Okay, let's accumulate the ideas we have so far, and maybe we can have everyone pick a preference:
1: Standard 'continuation' story, ie, one person writes the first chapter, another person comes along and continues it in the next, and so on and so forth.
1-A. Standard 'continuation' story, with limited characters.
1-B. Standard 'continuation' story, with unlimited characters, or one character per author.
1-C: Chapter organization: First come, first serve, ie. taking 'dibs' on the next chapter.
1-D: Chapter organization: Assigned chapters beforehand, ie, saying so-and-so will write chapters 1 and 7, while such-and-such will write chapters 3 and 9.
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2: Roleplay story: Each person controls one character, with no limit of who can post when, to continue the story, although individual writers will have less control over the overall story arc.
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3: Story challenge: A plot-basis and maximum story length will be chosen beforehand (ie, write a 5 page story about meeting Bono in a bar), each author will write and submit their version of this story by a certain date.
I think that's all the ideas we've had so far. If you want to, you can go ahead and sort of give your opinion on each idea. I'll do mine for an example:
1: I like this idea a lot.
1-A: I think this would be suitable.
1-B: I'm not sure about this, it could get very complicated.
1-C: This is probably the best way to keep it organized.
1-D: I don't think this idea would work out, it could end up making it more difficult for the authors.
2: This could be fun, but also very difficult to organize and keep working.
3: This is a very good idea, and I think we'd all have fun with it.
As you can see by my 'votes', idea 1 (and 1-A, 1-C) and idea 3, are my favourite choices