do the undead continue to decompose?

[Mercule]

For me, it's a matter of what kind of undead.

Tend to agree with the principle.

Skeletons and zomies continue to rot, although at a slightly arrested pace. Zombies probably decompose at about the same rate as a modern embalmed body (and probably in the same turn-to-jelly manner) but continue to stink. After a century or so, they'd be skeletons.

Ghouls wouldn't rot. I'm not sure I agree with Bendris' rather biologic explanation, but the end result would be about the same as I'd end up with.

Mummies are already preserved. I'm not sure if I'd give them a weakness to water or if I'd say they dried themselves quickly. Probably just a way to end up with a skeletal mummy.

Incorporeal undead have nothing to rot. Obviously, they are static.

Vampires are a lot like ghouls, just better looking.

I see liches rotting at a natural pace. A fresh lich could probably pass as human for a couple of days (depending on climate and available perfume). Some liches would probably not care. Others would pseudo-mummify themselves with salt or other process. Still others would grab a dagger and start cutting fillets or find a maggot bath to speed the process. Whatever provides ambulation is probably akin to what animates a skeleton and independant of the flesh. The skeleton would degrade at a normal or slightly retarded rate. By the time it becomes unusable, most liches acheive demilichdom.

 

[Sarellion]

In my world, the undead are preserved by the energies that animate them.

Or you could say that the goddess of the undead and the demi goddess of black magic want that their undead are still good looking.

 

[Bendris Noulg]

Ghouls wouldn't rot. I'm not sure I agree with Bendris' rather biologic explanation, but the end result would be about the same as I'd end up with.

...

Vampires are a lot like ghouls, just better looking.

I went the route I did with these guys to explain their "need to feed" on flesh, carrion, blood or marrow, making the (flavor) ruling that some form of internal process was at work that derived unnatural life-sustaining energy from such consumation.

Then again, I've got some unusual twists for Ghouls and Ghasts to begin with (between the BoVD and MC's Ghoul/Ghast Template), relating them closer to demonic possession than animated undead. But that's the way I am.

 

[Gez]

With the exception of vampires and incorporeal undead, yes. Some liches may use gentle repose to stay clean and fleshy, though.

Zombies end up becoming skeletons if they wait long enough. Ghouls becomes ghast, but finally decay overcome their willpower and they are reduced to the state of mere zombies.

Some special undead, like devourers or nightshades, don't decompose neither, since they are not built out of corpses.

 

[Alzrius]

There are, as written, no rules on undead decomposing, so the basic answer here is no.

Some undead do need to feed, such as ghouls, ghasts, and vampires, and bad things happen to them if they don't, but beyond that, the undead do not decompose in a manner that'd interfere with their stats (i.e., no appreciable decomposition that'd interfere with their having to function). You make a zombie now, and seal it away, and when adventurers come along a thousand years later, its still a zombie. It looks worse for wear, but its obviously still a zombie when seen, just more corroded. Any decomposition that happens is purely flavor material (and that phrase brings gruesome thoughts to mind). A ghoul, left to feed for centuries, will still remain a ghoul after all that time. A zombie will never just decompose down to becoming a skeleton. Decomposition doesn't make stat changes unless you're using a product that specifically deals with that.

A general rule of thumb is that where flesh remaining is important (such as with ghouls, and with zombies to distinguish them from skeletons), its still there, just more papery and shrivelled around the bones. For undead on whom flesh doesn't matter per se, such as mummies and liches, they can have flesh or be skeletal (and having them be skeletal and posing as mere skeletons is a great way to surprise a party).

And of course, vampires never decompose, looking human (or mostly human if you have more Buffy-esque vampires).

Incorporeal undead are beyond this entire question, since they have no physical bodies.