As long as the participants want it to, obviously; but I wondered if there were any assumptions built into games. My current face to face group is averaging about three sessions per month, or 36 per year; so how long would a campaign based on a game’s declared assumptions last?
I’ve read that WotC operates on a five-year cycle; their research tells them that gamers have bought all the products they will ever buy for a particular game in the first five years, and after that, a new edition is commercially necessary. So, my expectation going into this exercise is that it won’t be more than five years, call it 250 sessions tops.
I started with D&D 3.5, because while I wouldn’t play anything that complex at the moment, it’s more consistent mechanically than any other game I know. The underlying assumptions of D&D 3.5 are that a PC levels up after 13.33 balanced encounters, and that they pause to recuperate after four encounters. Since a session is intended to be 3-4 hours, that suggests a session will include 3-4 encounters, which feels about right from my experience. PCs can go up to level 20 in the core rulebooks, for a total of 267 encounters, or 66-90 sessions.
D&D 4E assumes one hour per encounter plus one hour easing in and out of the game, levelling up every 8-10 encounters, and a maximum PC level of 30. So a campaign taking PCs from 1st level to 30th will be about 270 encounters, or let’s say 90 sessions. 4E characters level up faster, but have further to go.
What about Savage Worlds? Well, one is encouraged to hand out two experience per session, and PCs reach Legendary rank at 80 experience or 40 sessions; there’s no upper limit to advancement, although I suppose one would eventually run out of advances to take. Looking at the plot point setting books in my possession, I see that Necropolis 2350 has 31 scenarios, Dogs of Hades 30, Savage Suzerain 40, Slipstream 27, and Solomon Kane 28. So 30 scenarios would be a good average, say 60 experience. Most of the setting books have adventure generators and assume that you will create and run your own adventures, to be fair, and there are a number of free scenarios, supplements with extra adventures and so forth. Let’s say that doubles the run, for the sake of argument, and takes you up to about 120 experience – four advances into Legendary, or the beginning of Demigod if playing Suzerain – or again about 60 sessions.
So, a baseline campaign duration for my group would be two to three years under any of those systems. In order of increasing campaign duration, the games are Savage Worlds, D&D 3.5, and D&D 4E. Looks like my off-the-cuff guess of two years in an earlier post fits right in, although an SW game where I didn’t add extra scenarios to the plot point campaign could easily be over in a year.
I expected SW to be the first to finish; the fast, simple combat means groups chew through plot faster than in later editions of D&D. I also expected the D&D 4E campaign to be shorter than the 3.5 one, but that’s not what the numbers tell me; and I don’t argue with the numbers.
Another way to look at it is to say that if an early-adopting group finishes advancing to the maximum PC level over a five year period, they are probably playing one evening every three weeks or so. I’m curious now; how often does your group meet?