Bastoche said:
If you want to have an "open ended" game, you MUST not have a plot line.
Well, not any well-developed plot lines. But it can be very beneficial to have several metaplots mapped out for the setting.
For example, when I run my Freeport campaign I've got four metaplots going on: The demonic rites of the original Freeport trilogy of modules; an opium war (adapted from the CITY OF LIES boxed set for L5R); a massive slaver operation; and (later) the power struggle resulting from Milton Drac's death.
I didn't have any of these plotted out in any particular detail (with the exception of the first; and that only by virtue that somebody else wrote the modules). But I had some rough notions about the direction they'd take IF THE PCs DIDN"T INTERFERE.
For example, I didn't want the world destroyed if the PCs decided not to bite on the plot hooks for the original Freeport trilogy, so I know that there'll be a different set of heroes who take it upon themselves to stop the world from being destroyed... but they wouldn't do a very good job of it and there'd be an Abyssal rift left open in the wak of the lighthouse disaster. So if the PCs don't do anything with that plot, I know that they'll hear about these young heroes who are distinguishing themselves; hear about their disgrace (say, maybe they could help try to catch them?); and then learn that they saved the city... well, kind of. Now there are devils all over the place.
Of course, in reality, the PCs tend to start getting involved in things. And as the campaign progresses, more things get layered in. Lift a little bit of material from the Focus on Freeport web features; hook it up to a heavily-modified PIT OF LOCH-DURNAN... What happens if they don't take that bait? Well, the demon power grows and eventually decides to spread its operation to the main land... Et cetera.
Which isn't to say that you can't run a campaign completely off-the-cuff. I've done that, too. But there can be a happy medium between "don't prepare anything" and "trying to prepare everything".
You MUST let the player do what they want to do and fill in from there. Impossible to pull off in a "canon" setting IMO, unless ALL the players are VERY well versed in the setting already.
Or none of them are. Or only the DM is.
If the DM wants absolutly to write HIS story with the players improvising the "lines" it must be accepted up front by all the players in which case the more or less are consiously "railroaded". If you want them to all total freedom, writting a "story" up front is a sure way to meltdown and frustrations.
Again, I think you're ignoring the happy medium ground.
Another campaign I ran had a simple hook into it: The PCs screw up badly and unleash a horrible evil. A powerful mage moves in to contain the evil, but he can't actually stop it without three magical seals. He's going to be busy, but the PCs are low-profile, handy, and thoroughly tied up in the business already. There are those aware of the evil who think the PCs deliberately unleashed it, but this wizard thinks otherwise: But if they can't or won't help him out, he won't do anything to help them, either.
Right there you've got a bifurcation point: The PCs are quite free to decide NOT to help. In which case they become hunted fugitives from the secret coven of arcanists who think they're to blame... and also from the demonic forces they unleashed, because (having started things) they're essential for finishing them.
But, more likely, the PCs take the obvious plot hook and accept the campaign premise: The Quest for the Seals has begun.
But even here the PCs have a lot of latitude: They know where the seals are. How do they get there? What do they do once they get to where the seals are? Et cetera, et cetera, et cetera.
Again, there's a huge middle-ground between "having the players do nothing but speak lines of dialogue" and "have nothing resembling a plot in mind when you create the campaign".
On the open ended format, the NPC "becomes" a doppleganger (to the DM only, to the PC he would've been a doppleganger all along!!!) and then the DM pulls out a pre-generated doppleganger and the story ends.
That's actually not the same thing at all. It can be a useful tool to pick up on the theories the players are spinning and using them to fill in the blanks (or even replacing your own plans if their theories are cooler), but there's no reason why a
dominated wizard should suddenly become a doppleganger simply because the PCs decide it must be true.
Justin Alexander Bacon
http://www.thealexandrian.net