Okay, I am in the middle of reading The Mist by Stephen King. I watched the movie years ago. However, it was not much like the first short story, the one found in Skeleton Crew . Anyhow, I think it is a great setting.

I am going to do three chapters:

Early, day zero to about two weeks in.

Medium, about six months in.

Long, this will be about 20 years later. They can play as their children of their former characters if they want. There will be a small community and other rivals, chance for unity, etc.

Either way I will do no more than three chapters.

Looks like you've got heaps of interesting ideas for using this particular rule set. I really enjoyed the mist and think it will make a really interesting survival game.

Any reason for the not doing more than three chapters?

Wouldn't The Mist be more along the lines of EOTW: The Wrath the Gods? Tentacle monsters from another dimension? Not that you can't use this book to create any scenario imaginable regardless of content.. In fact, I'd be surprised if they didn't include something related to The Mist in the next book.