Worldbuilding: Raise the Dead

If you have undead in your world, how do they work?

Don’t count undead out of an SF setting. I ran across a good short story where vampirism was caused by a symbiotic bacteria reanimating someone nearly dead; hence the vulnerability to garlic (antibiotic) and sunlight (UV disinfectant). I’m sure nanotechnology and future genetic engineering will come up with even more options. And can an AI based on a person qualify as a ghost, or at least a repeating phantasm?

But mostly I’m going with fantasy here. So, first off, where do your undead get their energy? Sure, many of them attack and drain the living of strength and blood; wights, wraiths, vampires, and ghosts have all been known to feed on human life energy, not just flesh. But that hardly seems an equal energy exchange to fuel predators that may fly, shapeshift, turn ethereal, throw telekinetic fits, and exhibit superhuman strength. Some of that energy has to come from somewhere else.

Old-style D&D came up with a neat solution, establishing Positive and Negative Energy planes “overlaid” on the Prime Material Plane of the “ordinary world”. Healing energy, as seen in creatures like unicorns and eladrin, was drawn from the positive plane. Necromantic energy, sustaining undead and fueling various spells of harm, came from the negative plane. There were never any real in-depth explanations for how a specific undead ended up linked to a whole ‘nother plane, but at least you could point at “zombies keep moving until destroyed because they keep pulling in more negative energy”.

Cultivation systems as shown in recent wuxia and xianxia settings have similar elements. There’s righteous cultivation, people working with natural forces to accomplish superhuman feats, and then there’s resentful energy, created by vice, disorder, resentments, and living beings dying with all of the above. Murder creates ghosts; ghosts can soak up enough energy to manifest, and really ticked off ghosts can raise their bodies as fierce corpses. AKA fast smart zombie time, and run like hell. You can see the inspiration for Kabane. Or maybe it’s the other way around, given traditional Chinese undead corpses hop.

(Yes, I’ve been watching the Grandmaster of Demonic Cultivation animation on YouTube. It’s a great example of Beware the Nice Ones. Not to mention some excellent foreshadowing when Wei Wuxian uses resentful energy the first time almost by accident, protecting himself and a rabbit from being torn to shreds. After all, if a genuine Nice Guy is willing to do that for a rabbit, what happens when someone threatens people?

…Cue the chaos of the series in a nutshell.)

So once you’ve decided what energy fuels your undead, then you need to decide if it’s something humans can mess with. In traditional fantasy, the answer is generally yes, dark necromancers are classic villains. Also traditionally, it’s not a good idea. Not for any human that wants to stay sane, healthy, and on this side of the grave.

So is it possible to have a good guy necromancer? Do they all eventually slip into evil? Is there any way to mitigate that? Is it an unstoppable spiritual corruption, or is it more like working with radioactivity: dangerous, but if you know what precautions to take, you’re reasonably safe.

Whether or not someone can create undead or only control existing creatures is another consideration. Vampire and zombie bites are fairly well known in modern works as spreading undeath, but in folklore attacks by any unloving creature might drag an unlucky victim into undeath as well. And then of course there’s spontaneous generation: murders, suicides, and evil people dying all tend to leave a restless something behind.

If all you want in your world is the occasional murdered ghost stalking the battlements to pour out a tale of woe in Denmark, maybe you don’t need explanations for “how”. But if undead are frequent enough that “vampire hunter” is a legit occupation, it’s time to figure out not just how, but who, what, why, and where!