The Open-Ended Machine is a game framework inspired from the MATRIX game system that aim to allow to adjudicate open-ended games with easy to use mechanics. Easy to use mechanics does not necessarily imply simplistic mechanics, however. The rules are better used as a starting point to design a scenario or a game, and can handle any of the complexity and fine-grained details that the players care to introduce while the game is proceeding. This is done without the need for complex rules and difficult to balance mechanics. However, the game will be as good as the player and the referee put into.
As a result, this system is well suited for both the classroom and the pure entertainment setting. There is, in fact, precedent for both.
How does a game played
Of all participant, one is named the referee. The game could go without one, but it makes things easier if some players are not familiar with the system. All other players are assigned an actor, with proper background and game objective(s). The first actor to act is said to be "holding the conch". The conch holder proposes an event or an action and its outcome. Everyone is then invited to argue in favour or against the outcome. Each independent and significant supporting fact increase the chances by 1, each counter-argument/fact decrease by 2. The effect of these arguments is tallied and added to 10. The outcomes becomes true when the sum of the roll of 3 6-sided dice (3D6) is equal or less than the target number. If the initiative is successful, the same player keeps the conch for the next round. Otherwise, the referee assigns the conch to the player who managed the best to draw the control of the narrative toward him/her.
There is a bit more, but that is pretty much it for rules. The value of these rules is more in the statistical framework than its complexity of implementation.