Okay, so Nick Wright over at Lawful Indifferent has an interesting new series of posts about D&D 4th Edition. Well, maybe not so much a series of posts but more a series of punches in the face. Now to be fair I've only read through the rules and played a couple of introductory games of 4E so I'm not sure whether I'd enjoy an actual full campaign or not. However from what I know I really do have to agree with pretty much all of Nick's points.
But one of his more general comments got me thinking.
""But that doesn't jive with the fiction in 4th edition world, because
monsters range from levels 1-30, inclusively. And so do heroes. And so
you have a conundrum. Why haven't the level 26 Yuan-Ti razed all the
towns in the world yet? Why hasn't the level 19 Red Arcanian reduced
half the world to ash yet? What is stopping them? There are only three real explanations; either they don't want to, they already have, or they can't."
This is one of the core design questions with D&D/Pathfinder: why haven't the high level baddies, particularly when there are entire races of high level baddies, already taken over? This plays into campaign world design by the DM. As DM if you want to have the high level evils in your game then you really have to provide answers.
But then I went over to the Pathfinder SRD site to check out what monsters there are at higher levels, say 15+ that game. The vast majority of the creatures listed are either dragons, giants, golems, or extra-planar creatures, such as demons. It's not until you get down to around level 9 that more "normal" creatures begin to show up in significant numbers.
So most of those creatures are in other dimensions. Thus you can leave them out of the picture until the PCs are ready for them. Then either the plot takes them to another dimension or you come up with a plot device as to why they suddenly now have some sort of major access to the prime material plane. Dragons are not from other dimensions (although they could be) but the high level ones are very old and thus there should only be a couple of them.
Also, the evil high level creatures are mostly balanced out by the existence of good high level creatures. So a demon invasion could spark a counter-invasion by corresponding divine types. And for every ancient evil dragon there is an ancient good dragon.
Nick also notes that one possibility is that they don't want to. Creatures in other dimensions may be only dimly aware or totally unaware of what is happening on other planes. Plus the evil types are usually so busy plotting against each other that the effort of invading another plane could prove a fatal distraction. There would have to be something of great value there to make the diversion of resources worth the risk. Dragons, too, are probably so busy with plotting and politics within their own societies that they don't have time to waste on crappy little towns.
But then there's the idea that the high level baddies already have taken over. Obviously if they're currently in control of the entire world then a party of beginning characters doesn't stand much of a chance. Or you could have it that they did ravage the world earlier then most of them departed when there was nothing significant left to ravage. That sets up an interesting post-apocalyptic world setting, with the constant worry that the evil will return one day (like when the characters get to a high enough level).
However you could also have the baddies in control of just portions of the world. This is essentially the approach I'm taking with my new campaign world. The dragons control areas near the five poles of elemental power which the original divine guardian dragons were created to protect; but my dragons are naturally neutral due to their elemental origins so they don't just kill everyone in sight for fun. Pantheons of evil deities control several regions of the world and life there is grim. But pantheons of good deities control other regions and so there is hope.