A 2008 version, extracted from the bay12forums.
The GM (Game Master) posts a situation you, the players, are in. You then post your actions, exactly one action per turn. Once all players have made their actions, the GM posts again, with the results of the actions and the state of the world around you. After which you post actions again, ad infinitum.
The action results are defined by a six-sided die roll:
[1]: Epic Fail. Whatever you tried to achieve, you didn't, and you made it worse.
[2]: Fail. You didn't, or couldn't do what you tried to.
[3]: Meager success: You didn't fail, but you didn't succeed either. Like trying to sit on two chairs but ending up on one.
[4]: Success: You succeeded in your plight. All consequences are now your problem.
[5]: Epic Success: You succeed in the most positive way possible. The universe will bend to your will.
[6]: Overshot: You achieved what you tried to achieve, but you made it worse by doing so in the most inhumanely overpowerful way possible. Casualties are inevitable.
In addition, if at any time something threatens you, you get a free roll to dodge it. If you end up in a very bad situation as a result of the first dodge roll, you may or may not get another free roll to narrowly escape death.
Okay the whole forum is in the game. You all roll to dodge. Rocks fall, (roll-1) everybody dies.