What would cause magic spells to be irreversible?

Question

For context of the idea I have in mind, the setting is a modern world, but with magic.

All sorts of things are possible with magic, but most notably spells that would change or transform an existing thing are permanent. Always. Any effect applied to an object or living being can never be undone by magic. A rabbit plushie materialized and pulled from a hat (magic cannot create living things) can never be vanished by another spell, while vanishing a human being or turning them into a marble statue is tantamount to murder.

Note that this doesn't cause spells to only be usable once or render non-magical reversal impossible. You can still hurl as many fireballs as you want or transform an entire herd of cows into vicious lions (given the magic stamina or whatever). A bicycle assembled with magic would be immune to sabotage spells, but would still break from crashing into trees. Counter-spells don't exist, but that doesn't stop you from summoning a gust to blow away an incoming fireball.

What is it that makes spells irreversible?

Answer 1

The nature of magical entropy is still under intensive study but it is clear that a spell causes "magical entropy" and just as you can not unscramble an egg, or unburn a piece of wood, you can not reverse a spell. Magic expended can not be reverse, and unlike normal entropy, that's not just on a universal basis; localized reversal is not possible.

This is widely regarded as deeply counterintuitive, especially given that many spells create localized decreases in more normal entropy. Nevertheless, that is the situation.

Answer 2

The item swaps places with the same item from a parallel nonmagic universe.

All possible realities coexist. In most, magic is not possible. When you use magic on an item to change it, the item switches places with an item from a similar parallel universe. If you magically turn your dog blonde you will probably get your dog from a parallel universe where you had earlier nonmagically turned your dog blonde with lemon juice. Your nonblonde dog goes there. The lions that you turn the cows into come from a place where they were lions and the cows go someplace else - possibly where the lions were. When you turn me into a statue, that statue is from an enlightened dimension where there are statues of me and hopefully I am sent to that same place because I bet I eat for free.

These items from nonmagical realities are (usually) nonmagical and so no more magic on them. The statue of me stays, although people might adorn it with manly nonmagical hats. Every now and then, by chance, an item swapped comes from a parallel universe that is not so similar to ours. The lions might be reddish, or with stripes. The statue you "turn me into" may have physical attributes that the fleshly version of me did not have, and may be dressed in a way that would have got me arrested, back when I was present in the flesh. Or maybe the thing that comes into our world is from a dimension that does have magic and so magic might still work on that thing, one more time. It might not work in the way people are used to, though.

Answer 3

Simple answer? It's magic.

OK, but seriously...

The natural world, and all non-magical objects within it, exist at an uncharged base state. Magic taps an energy source and performs some alteration on the target, but at the same time it produces a strong magical charge in that target. Since like charges repel any attempt to perform further magic on an object that is already magically charged will fail.

Depending on your story requirements you could have this charge dissipate over time as the object's new state becomes the new normal, allowing a transformed statue to be transformed again once the charge has grounded out.

The biggest flaw I can see here though - and forgive me if this is a frame challenge - is that a 'charged' object becomes effectively immune to magic. I'm going to go out and get some mage to enchant me with, I don't know, a cleaning aura. Boom, I'm immune to magical attacks. Physically conjured objects will still work on me, but direct magical interactions are a no. Similarly I can get my gear minimally enchanted and be immune to direct magic without having to worry about getting myself permanently cut off from magic.

Instead of letting trivial magics ruin the fun for everyone perhaps a spell's power level is the determinant for what future magics can affect something. If I get a trivial enchantment to get rid of acne that's not going to have enough of a charge to ward off an elemental attack. An act of pure creation on the other hand results in an object that is almost completely composed of magical charge, so anything less than the ultimate power level will be ineffective against it. So your plushie is safe, I'm probably safe from magically-induced acne... but a strong enough spell could still affect me.

Of course this charge might only count for certain types of magic - transmutation, conjuration, enchantment, etc. Elemental magics probably act on the element, not the target. A fireball spell produces actual fire which acts like fire normally does, so a conjured or altered target is still going to burn. Other schools of magic might produce effects that are transitory and leave no lasting charge. Evocation, abjuration, illusion, divination... lots of possibilities for magic that still works.

Answer 4

Magic is granted by the Gods

or something else with personality.

They consider magic a great privilege for us mortals, and thus become really offended if you try to undo it. They don't care if it's a different person trying to undo the magic, and they don't care why the magic was done. They love magic for its own sake, and we mortals should be grateful to have access to it, and for us to want to undo it is not only baffling, but reprehensible. They not only refuse to allow the undoing, but may punish the person trying to undo it.

For example, maybe every spell is the equivalent of a work of art and that's all they care about. To undo a spell is like trying to paint over the ceiling of the Sistine Chapel. They care as much for individual mortal lives as we do for the lives of individual blades of grass, and so the fact that undoing a spell could save a life is meaningless to them.

Answer 5

A common trope related to magic is that it is kinda like programming. This is seen in Dr. Strange's movie, for example, as explained by his mentor:

The language of the mystic arts is as old as civilization. The sorcerers of antiquity called the use of this language "spells". But if that word offends your modern sensibilities, you can call it "program". The source code that shapes reality.

If that is true, then the irreversibility of spells is in the specifications of the operating system.

Answer 6

Words uttered in a magic language always become true.

It's been a while since I've read it so I might be getting the details a bit off, but this sounds similar to how the book series Eragon handled magic. There was a magical language and anything you said in it must become true. If you said "this rock will move," it moves. If you said "this man will die now," he dies. If those things don't happen then your statement was false, so they must happen to keep the statement true, right? This is the power of the magic "always true" language.

The way they balanced this magic system was that any magic you used consumed your energy. If you utter a spell that takes more energy than you have, you're sapped clean and instantly die.

This magic system was more or less irreversible too; there was a part where the main character

attempted to bless a newborn by trying to say "you will be guarded against evil," but actually said "you will be a guard against evil." That girl grew up to be a suffering psychic burdened with seeing every way things could go wrong, and the main character could not undo this accidental curse.

Answer 7

Magic cannot occupy the same space.

If you cast a spell, that spell remains "on" to create the item you want (or the particles its composed off). A fireball's energy will not be destroyed and just spread out. Or a bicycle created by a spell could be torn to pieces, but the individual pieces would still "occupy" that space for magical energy.

Magical energy can pass through other magical energy if you want (or you could do fun stuff with the consequences of it not being able to pass through) but it cannot materialize its effects on the real world in a place where other magical energy exists.

Answer 8

All spells end in "Amen"

Consider the scene from Maleficent where her curse included the phrase "This curse will last till the end of time! No power on Earth can change it!" By ending her curse thusly, she bound her curse making it such that no one, not even herself could undo it. But, what if your magic language made saying the same thing MUCH easier?

This is where "Amen" comes in. This is a single word that people routinely and habitually put at the end of their prayers which means "so be it". Leaving Amen out of a prayer (or spell in your case) is like leaving it unfinished. But by ending a spell in Amen, you are not just finishing your spell, but you are binding its permanence. In your magic language, just saying "so be it" is the same as saying "so be it without exception".

So in your world, maybe a wizard could choose to end a spell in "... until I say otherwise, Amen" or "... until tomorrow, Amen" and such a spell could be broken when the exception is meet. But like SQL queries missing a WHERE clause, it would be quite common to accidentally cast a spell with a greater scope than intended because that is the default of how the magic language works. And just like many database Admins have caused irreparable damage for want of an exception, so to would your wizards, especially the novice ones, be prone to casting irreparable spells.

Answer 9

The world is an illusion, a dream. Magic is the only truth.

While we can't perceive it, our world is very unstable, uncertain. We don't really know what it is, maybe the dream of a god ? A floating idea ?

What we did found, however, is that there's a way to take advantage of that uncertainty. Using magic, we can order and change the world around us (which is truly amazing). The consequence of that, though, is that it makes the world unchangeable in the process. What used to be undefined becomes written in stone, for ever.

What was maybe a stone becomes a true chair. A true chair will still break, mold... it's a normal chair, it just can't be rewritten anymore.

Answer 10

Make the spell "radar"-like. It cannot be reversed because said from the end to the beginning it would sound identical. Think: "kayak".

Maybe not exactly the answer you expect, but that is the first thing that came to my mind when I read the question... :)

Answer 11

Magic comes from geometry

---

To use magic, a person or creature must be able to perceive extra-dimensional geometries that compose reality. A skill that intrinsically forms in the minds of the gifted as instinctive perception of patterns, as if the next biological step to the comprehension of and evolution of mathematics; and/or is studied extensively, allowing ever-growing complex thought mechanisms to mutate not matter nor ether, but reality as bound to time and space, geometrically.

Everlasting

---

The resulting effects of magic applied leaves behind a disfigured shape to the eyes of mages, a shape crafted from an individual's conjecture of active perspective versus reality perceived in comune, or as they call it: A mage's trail of "quiddity" (example).

Such reality distortions can be undone or changed by the use of magic no more, for they cannot be measured nor understood anymore, not even by the keenest and gifted, although techniques have been employed and are being developed since the first of magus to study those trails and help society prevail amidst magical chaos.

Identifiable Source

---

Quiddities can be analysed for similarities (since such a thing is fruit of the exercise of mind, and each mind is individual) to eventually identify a common caster between multiple spells, quite like how modern forensics works.

Answer 12

It just… is permanent. You can't really undo an origami swan, either: once folded, the paper can never be un-creased. (Well, you can iron it. Maybe there actually is a method of undoing magic, but it's difficult and impractical and risks destroying reality.) Doing magic leaves a fold in the substance of things and it can't be un-creased.

Answer 13

As other answers have already implied, Entropy. If you cast a spell to turn a person into a plank of wood then anything that makes a person a person is lost. If you attempt to turn that plank of wood back into the original person then you must add all that was lost. How can a wizard/mage know what was lost? It no longer exists so you cannot reverse it.

Answer 14

Im a powerful wizard. Yet, I cannot succintly perfectly describe the personality and features of my even my own dog companion.

You must accurately describe the actions of your spell, a person would take a millenia to describe. So if I cast a spell to change you into a "brown dog", it would take me a lifetime to cast a spell to put you back exactly as you were. (If I had the knowledge to describe that state!)

Answer 15

You can destroy a plushie rabbit or turn it into a gin&tonic - no limits. But if this plushie rabbit is pulled from a hat, you can't do anything anymore. Not even levitate it.

Sounds like the magic just sticks on something like an invisible teflon coat.

It may give you an interesting plot development if someone works out how to shed a teflon coat.

Answer 16

Magic is magic. What more explanation do you need?

As the worldbuilder, you make up the rules of magic. You are under no obligation to provide an explanation. If you try to explain every single thing magic does in your universe in an internally consistent matter, then you no longer deal with magic, you deal with a new branch of physics.

But if you really want a physically plausible explanation for it, then you could say that what magic does is to not just turn matter into different matter, but actually transmutes the subatomic particles that matter is made of into a different kind of particles which usually don't occur naturally. Those new particles behave in the exact same way as the regular ones, with just one exception: Magic no longer works on them. So any matter which was affected by magic once can never again be affected by magic, but is otherwise indistinguishable from regular matter.

Answer 17

Explain it by analogy to a thermosetting polymer

A thermosetting polymer/plastic can be melted or dissolved, but only once. Once it has cured, it holds its shape and can't be melted again. It's just part of its chemical structure; it has bonded together more strongly than before.

So from the point of view of your magic, all matter is like the polymer (pre-melting) and the transformation spell is a catalyst that liquifies it, shapes it into a new shape and lets it cure. But once it has cured, something metaphysical about the form of the object is "set" forever, and can't be reshaped.

Answer 18

Do what was done in "Gargoyles". Human magic is permeant there... however it's also difficult to pull off flawless magic. To get around this spells are usually written with their own escape clauses which would end the spell (and in an ancient language, Latin being the most common, though Hebrew was used in one episode featuring golems).

As long as you offer a condition which the spell can break, the spell is alot easier... the conditions can be difficult to pull off, but mundane attempts to meet the conditions meet the conditions. For example, the spell at the center of how the titular heroes get from 994 AD to 1994 curses the Gargoyles to remain in their stone sleep (a natural body function of their race) until "The castle rises above the clouds." For 1,000 years, they were stone, even at night... until a wealthy industrialist bought the Scottish Castle, and had the entire structure moved brick by brick to the top of his Manhattan sky scrapper to function as his personal penthouse. Since the building crosses the cloud ceiling on a stormy night, the spell is broken and the Gargoyles awake. In another example, the spell in question actually has two different "break clauses". A villain casts a spell on New York City that will cause all humans to turn to stone at night, though the first requirement to trigger the spell is that it will only affect "All who see this, All who hear this" through a television broadcast on repeated loop. This becomes important as the Gargoyles have a blind human ally, who "heard the spell" but couldn't see the program (One of the Gargoyles points out that this is true of all magic, but the Latin words do actually say this making it a requirement for the effect to occur). Another recurring background character claimed she wasn't turned to stone that night because she doesn't watch television, thinking it's all trash anyway. The second clause comes into play is that the spell will last until "the skies burn" which is easy enough for the heroes to pull off... they release a flammable gas into the upper atmosphere and detonate it, breaking the spell (the drama of the scene was that the villain discovered the plot and programed the detonators to go off prematurely... killing her foes... the team that returned first had to get the password to set the detonators back to the agreed time from the villain).

It is important to note that while there is an actual counterspell for all magic in the magical system, the page containing the counter-spell from the book that is the source of all the show's human magic was destroyed, thus it's unavailable for the heroes.

Perhaps the magic is locked because the spell contains the "counterspell" conditions, which the caster can set at his or her own discretion. Thus the person turning someone to a statue will set the terms when they return to being a person... you can't counter spell it without knowing the terms (If I turn your romantic interest to stone, she's not dead because I did put in a counter-spell clause as part of the requirement to cast... but I'm not telling you what conditions need to be met. Not only does it effectively "kill" her as far as we're concerned, it protects me from you exacting deathly revenge. You need me to know how to release her from the spell. Kill me, and that's not going to happen.). Think of it as a password protecting the spell.