The concept for this campaign is very much the opposite of the previous one I described. Unlike the previous campaign there is a plot, and it's very much routed in the Gygaxian tropes, though I am also mixing things in from my favorite fantasy worlds and taking things in my own direction. It's like an adventure path, but of my own creation.
The basic plot is taken from the first Final Fantasy game. However I'm putting in my own ideas. For instance, though I'm taking the idea of having four elemental crystals, which are the primary objective of the campaign, from Final Fantasy. However these crystals are in fact the power sources for four regulatory stations, ensuring that the forces of chaos cannot corrupt the world. These regulatory stations are magi-tech, built by the ancient Titans during the age when they colonized the world. However they have been compromised by the minions of a renegade Titan that wants to throw the world into chaos.
I've taken inspiration from this post by James Maliszewski about the Masks of Nyaralothep scenario. So I have come up with an initial scenario (though I've yet to write it out completely) leading them into the overall campaign, which will lead to the other scenarios. However, as with Masks of Nyaralothep the exact order in which these scenarios take place will not be predefined. So they might choose to go after the Water Crystal first. However, it may prove difficult to overcome the obstacles of certain scenarios if they aren't of a certain level. We'll see how this experiment works. There is also, of course, no expectation that the PCs will survive the challenges that they face. They may fail. I'll have to consider how I'll deal with that. If the PCs all die what happens? I am considering allowing them to choose PCs based on who they have encountered and what they have done. So if they befriended the King and he hasn't heard from them in a while, maybe he'll have his court wizard cast a divination. Then once he's learned the original PCs have died, he'll send a new party. Perhaps they'll even be able to retrieve the bodies of the original party and have them raised!
I have to admit, I have some doubts about this. This is far from the sandbox scenarios advocated by the OSR, though I am approaching it from a position that railroads are bad and that many of the attempts at doing plot-based gaming have been flawed. But I love epic stories like those in the Final Fantasy series and the Dragonlance novels. I want to run stories like those, I even want to run the Dragonlance modules, though they represent a lot of what is wrong with the story-based playstyle. But ultimately I think this campaign will be fun and isn't that what really counts?