Recently, the question Whither the West Marches was asked over on the Hill Cantons blog. Interesting question!
To recap, a campaign using the West Marches model described on Ars Ludi had several interesting characteristics, as summarized on the Hill Cantons blog:
My Alder King campaign had started using D&D 3.5 using this model. Player characters advanced up to 9th level, some of them ending up with important positions in towns of the region. We played with a second generation of characters for a while and I still liked it. I no longer liked D&D 3.5, however, and so the campaign switched to the Solar System RPG. When that campaign ended, I started a campaign of Pendragon.
While it lasted, however, the Alder King campaign differed from the West Marches model mainly in that I had fewer players and that we had regular, scheduled sessions. These dates were set by me, not by the players. We had up to seven players at some points in time, but having all of them at the table was rare. In all that time, I felt that there was no regular plot, but I had inserted various modules I had bought here and there, so often the players might have felt that there was a regular plot.
Later, I started my campaign of the Five Winds. This time I have a group of eight players and there are almost always a few of them missing. Thus we’re doing fine with regular biweekly sessions and three to eight players each. The players are not scheduling sessions. In GM Florian’s campaign, same thing: players don’t schedule sessions. Instead, we have regular biweekly sessions. In DM Peter’s campaign, he announces his availability via mail and people sign up using Doodle. Again, that doesn’t feel like players actually scheduling sessions.
Thus, I think the key element I used from the West Marches model was sandbox play: exploring the wilderness, dungeon delving, no regular plot, players defined goals in game.
The Hill Cantons blog posts then goes on to say that the campaign also developed urban adventures. None of the four campaigns I mentioned did that. In my Five Winds campaign, for examples, the towns my players meet continue to be defined by three or four non-player characters and very little else. These characters provide quests, some evil doers or incompetents must be replaced every now and then. Town adventures make up at most a tenth of my campaign.
Similarly, sessions soon started to end outside of town—since I wasn’t running competing parties or at irregular schedules, this never was a problem. We just found lousy in-game excuses for missing or new characters in the party from session to session.
For a short while I was running two parties in the same starting town. It turned out that not ending every session in town wasn’t much of a problem. Flexible time keeping turned out to be the answer: whenever characters return to town, advance the time up to the point where the other party is.
In fact, the current Five Winds campaign soon moved to a travel based campaign: the party moved east, looking for one of the big cities of the campaign world, the city housing the school of chromatic wizards. They keep getting sidetracked by pirates, barrow mazes and the like…