Well, ok, not session. Maybe we should find another term, but round is already taken. Maybe "deal", as in cards?
What the hell am I talking about?
Traditionally, a "session" of a rpg determines some indefinite and virtually uninterrupted period of time, a single "sitting" during the which we play the game. It is pretty synonymous with an "evening of play". On the larger scale, sessions tie up together in scenarios and campaigns. On a smaller scale they break down into...well, they don't.
During combat (or some other conflict) we usually have "turns" which build up into "rounds" which often build up into "encounters". I've often seen a complaint raised against D&D 4E in regards to the "time" scale of its Powers. You have your At Will powers, your Encounter powers and your...Daily powers. How many encounters is a day? How do you track days?
When Mouse Guard came out I remember there was quite some confusion regarding its session turn structure (not the same as the aforementioned combat turns). First you have a GM Turn, during which the GM gives the players a mission and beats the crap out of them. The GM Turn is followed by a Players' Turn during which the players are free to pursue their own goals with checks they earned in the GM's Turn. A lot of people felt that that was too short. "We finished the GM Turn and Player Turn in just a couple of hours!" people said. Luke's answer was blindingly, deceptively simple: "Well play another session." Two sessions in an evening...whoa, that's not how we usually think about it.
Next exhibit: Apocalypse World. For some reason whenever we played Apocalypse World I felt that we went through more fictional content in two hours than we did in other games. We played for some three hours and then I'd simply say "ok guys I think that was enough". The first session of Apocalypse World is meant to be somewhat uneventful, because you're still introducing the characters and the MC has not made his Fronts yet. Leave that for the next session, the book says. But you know, why fill the whole evening with that "first session" stuff, it's "uneventful" anyway. Make characters, play for an hour or two. Stop. Take a break. Then play again!
One more: I got the Wrath of Ashardalon a couple of weeks back. Our games took a bit longer than they should because one of the players was dialing in through skype and I was the only one who had read the rules. But we still got through two dungeons in a few hours. I'm sure once we'll be cool with the rules we'll be able to go through at least three in that same time.
When we were in high school sessions of epic length were often conducted. Seven, eight, nine hours of nonstop play were not that uncommon. It was both awesome and exhausting. These days it's an ideal that's practically impossible to aspire to. We all have different schedules, other things to do. Sessions run half that long and less. But you know, why should we fill all our available time in an evening with one single session?
A deal of cards is when we are dealt the cards and play until someone wins. Then we shuffle the cards and play again. We do this many times in an evening. I propose that a "deal" in a RPG is a sequence of play during which something is accomplished. A course, a level, a mission, an episode, a chapter...whatever. It's longer than a "scene" or an "encounter" but it's shorter than the traditional understanding of "session". It doesn't need to be artificially stretched across all our alloted "evening" time (thereby often fluffing the extra time with play where nothing is accomplished).
I can see this having several beneficial effects to how we play in general. Instead of preparing for the whole evening, the GM can prepare shorter, punchier segments and then actually push to action in play, not avoiding a resolution. It would give us an intermediate time frame longer than "encounter" that 4E seems to be lacking. Most importantly, it would allow you to have several sessions in one evening! Isn't that awesome? I think it is. It feels like you're playing more.
So in play, don't pussyfoot about, but get right down to it. See to it that something will happen, something will change, something will be accomplished. Get to the action. And once you've achieved some resolution, stop. Take a break. Grab a drink, smoke a cigarette, shoot the bull, talk about how awesome what just happened was. Take five. Then play another session. If that's not awesome I don't know what is.*
*This is medicinal personal preference, please consult yourself and your players before consumption to avoid potentially harmful side effects. Might not respond well to all games.