Yes, magic means I can say 'make it so' and it is. But I see too many options and not sure which ones would make more sense. I'm picking one idea that I've never seen in a book.

So a Magivore is an animal that 'eats' magic to survive. (I'm thinking of things like Chemovore? Thermovores)

In this particular case the Magivore is like a bacteria, it gives a spell caster a 'cold' seriously affecting his/her ability to perform magic lets call it "The Jitters". It can spread like the common cold too, affecting others.

Now I'm wondering about detection, spread and sterilization of such a critter How?. It would also make magical warfare more interesting, get a Typhoid Mary or two... It would become more essential to be able to deal with it...

I've been working on this to make it a decent question but not sure if it has made it over the hump. More than willing to improve it

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    $\begingroup$ An interesting idea would be if it eventually ate the magic user. $\endgroup$
    – Jax
    Mar 27, 2015 at 13:46
  • $\begingroup$ Like from Cabin Fever----where it eventually searches and destroys his body in the process when it runs out of magic. $\endgroup$
    – Jax
    Mar 27, 2015 at 13:49
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    $\begingroup$ Too make it over the hump, I would suggest adding a question mark somewhere. $\endgroup$ Mar 27, 2015 at 13:59
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    $\begingroup$ I'm thinking that if you were to provide details on how magic works in this world, one of two things will happen: 1) you get better answers from people, or 2) you figure it out for yourself. Magic tends to be self-solving (which is why this fortnightly challenge is so hard). $\endgroup$
    – Frostfyre
    Mar 27, 2015 at 14:18
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    $\begingroup$ @Josh sounds about right, didn't know they already had one $\endgroup$
    – bowlturner
    Mar 27, 2015 at 18:43

8 Answers 8



A wizard might wake up one day and feel that his magic is weaker. Spells and incantations that normally come naturally to him seem harder to grasp, and casting them takes a toll on the user.

Depending on the level of technology in your world, this bacteria could be considered a curse, or a divine punishment. Doubtless very few of the common folk - even magic users would take a while to figure out exactly what is going on. This magical blight could not be cured by any magical means, as any attempts to get rid of it would only be devoured by the bacteria. Technically, one could 'verify' that they have the bacteria by injuring themselves and attempting to cure or heal the wound using magic.


If this is a bacteria with magical properties, as you said, it could be spread in a similar fashion to any bacteria. Contact with the infected, or with contaminated items are enough to spread the Magivore to a new host.

As for magical warfare, an infected person - even a non-magic user - could easily infiltrate an enemy kingdom or school of magic and wreak havoc.


Obviously, a simple Cure Disease spell isn't going to work here. However, your world could take a cue from our own Black Death here and adopt basic hygiene methods such as washing regularly, sterilizing foods before eating, and disposing of waste cleanly and efficiently.

Alternatively, there are several plants that produce naturally-growing antibiotics that could help get rid of infection. There's a list here with a variety of medicinal and antibacterial plants and herbs, if you'd like to take a look. I would imagine alchemists and potion-brewers would be in high demand during and after this outbreak.

  • $\begingroup$ I'm really liking this answer! $\endgroup$
    – bowlturner
    Mar 27, 2015 at 14:38
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    $\begingroup$ Or perhaps Cure Disease would work fine, though the one with the disease couldn't cast it on himself for obvious reasons. Either it wouldn't be possible due to the lack of mana, or it would be very dangerous to do so, possibly creating unwanted side-effects casting a spell without 100% mana required in order to do so. $\endgroup$
    – Neil
    Mar 27, 2015 at 16:32
  • $\begingroup$ "Technically, one could 'verify' that they have the bacteria by injuring themselves and attempting to cure or heal the wound using magic." couldn't you just use a different spell, like a flashlight spell? $\endgroup$ Jun 26, 2017 at 11:43
  • $\begingroup$ Also, couldn't there theoretically be a type of magic that is immune to the disease. $\endgroup$ Jun 26, 2017 at 11:44
  • $\begingroup$ Alternative Cure: The mage in question has to drain himself of ANY mana for like 3 days, for the bacteria to starve out (or be dealt with by the immune system since it itself desn't have mana anymore), the mage could do that by constantly casting the most minor spells whenever he can $\endgroup$
    – Hobbamok
    Jun 19, 2019 at 9:11

So your giving your characters, and the society they live in, the freedom to conjure and create, but only at the risk of attracting a magivore which will take their magical abilities away. Sort of like a "get out of jail free" card that you might only be able to use once. That elevates the choosing of which crime to commit, to a very interesting level. I'm using the word "crime" here with a little artistic license. I don't want to imply that using magic is in any way morally wrong.

Two schools of thought are obvious...

  1. There will be some who use their magic immediately, to jump ahead of the competition, hoping to create the seeds of a prosperous life and set themselves up before they loose the ability. These people are gambling on their ability survive and thrive after the magic is gone.

  2. Others will hold onto their magic to use as a last resort. These people are gambling on their ability to find prosperity without magical assistance and pessimistically, they are trying to stay prepared for the inevitable challenge that only magic can solve.

Both attitudes have merit, but since your magivores spread like a common cold, the second type of people are gambling against their likelihood of catching that cold and loosing the magic without ever getting any benefit from it.

Detecting it: Magic is out in the open, accepted by the society and free from secrecy. Contracting a Magivore infestation would probably be comparable to getting leprosy. Once your magic falters, people wouldn't want to get near you anymore. There would be isolated colonies for contaminated people and social customs would evolve to test for contamination before getting to close to a stranger. I didn't know either of the approaching men, so I gestured a rune in the air between us. The glowing lines of my magic shone in the air between us, demanding that they respond. They each gestured in kind, and the light they caste was free of flicker or fault. Confident in our mutual safety, we dropped our runes and entered the room together.

Spreading it: You've suggested that magivores are like bacteria, but I would find it more interesting if they were larger, maybe mouse size, invisible and intangible flying creatures. Their invisibility, intangibility and flight capabilities might be the very reason that they need to eat magic, to keep their defenses working. If they were flying ghost-mice, you could still have your characters and their society thinking that they are a disease. It might just happen that glass, plastic and latex can block their intangibility, so normal anti-bacterial defenses would also work against them. Until somebody caught one in its magic-starved, defenseless state, nobody would know that they were an infestation rather than a infection.

Sterilizing it: Personally, I would leave the culture impotent in their attempts to cure the "sickness". Since they fundamentally misunderstand the nature of their enemy, everything they have tried has failed. Magivore infection, like leprosy or a social disease, would be seen as a permanent, non-fatal condition, with a slight chance of remission, but no hope for a cure. This would free you to use your new creation in some very real social commentary. Any fiction you wrote about the world where these creatures live could easily be crafted into a metaphor of our world, with magic representing sex and the magivores playing all the dark roles from VD to Aids. Such metaphors are precious and rare, so you should make use of them when you find them.

  • $\begingroup$ Another great answer! $\endgroup$
    – bowlturner
    Mar 27, 2015 at 14:50

Make magic eatable - The word mana comes into mind as first. But because recently I finished Frank Herbert's Dune, I am having spice in mind: You eat it and the higher volume in your blood, the more magical abilities you have. Above certain volume of mana in your blood, you have to train your mind in order to manage normal living.

So, in other words, such bacteria would survive on natural resources of mana.

Infection: While eating mana can be pretty safe, you actually get infected if some of mana gets in your blood directly - does not go through your digestive system (which could kill the bacteria). Simple small injury in your mouth can get you infected.

Killing it off: Such bacteria should not be really deadly. Lying down for one week, not eating mana should get you well (as of common flu. I know that flu is virus, but just for your idea)

Protection: Magical rituals. Duh. In magical rituals, you do a loads of weird looking stuff involving weird fluids. So why not to wash your hands using some destillate?

Mindset Such disease would be considered as "If you play with fire you can get burned" and accepted as common backfire of doing black magic. People would die in same way as we die on having flu.

Obviously, the biggest hurdle to overcome for you is, how you actually tell in the story itself, that It was bacteria all the time. And sadly, I do not have answer for this


Generally speaking, magical fantasies have this much in common - a lot of uninhabited space and the concept of wizards being 'ascended', in touch with their higher natures or whatever.

The magivore you said eats magic to survive - then the obvious cure would be to supress one's magic by entering a trance; the magivore should simply starve to death. This also requires the wizard to enter a remote place, since on finding no food source the creature will actively seek out other sources.

As for warfare, using the magivore could be a two-edged sword. On one hand it cannot be preserved without nourishment - meaning you'll need someone infected with it close to the battlefield - where they could infect their own. On the other hand it could spawn some sort of outcast guild or brotherhood who specialize in anti-magic warfare - sort of like how poor lepers were outcasts and are still in many countries.

A third method would be to somehow seal it in vacuum spheres or something and have a mage feed magic into the sphere to keep the magivore alive. Firing said sphere into the enemy camp would cause the now-starving magivore to infect viciously.

Detection? It would be awesome if there were a stain on the eye. The wizard himself would not see it (unless mirrors are common) and it can prove to be a good twist for a particularly respected one to suddenly find himself shunned. In fact I'm sure it would prove to be a new era if many wizards went into exile to cure themselves of the magivore.


The Magivore nature must depend on the nature of its food (some kind of resource, "mana", whatever).

  1. Is destroying magic only a side-effect? Is "mana" the only kind of food they eat?
  2. What is the source of this resource? Is it being generated by humans, or is it being controlled by humans but generated by some kind of nature sources?
  3. Is this source (and mana itself) transcendental to the world? Or is it just a part of the world? (some kind of energy or a chemical)

If "mana" is being generated by humans performing magic spells, and magivores eat it completely, they are doomed to starving death. They must become parasites, weak spellcasters, but not ultimately deny spellcasting. However, one could get rid of magivores, temporary suspending their magic practices.

If the source are transcendental, so must be magivores. In this case, you could never find them without using magic. Basically, our modern world could be populated with magivores, and they are the reason we cannot use magic anymore.


Suppose a creature eats mana or magic.

What is mana?

D&D's Planescape has the possible answer that different dimensions or planes that are strongly tied to different concepts and moralities such as heaven or hell. Furthermore, it has the idea that certain creatures such as Angels or Demons are composed of the substance of the plane that they live on.

I like this idea. So in some of my settings, mana is strongly held moralities and concepts in material form, souls are made out of a form of mana and dimensions are made out of a form of mana.

Drawing upon this idea you could have a magivore that is a type of spiritual tapeworm that eats mana and the souls of infected creatures.


Souls are a form of mana and can be seen the same way magic can be seen and detected. Spells such as Detect Magic or Detect Evil could be used to detect the tapeworm infection.


These tapeworms are spread along with the transfer of mana. Mana is just strong concepts and moralities and so the tapeworms are spread through discussions and conversations on ethics. These tapeworms are also spread through the use of magic spells.


These tapeworms survive best on unaligned mana. Very good or evil souls are poisonous to these tapeworms. So, holy scripture and religious practices of all sorts would be used to ward off these tapeworms. Very powerful aligned energies such as from holy water, the fires of hell or a large group of zombies could be used to kill the tape worms as well.


Have magic as a power from another realm, one invisible and intangible. Magic users can channel that, and the magivore gets in the way. When magic is used on something or someone, the caster is linked to the target through that realm.

Detection The mage's spells don't have as much horsepower as they used to. If some of the spells are used for his own health, this can hurt or kill him.

Spread It can spread through contact, but can also spread over a distance if someone casts a spell on someone already infected. If another mage is brought in to cast a diagnostic spell, poof, he catches it too. The same for anyone trying healing spells.

Cure The victim must refrain from all magic for a few months, and no magic can be used on that victim, either. The thing is, magic is so danged useful that the mage has become really dependent on it. And if the mage has a job important to others, like being a healer or a combat mage, abstaining from magic may actually cost lives.

Edit: Maybe also have people handicapped by a complete lack of magical ability. These people, usually considered handicapped to some degree, would be immune to the magivore, and would, ironically, be the only ones who could safely take care of very powerful mages who are ill with this.


If mana is a consumable as in Nivin's stories, then any beast whose metabolism depends on magic, such as dragons, could be said to "eat" magic. It is a resource to be exploited by the living cell, like anything else, and a bacteria that figures out how to use (meaning both make-use-of and consume since once used it is spent) mana to exploit a niche and replicate a lot, will sound like the kind of thing you asked about.

Dragons only live in regions with mana to use as a kind of vitimin, but a primitive Prokaryote may pick up a trick of using mana fairly directly to replicate like mad. These can become organelles and internal symbiotes in Eukaryotes and higher life forms, and may be how dragons are able to harness mana for their limited means.

I can imagine weeds that grow near rich mana sources, and may be a way to spot magic areas. A magician concentrates mana in and around his body, so an infection would deplete his powers, mess up his application of power, and as a side effect make him sick through biological means just because they are there.


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