I don't usually use vampires as main characters. They're normally supporting characters for more, and yet less, human immortals, but I've decided to flesh them out a bit. I was thinking about advanced, hands free dead man's switches for something else when it occurred to me that none of my vampires could use any of the alternatives I was looking at.

So my question is: What physical parameters could a vampire/ghoul/zombie use for a passive body monitoring dead man's switch?

Assume the creature using the switch in question is otherwise human but has:

• no pulse


• no measurable blood pressure


• a room temperature body

If it makes a difference the switch in question is designed to send a signal pulse. This can be used to trigger either an on-site (like a jacket full of Semtex) or an off-site (like a release of files, or a computer wipe) event.

Note: I've lumped vampires, ghouls, and modern zombies together because they have similar physical characteristics and the same mythological origins even though we tend to differentiate them in modern literature.

Eye-tracking glasses

Your undead have glasses that track their eye movement.

No eye movement -> truly dead

Eye movement -> normal undead

Depending on your undead they don't need to sleep so there is no reason to take them off. If your vampires need to rest during the day you could use the camera to watch their coffin or wherever they are sleeping and change it to a "detect light" mode. Once they are awake again they take on their glasses and turn the correct mode for eye tracking on again.

Measure brain activity.

Most variations of vitally impaired citizens which try to maintain at least a minimum of scientific plausibility either have an active brain or something which replaces the function of the brain. So you should be able to measure brain activity (or at least the activity of whatever replaces the brain).

You can use an Electroencephalograph for that purpose. It is a relatively cheap and compact device which gets attached to the head and measures the electromagnetic activity in it. If you want a higher reliability, make it less visible and don't shy away from intrusive methods, you could alternatively implant the detector into the skull.

You could even give them a more advanced detector which doesn't just check if the person is still alive un-dead but can detect certain brain wave patterns and thus allow the wearer to intentionally trigger the dead man's switch with their thoughts.

If your vitally impaired people don't have brain activity, then there got to be some magic power which controls them. In that case you might be able to somehow measure that magic power.

Another bio-function you could measure is their digestive system. Vampires drink blood, ghouls and zombies eat human flesh. That means they need a working digestive system. The activity of the digestive system might be measurable. This might be easier to do with those vitally impaired people who prefer solid food, because they will need active intestines in order to digest that food. The chunks of flesh moving through their guts should generate measurable movement. Curiously, I can not think of any source of zombie lore which mentions whether or not zombies defecate. Intuitively, I would say they do, because some sources say that zombies must eat to survive and a 100% effective metabolism is implausible. If your zombies consume flesh out of instinct but don't actually get nutrients from it, then their stomachs would quickly burst while eating. While a zombie walking around with an open belly oozing a sludge of stomach acid and half-digested flesh is certainly very zombie-esque*, I can not think of any zombie lore mentioning that this is a particularly common occurrence. Also, zombies shitting themselves certainly makes them even more gross**.

It might be a bit harder for those who consume their nutrients in liquid form. Maybe they have active kidneys and a working bladder?

*_{I think I got a halloween costume for this year!}
**_{Not going to incorporate that into my costume, though}

Hollywood effects

In modern films, many undead creatures die spectacularly, because it makes for good cinema, and hey, why not. Since these are your vampires/ghouls/zombies, you can make their death throes whatever you like.

But, let's say it includes bodily disintegration -- after all, the corpse has been rotting for years and is only held together by the forces of necromancy / dark science / plot convenience.

So the switch is a large, spring loaded contraption embedded in the chest cavity. Kill your vampire, and everyone crowds around to watch the swirly tornado of ash the FX crew are CGI-ing in; someone notices the tips of the probes starting to tear through the disintegrating ribs -- "What's that?", they cry, and lean closer for a better look -- BOOM.

An advantage is that unlike most terrorist style dead men's switches, false positives are unlikely: chest cavity disintegration will always be either a symptom of death, or a cause of it.

Plot-wise, once the living wise up, there are a couple of ways you have a slim chance to override the device -- shove your vampire in an iron maiden, for example.

A thin wire and/or mesh

If we assume that vampires can be killed by decapitation, a stake through their heart and by sunlight... ghouls and zombies only by decapitation or massive brain damage.

...and if we assume the character in question is cooperative and has some assistance...

...the solution is to run a thin wire loop/mesh under their skin. Start by wrapping it around their heart, or chest if you do not want to go as deep. Then run it up their neck, a few wraps around the skull, and then down again, ending at the dead man switch activator in the chest, located just under the sternum .

If the wire is cut, this activates the switch.

Vampires have a special version that is also activated if it detects light.

CAUTION: Do not use vampire version of the activator on zombies because zombies are of... "questionable physical integrity". You may choose to forgo to the heart wrap/mesh if you think your character is not particularly bothered by a stab to the heart.

Vampires, ghouls and modern zombies have different features, but they all move (if they didn't, well, all horror stories would be pretty boring, or their human protagonists even dumber than today. I mean, leaving the group to enter a dark room alone is already a bad idea. Seeing a still vampire and going into its hug is really, really bad idea.).

Just use an accelerometer to detect movements (a step counter might be enough) and let it act as dead man switch.