How much buy-in from the players do you need before you start a campaign?

[Imaginary Number]

Another factor is the length of campaign you have in mind. If it's a 1-year wonder then you need to nail this stuff down going in, but if you're looking at a sprawling 10-or-more-year endeavour it really doesn't matter very much because you'll have time to touch on all those archetypes and more, should you and-or the players wish to do so.

For example, all three of the examples you give could be done in my current world should the players so choose; along with arabic-desert style adventuring, norse-arctic stuff, underdark crawling, inter-planar travelling, and even space-based adventuring; all to go with the Greek-themed adventuring and CSotIO*-evil-empire-bashing they've done thus far. Which of these they'll actually end up doing is of course still an open question.

I agree that length of campaign is a factor; the more sprawling your vision, the less likely that the players will want to stick to a single adventure archetype. My guess, however, is that 10-or-more-year campaigns aren't that common these days. And, even for a campaign that long, I'd still like to have some player buy-in for the starting point of the campaign even if it's understood that the campaign will wander off and develop organically afterwards.

I also agree with the point about having a campaign world big enough to accommodate the players' interests. The examples that I listed actually all took place in different parts of a homebrew setting that I put together in 1988 or 1989, and the inspiration for most of those examples came from adventure hooks that the players didn't bite on from a prior campaign. I still have some white space available in case the players come up with something I haven't fit in there yet.

 

[Stoat]

I come up with a few ideas I'm interested in and put it to a vote.

Last time my thoughts were:

You are colonists in a jungle wilderness. (Like Farshore in the Savage Tide AP)
One of you just inherited a Castle!
Pirates!
Just before the campaign starts a portal opens and demons pour out.
The people of St. Dismas are going on crusade.
An ancient Eladrin hires you to journey to the North Pole.
Desert theme.

The players voted, there was a tie, and one of them wound up inheriting a castle in the jungle.

 

[Barastrondo]

Barastrondo, I'm loving your posts. You're not going to force me to actually start thinking kindly of White Wolf are you?!

I wouldn't be a White Wolfer if I weren't subverting something, and a negative perception of my company is good enough for me!

(It's actually kind of ridiculous how many fantasy geeks are actually employed here. Both the people I directly answer to are Robert E. Howard geeks, I can talk Clark Ashton Smith & Leiber with half the dudes in my discipline, and one of the new hires was delighted when she found out the D&D game we were inviting her to was based on Renaissance Italy, one of her favorite inspirations.)

I agree that length of campaign is a factor; the more sprawling your vision, the less likely that the players will want to stick to a single adventure archetype. My guess, however, is that 10-or-more-year campaigns aren't that common these days. And, even for a campaign that long, I'd still like to have some player buy-in for the starting point of the campaign even if it's understood that the campaign will wander off and develop organically afterwards.

In D&D in specific, I generally try to plan for something around the length of a five-level block of play: try to go for five levels worth of adventure, which is usually enough time to get in a wide variety of adventures, explore a good chunk of the setting, and beat a recurring master villain in satisfying manner. If the players are still interested in the campaign by the time we're done with that, let's try for another five-level block! It seems to be the magic number for me; right now I'm looking at the first level-six adventure to start a new chunk of campaign as next week's adventure, thanks to everyone being very enthusiastic about the game in question.

 

[Hussar]

Depends on what I'm running.

For example, when I did the World's Largest Dungeon, I was pretty careful to pitch it to the group and make sure everyone was on board before things started. My bunch are pretty open minded, so, it's not that difficult.

For the past year, we've been game hopping, and campaigns have generally only lasted about 6-12 sessions (not really full campaigns, more vignettes) so, other than dropping the basics on the party, not a whole lot of buy in was necessary. Everyone was groovy with the idea of bouncing around games for a while.

We seem to have settled on D&D again for a while, but, we're rotating DM's between adventures, so, again, buy in is pretty minimal - don't like what's going on? Wait one adventure and something new will be on the offing.

Have no idea on what to do for a longer campaign. Nothing's really popping into my brain, so, it's going to be short games for a while more.