Here is the world, here is its history, the 'current year' as described in the fluff is XXXX.
Now create products for me to buy, that I can buy in any order, leaving whichever ones don't appeal on the shelf. Don't tell me where my campaign timeline goes, don't make future products unusable if my campaign has gone off on its own timeline. Which it should. The best inspiration for gaming was, It is the time of the Hero Wars, go out and make your mark!
Whyever would I want to take a world that I enjoy, and trash it? Then all those nice maps and reference material that I spent so much money on are just so much kindling. Might as well've just saved my money.
So, certainly, keep metaplot out of the Guide, which is a guide to the base, standard world as it was given to us for use in our own games.
Powered by hypermail