Required reading for all players! I was going to do the math blog first, but this is important stuff you guys need to understand before it becomes immediately relevant. In this RP system, all the action happens first, then I show up and decide the outcome of anything requiring random chance. I've chosen to refer to this structure as 'retroaction', meaning "action in the past". There's more to it than that, though. The stuff I do is player-gameworld interactions. Retroaction also applies to player-player interactions. Examples to follow.

Retroactive Probability

Any task in a RP that is not of trivial difficulty requires a roll to complete. The translation to retroaction is simple. (If you're interested in the specifics of how probability works in my game system, read the upcoming math blog.)

Player posts an action in which they attempt to do a non-trivial task.
I come by later, and roll the appropriate stat check.
Player passes or fails task, result appears in summary.

Retroactive Conversations

The most common player-player interaction is exchange of dialog. This may happen any time two characters were in the same place at some point during their turns.

Player one posts. She went to locations A, B, C, and attempted various actions.
Player two posts. She went to locations D, A, E, and attempted various actions.
Either player begins to detail the conversation that was had when both characters were in location A. (The conversation is already over, but we're getting the details now. It's a sort of flashback.)

Retroactive Combat

The other common player-player interaction is combat. This is a little more structured. Combat turns should cover about 30 seconds, in-game time. If you try to do more than I consider reasonable in that space of time, you'll be scaled back. If it's a borderline case, you might be subjected to an offensive speed check to help me determine whether to scale you.

Player one ends her turn in location A.
Player two travels to location A and declares an attack on player one. This attack may include as many combat turns as you have time left in your action. Like, if you ran around for 5 minutes, you have enough time for 10 combat turns.
Optionally, player two may spend remaining time somewhere else.
Player one may now respond to player two as a free action, with the same number of combat turns.
I determine the outcome of the fight and post it in the summary.

That's all for now guys, but keep this stuff in mind. You don't have to limit all your roleplaying to your initial action post! If you're confused on anything, IM me.