Going from Gimmick to Campaign

[Exileman]

I have the bare bones of a campaign Idea that I would really appreciate some fleshing out of for 3.5 D&D.  I was reminded of the Locate city fell drain bomb and realized that would be an excellant campaign hook.  So, in setting (no specific campaign setting, just rolling with it for now) 4-5 generations back, a 17th level spellcaster created a Locate city fell drain bomb magic item. (For those not familiar, you use locate city which has a range of 10 miles/level and use metamagic to make it so the entire area takes 1 negative level)  He then uses it until he dies of level drain.  This creates a large area tainted by necromatic energy and lots and lots of wights and other undead.  The big Quest is to get the magic item.  I really wanna go from this one really really broad stroke, to a few les broad but still decently broad strokes and maybe a few minor details that would really add some meat to this concept (or tofu if you're vegetarian, I don't judge).

A few suggestions I've received are to make encounter tables, which makes sense.  Heroes of horror and tainted landscape rules make alot of sense.  Creatures that have been altered by the draining, but aren't undead, so that the heroes get a bit of a loop thrown at them.  I've had the idea that some divine casters are living just inside the area attempting to "purify" the area. 

I have also posted alot of this on Giant in the Playground, for reference.

Thank you guys for whatever you come up with.

[sirpercival]

Well, what you have is premise, but not plot.  So, think about the ramifications of this.  Who knows about the item?  Who benefited from the destruction, and what did they do once it happened?

[Unbeliever]

I kind of like pseudo-apocalyptic games.  If you want to go that angle, or you want a bit of a survival-horror feel, you can make the characters live through the LC bomb.  Maybe they've just come back from an adventure, and have some item of Death Ward on them, or a lingering enchantment or something.  Or, are sufficiently high level just to survive it.  Then they have an immediate impetus to figure out what the hell is going on and maybe reverse it since their home/home base has become pretty unpleasant and unlivable. 

[SneeR]

Living spells are great for this kind of thing! The necromantic energy tainted and mixed with any powerful spells being cast within it to create living spells!