How Do I Kill It, And Why Does it Work: Vampires, Part 2
Hm... A lot of these answers are going to be dependent on setting. For example, if it's a fantasy setting, lots can be explained away by magic.
Anyways, I'll take stab (heh) at this...
Basic vampire physiology: Vampires cannot be killed through normal means because they regenerate rapidly - so rapidly, in fact, that regeneration is visually noticeable. Take a monster of their approximate level, triple the HP, and allow characters to kill it by doing that much damage - effectively bludgeoning the vampire into meat soup and scattering the bits. Throw in hefty in-combat regeneration as well.
Stake to the Heart: For whatever reason, vampires cannot regenerate their heart (feel free to extend this to their brains too! Potentially include their whole central nervous system?). The heart must be completely obliterated for it to be fatal. However, glancing blows can cause complications; if the heart is gouged, much of their regenerative power will go to keeping blood replenished and the heart at the proper pressure. Any implement whatsoever will work - a sufficiently spiky morningstar, for example, could suffice. Stakes are, however, cheap and easily wielded.
Burning: Cauterizes as it burns, requiring an egregious amount of effort to regenerate. Burning to death requires lighting a significant amount of the vampire on fire; the regeneration must be cancelled and exceeded in fire damage. After this, they rapidly burn to ash. Vampires are especially flammable, but must be exposed to something hotter than fire-warmed steel. Explosions will catch them alight.
Sunlight: Acts as burning, but instantaneous and affects all exposed body-parts. Magical side effect of vampirism.
Decapitation: Works as per stake by separating brain and body. Decapitated head must then have its brain caved in with blunt force to ensure a proper kill; bodies may eventually form off a decapitated head, but never vice versa (headless bodies are always non-threatening).
Wrapping it all up: Vampirism is a magical disease transmitted by blood/saliva/fluid contact (as saliva->blood in bites). It creates a desire for blood (and associated physiology; hearing+, smell+, fangs+) in the victim, and uses the blood in a magical/alchemical reaction to fuel regenerative powers. Vampires may be killed through traditional means, but requires such excessive force that the shortcuts - heart trauma, skull trauma, burning, and sunlight - are the best known.
In following comments:
What did you have there?
Cool! This is the kind of thing I'm looking for. Just to clarify though: Does this combat regeneration translate to if you cut off a finger, it grows back, etc.?
@C'nor: Tylhandrias/Ashton are both my accounts; having some issues with the blogspot commenting. I accidentally double-posted and removed the first. :)
Anyways, you could spin it both ways, but it makes vampires far more exciting (and threatening) enemies if they regenerate back to their original form over time. This would be dependent on wound type / extent, with burns being the hardest things to heal and lacerations the easiest. For example, a decapitated and cauterized head could regenerate its body in approximately a month (but the body couldn't regenerate a head!). It's important to note, though, that since the vampire would require a steady diet of blood to fuel the regeneration, they must be helped along by someone if they cannot seek blood alone - picture an evil minion in a dungeon, spoon-fooding a vampire head with blood daily, in the promise of power later. I think there's potential there. :)
Hmm. Sets things up nicely for something I was thinking about. See the next post for more on that. [Gnome NPC Gorbalek Lipadip is a servant of a vampire, which explains why he's in the dungeon.]
Also: Is it simply the there's no way for the body to get blood? If so I imagine a suitably insane character could work up a way to do and IV, even though we're working at D&D tech levels.
Certainly! An IV drip for the technically-minded (or the much lower-tech pool of blood, rinsed and replaced every two or three days) would probably be sufficient to allow the vampire to regenerate. Maybe a little gurgling stream of blood, so it doesn't clot... Whatever seems most appropriate for the setting / characters involved!
Better cloning through magic! (See the results for more on that)
Anyway, what I meant by that is that is: Since both the body and the head can regenerate, you could make both grow, chop off their heads, etc. until you have a vampire army. But, I''m not seeing this being common, as it means they have to share power.