well thought out character with goals and motives, as these can be picked up by the 'Event focus'. An idea of your game's setting, like no Orcs in Altdorf, maps come in very handy. A name generator like the incomparable The Everyone Everywhere List, or a long list of ready to use names. To hand stats for likely opponents. Scrap paper/record sheets for recording the necessary lists (NPCs, places, plot threads, that sort of thing). I would suggest generally your rules with have 80% of this information anyway.
Well, as I used it more I became more and more aware that I have to roll percentile dice three times to generate a random event, now I don't know about you, but percentile dice are real bummers to read and roll I find, certainly not as easy as d6 or d12 etc.
It takes a while 'to get,' the creative juices need nurturing at first, but before long you are on a quest for Countess Emmanuelle to find the Ancient Tome of Nagash while trying to find your long lost sister.
It's one of those topics that evokes 'nerd rage,' post about this on RPGNet and you'll get 50% reasoned responses and 50% I don't get it, it's not role-playing, therefore you must be the anti-christ, burn the heretic etc. While the rest of us are having fun playing exactly what we want.
Because Mythic is ultimately just a Yes/No generator with added Random events it seems like it shouldn't work, but give it a chance and you will realise that it does, and then when your thief is suddenly grabbed by the local Mafia/City Watch/NYPD/Superheroic do-gooder you will be just as surprised as your players would be, and being able to do absolutely anything once again, rather than turning right and falling down a mine shaft will feel pretty good.
If you want to test drive it, there is an excellent online version here: