So this has come up for me before with other FFG products. Most tabletop games assume a live, around-the-table format and thus some abilities or mechanics are available a certain number of times a session, or generated at the beginning/end of a session.

This is pretty easily applicable to chat games too, with a session ending when the players are done being IC for the night or whatnot.

But how do you guys handle it for PbP? I'm about to start running a PbP game and trying to determine how long a "session" should be for purposes of how often I do Duty and Force Point rolls. There are really 2 options: time-based and milestone-based.

For time based I'd pick a certain amount of time elapsed in IRL and say that is a "session." I would probably say a session would last about 2 IRL weeks of time in that case.

For milestone-based I'd look at the overall plot of a given mission and break it down into different pieces based on story climaxes or the players accomplishing certain goals. Whenever that occurs, the previous session would end and a new one would begin, with new Force Point rolls, etc.

How have you forumites handled this in your PbPs? Which seems to work better for you? How would you tweak it?

For the PbP game I run, a "Session" is an entire thread. Most of the time I have a piece of story I wish to tell. In real-life terms, this would be a session of game so in PbP terms, it's not any different.

Make sure you further detail what constitutes as a "Scene" and an "Encounter"

My players were surprised how long it actually took to complete an "Encounter" via Play-by-Post. But I feel that's the nature of the beast. You get to play whenever it's convenient, and you get the chance to take time to think about how your PC or NPCs would react to certain situations. But it definitely has the chance to take months to complete a session, based on the frequency in which your players post.

Best way would most likely be milestone based. Time runs the risk of pressuring players if a "deadline" is approaching. I'm in a PbP of Beyond the Rim right now, and we kind ground to a halt with Thanksgiving, Christmas and New Year's. We've accomplished more since January 2nd than we did in pretty much all of December just with having people around and not visiting family. Our GM meant to have a "session end" about halfway through "Chapter 1" of that adventure, but forgot to make the post for it, so we've only had a Session Break when we left The Wheel. We all had something like 100+ XP to spend. But yeah...just think about how much an "average" group would accomplish sitting around a table. Maybe 1 big combat and 1 big non-combat encounter, plus all the attendant roleplay banter and "prep work" skill checks that would go into such a thing.