The underlying magical forces at work in the universe, or at least in this section of it, are, quite literally, alive. And more often than not, they are completely amoral. At best they are whimsical, in a way that would normally be completely harmless. They just want to play. (Speaking of which, the dire wolf over there also just wants to play. We advise you go play with the dire wolf. It's safer, trust us.)
But if you are not so lucky, you may trip over a sentient magical force that wants something. Maybe it's hungry, and wants to eat your soul. Or maybe it's lonely and tries to get you to stay a while. You know, just for a few eternities. Not to be confused with cases where someone either gets lost in the underlying magical fabric of the universe all on their own, or decide they like it there so much there that they're staying.
Casting a spell with this kind of magic is often extremely dangerous. You either have to convince magic to do what you want it to, subdue it in a battle of wills, or accept that you are basically tilting the metaphorical pinball machine of reality. Another danger of using wild magic to cast spells, generally more prominent when using methods 1 or 3, is a Heroic RRoD. New users may also Go Mad from the Revelation.
Particularly powerful Wild Magic may take the form of a Background Magic Field that renders reality unstable. Or, in other words, reality is a Reality Warper. It will frequently mistake your mind for a set of inspirational prompts. Think happy thoughts. Think happy thoughts very, very, hard.
Contrast with Ritual Magic, where the procedures are orderly and strict. Compare and contrast Magic Realism, which on the one hand treats magic as having a life of its own but also makes it subtler and/or weaker. May be a Random Effect Spell in video games.
- Most magic in Slayers is either rule magic or theurgic, but Lina's Dangerous Forbidden Technique is wild magic. The Giga Slave is a version of a powerful theurgic spell, modified to call upon Chaos itself. As Chaos is both powerful beyond everything, and more than a little chaotic, there's the minor problem that a miscast Giga Slave could destroy the entire world. Or not. The Lord of Nightmares is a very capricious being, and her mind always follows her power, so it really all depends on how she's feeling.
- In Hunter × Hunter, Kite's Crazy Slots ability takes the form of a jester-like being that will spin a wheel on its tongue and turn into whatever supernatural weapon corresponds with that number. Crazy Slots has a mind of its own and honestly doesn't care much about Kite's well-being. Crazy Slots is notable for being a case of this trope in a series otherwise full of Magic A Is Magic A, though Kite designed this ability like this on purpose as he reasoned this lack of control means the ability must be stronger (and he's right).
- The drops in the anime adaptation of Puzzle & Dragons X act as a Background Magic Field that tends to act strangely whenever a monster is about to appear and start rampaging, though there are also benign examples such as giving a village elder who passed away a sendoff by putting on a light show during his funeral.
- Reed Richards of the Fantastic Four doesn't like magic for this reason. Doom once trapped Reed by locking him up in a room full of magic tomes that could only be opened with simple apprentice level magic. Reed followed the instructions in the books exactly, and the magic backfired because it turns out magic doesn't like people taking an academic approach to it.
- Legends of Baldur's Gate: Delina is a wild mage (as per use in the Forgotten Realms source material), so her magic can have unintended effects. The fact that a spell she was aiming at a gargoyle ended up reviving the statue-ised Minsc instead is one example. So is the fact that Deniak gets turned into a dragon when he was probably just expecting dragon-ish power.
- Loki in Loki: Agent of Asgard claimed that magic runs on story and so it has a will of its own. That series leaned on the fourth wall very hard by the way.
- Child of the Storm occasionally hints that the Background Magic Field (magic being the fifth fundamental force of the universe, and the more of it there is, the more it can affect the other four) is just a little bit alive. This doesn't have much effect, most of the time, but it does lead to the growth of Genius Loci and is the reason why Black Magic twists the user so much - magic doesn't like being twisted like that, and it will twist back.
- In The Witch of the Everfree, the Everfree Forest has a haze of magic which scrambles incoming scrying spells, making it an ideal hiding place. However, it also makes it somewhat more difficult to cast spells while inside it, which prevents Sunset from teleporting out of danger as quickly as she would otherwise be able to.
- In the My Little Pony: Equestria Girls series, before they receive the magical geodes in Legend of Everfree, the Rainbooms have little control over the magical remnant they received from the Element of Magic in the first movie, and the effects tend to be random. At first they "pony up" when playing music in Rainbow Rocks, but an effort to invoke directly The Power of Friendship falls flat. In Friendship Games the magic manifests when they expresses their respective Element, but they take a while to realize it. Sunset Shimmer's attempt to analyze the magic scientifically in the short "The Science of Magic" results in a power outage, a deluge of apples, a rush of static-charged balloons, or a rainbow-colored splash of goo... and very little progress in comprehension.
- In The Gamers: Dorkness Rising one of the gamers plays a Wild Mage who in their first battle tries to cast a lightning bolt, but due to a random effect is delayed until the battle is over and it hits the just resurrected bard. Oddly it never happens when he/she is frying NPCs for lulz.
- In The Magic Thief, "magics" are quite literally alive, to the point of being able to speak (in certain cases) and have wants. Most magics inhabit cities, providing a general magical aura, and the central conflict of the trilogy is how Wellmet's magic is stretched too thin and is draining away trying to provide for everyone, while the magic of a neighboring city was forced out when the city was abandoned and is so desperately lonely that it's begun attacking the Wellmet magic in hopes of displacing it and taking over. Magics in general seem to enjoy being used and providing for humans, and display signs of stress when they're unable to latch onto a city or other hub of human life.
- Enemy Glory: very active in the North Country, where reality seems to be on a constant quest to turn into the most grandiose metaphor for itself that it can come up with.
- The Last Unicorn: Schmendrick's quest is to learn to use his magic. He can't make it do a single thing, but he can let it do what it wants ... which has some surprising results. Played particularly and expressly straight when Schmendrick transforms the unicorn into a human woman to protect her from the Red Bull:
Schmendrick: "The Red Bull came for a unicorn, so she had to become something else. The magic chose the shape, not I. I am a bearer, I am a dwelling, I am a messenger..."
Molly Grue: "You are an idiot! Do you hear me? You've lost her! You've trapped her in a human body! She'll go mad!"
- Forest Kingdom: oh boy. Not only is it alive. It wants the world as its playground. The first book is about trying to stop it. The second culminates in going into the world where the embodiments of magic live and then going on a killing spree
- Greenwitch, the third book in Susan Cooper's The Dark Is Rising series. The Greenwitch is part of the Wild Magic, a force apart from (but equally as powerful as) the Light and the Dark. It's possible for others to control it, but attempting to do so is extremely dangerous.
- Discworld - in general, but especially in areas which suffered a direct strike in the Mage Wars, such as that around the Wyrmberg. Generally, the higher the amount of magic in an area, the more likely it has a personality of sorts ... and probably not an especially nice one.
- All magic in The Death Gate Cycle draws from the Wave of Possibilities, or Omniwave, which is also the force responsible for maintaining the universal balance. Normally the Wave affects individual spells very little, except to correct small flaws in them so they work, but in order to maintain balance it can cause the most powerful spells to have... interesting (and opposite) side effects. For example, any time someone is raised from the dead by necromancy, somewhere else another person will die untimely.
- Harry Potter: Accidental magic works like this. While magical schools teach spell based magic, wizarding children can tap into their own uncontrolled emotions for Reality Warper effects. This wild magic is chaotic, nearly uncontrollable and seemingly much more powerful than spell based witchcraft.
- Daine from the The Immortals uses Wild Magic, which could also be called 'animal magic' because it lets her shapeshift and talk with animals. It doesn't quite fit the above description, but it's explained as a genetic ability from her God of Hunters father and overusing it can cause regression to a primitive state of mind, at least until Numair teachers her how to control it. It's specifically called "wild" magic in the books because there is only so much control she can exercise over it.
- Circle of Magic gives us academic magic and ambient magic, ambient magic being a little more like wild magic. Academic magic is more Ritual, but ambient magic taps into the magic of the world itself and manifests itself in activities, such as cooking, weaving, gardening, sheer nothingness, and the weather. For particularly powerful mages, this can turn into Blessed with Suck.
- The Dresden Files has Demonreach, a sentient island somewhere in Lake Michigan that you can only arrive at if you mean to and which actively opposes people who try to settle on it.
- Hell, most magic. In the Dresdenverse, magic (alongside physics) is the fundamental building block that the universe is built upon. Sure, humans and various supernatural entities can draw upon magic (including using Ley Lines), and channel it to their will, but it's still wild.
- Tales of the Five Hundred Kingdoms has the Tradition, which pushes people who are susceptible to it into the paths of traditional fairy tales — the heroine of the first book is a Cinderella whose destined prince is still a child. If the magic of the Tradition can't be channeled into a tale, it simply accumulates around the person until someone decides to take it... or until the circumstances are changed until they no longer fit the story.
- In The Chronicles of Thomas Covenant, Wild Magic (channelled through white gold) is the only force powerful enough to destroy the Arch of Time. Naturally, Lord Foul spends the first two trilogies trying to get his hands on Covenant's white gold ring.
- The Old Kingdom series uses both this and Ritual Magic, though the latter is used much more often than the former, due to Free magic being extremely dangerous, as described in this trope. This actually ties into the main plot; originally, Charter magic didn't exist, but seven of the nine great spirits who created the world sought to create something more organized, and bound Free magic using the Charter. This was then used to organize and create the known world.
- Rather obviously foreshadowed in A Sudden Wild Magic. Zillah, a mage with little to no self confidence, has been constantly referred to the Arth mages of what amazing power she has, and also fittingly has no control of it. It comes to show when she manages to teleport Marcus, Josh, Philo, and herself out of Arth and into Petarchy.
- In Laura Anne Gilman's Retriever series the use of "current" borders between Force Magic and Wild Magic. Over use of it runs the risk of "wizzing out" which results in a mage that is both extremely powerful and completely insane.
- The Bas-Lag Cycle has this in the form of the Torque, which is something like a cross between this trope and The Virus. While some of the more layman characters believe it works like any of the setting's many other forms of Functional Magic, nothing could be further from the truth, and in reality, every previous attempt to harness or control the Torque led to some form of Body Horror on a massive scale.
- A fundamental part of the world of The Obsidian Trilogy. Wild Magic is essentially the consciousness of all life in the world, and works to ensure as much life survives as possible. Using Wild Magic is essentially a series of bargains; whenever it does something for you, you have to do something for it in return; what that something is isn't revealed until you cast the spell, and is rarely if ever the same twice. For instance, a spell to heal a minor injury may cost "Plant twelve acorns" one day, and "Travel in this direction until you find something to help, then help it" the next. The costs are extremely variable, but are always, always fair. At one point, Idalia Tavadon casts a spell to stop a huge, long-lasting drought which has turned a rainforest into a tinderbox; this spell carries the cost of "you must die". The time of death isn't specified, however; all the caster knows is that Wild Magic will inform them when the time comes. The next spell they cast, and any subsequent spell up until their now-inevitable death, ends up being free, or more precisely "This spell has already been paid for", due to the immense worth in dying to permanently prevent demons from ever invading the world.
- In Mogworld, magic is said to have a will of its own, and gets upset if a spell is finished by another person if the original caster is incapacitated in some way. It really doesn't like being used by corpses (i.e., the caster is killed midway through, and someone aims their severed forearm at their enemy and finishes the spell).
- In The Ascendant Kingdoms Saga, it's called visithara by mages, as opposed to human-controlled hasithara. Without the anchors of the Lords of the Blood and their manors, hasithara is entirely replaced by uncontrollable visithara, which causes magic storms that do tremendous and frequently bizarre damage (such as causing a man to disappear into an inch-deep puddle and exploding livestock) and summon monsters from other worlds. Even a partial restoration of hasithara isn't sufficient: though magic storms decrease, what spells can be cast become prone to Magic Misfire.
- In The Moon of Gomrath, the human protaganists inadvertently return the imprisoned Old Magic to the world by lighting a bonfire on a sacred mountain on the right night of the year, the Eve of Gomrath. The wizard Cadellin, Guardian of the High Magic, is not pleased and points out it took a lot of effort to imprison the damn stuff in the first place. Apparently the ordered and somewhat anally retentive High Magic is man's stuff (wizards) whilst the Old Wild Magic is that of women (The Lady in the Lake, the opposed Morrigan - and Susan, the human girl who lit the bonfire.)
- Journey to Chaos: Chaos magic is basically energy from Lady Chaos, who, as can be expected, has Blue-and-Orange Morality. Elven lore says that it deliberately backfired on Dengel Tymh to teach him an object lesson in humility. It is impossible for any mage to successfully control without becoming chaos themselves.
- In The War Gods: Magic is a raw background field of energy which can be tapped and manipulated. Traditional Wand Wizards use tools such as wands to bend magic in anyway they wish. In the west, they've mostly died out and been replaced by mages or Magi. Magi instead have specific gifts able to use the magic in a specific way. But very rarely a Wild Wizard is born, with the ability to direct the raw magic without tools. Only a Handful have ever lived, and tend to be founders of an Imperial Dynasty.
- This is effectively what the "solar wind" in Cirque du Soleil's Widget Series Solstrom is. The sun creatures who wield it are affable and playful Trickster figures, but they can't fully control its effects. When it touches a person or environment, it can have positive effects — granting magical abilities, bringing lovers together, and generally acting as a Blithe Spirit. But it can also cause heaps of trouble; in "Howling Wind", an episode heavy on Black Comedy, it turns a rundown hotel into a Hell Hotel / Haunted Castle hybrid and several of the people within it into eccentrics and even monsters. By the end, two characters are dead, two are undead, and one is a Wolf Man — and the magic causes that last one to vanish to parts unknown in The Stinger.
- The Hollow from Charmed (1998). A sentient magical force, its purpose seems to be to devour and absorb magic into itself. Powerful and difficult to control, it cannot be destroyed, merely contained and watched over by representatives of both good and evil.
- The Warp in Warhammer 40,000: Some people can harness it, but it's very dangerous for them and others. This is known as "Perils of the Warp" in game terms, and can range from manifesting patches of frost or dropping an especially fragrant fart to tearing a hole in reality, with or without an attendant Daemon or other warp horror or being possessed. This can result in any Psyker who rolls snake-eyes being shot "For Your Own Good."
- Dungeons & Dragons doesn't use this; it uses this trope's name for Entropy and Chaos Magic, but it's not otherwise this trope.
- Mage: The Awakening: The Sourcebook Night Horrors: The Unbidden discusses how the magic that the Awakened use can go wild, especially when it is able to accumulate in one place (as a result of repeated spells or activity of supernatural beings, or for entirely unknowable reasons). It also talks about how such magic can spread, and the severe effects it can have.
- GURPS Fantasy II. The strange effects on magic cast in the Madlands.
- The Nightbane Supplement Through the Glass Darkly included rules for spells that had come alive and gained sentience. Later on this lead to aclass of Magic Users who deliberately did this everytime they caste a spell called the Spell Breather.
- In Ironclaw necromancy draws upon the power of the restless dead, if someone rolls three sixes for any roll involved with black magic (casting, resisting, countering...) the spirits do other, horrific things. The Book of Mysteries supplement introduces Druid and Lutarist magic, which has some spells that carry a similar risk.
- In Castle Falkenstein, wild magic is what happens if you draw a Joker while gathering energy for a spell. The spell goes off immediately, with unpredictable effects — determined by the gamemaster, which practically guarantees it will be ... entertaining.
- Invisible Sun has the Order of Weavers, magic-users who shun formal rituals and instead take general types of magic and connect them together to get an effect. They may not get exactly what they want, but experienced Weavers can at least coax a good result out of things.
- Pathfinder: Magic normally generates somewhere beyond reality, and is called and shaped by spellcasters to power their spells. Primal magic, also called wild magic, is what happens when magic enters the world without any directing force. The result is compared to thunderstorms, with potential constantly accreting before discharging dramatically. Potential effects include rains of random objects, pits spontaneously opening in the ground, swarms of centipedes appearing out of nowhere and attacking spellecasters, surges of positive, negative and elemental energy, teleportation storms that cause people to randomly switch places, and potentially a lot more besides. Primal magic normally only occurs in areas subjected to extensive magical devastation, although it's also very common in chaos-aligned Outer Planes.
- In Dragon Age, magic draws its power from an Eldritch Location known as the Fade, where the minds of humans and elves travel to in their dreams. The use of magic is dangerous, since the Fade is also home to demons and abominations that are attracted to magic users, which can lead to demonic possession, leading to distrust of mages by others, particularly Templars. Blood Magic is especially feared by many since its use makes it easier for demons to take control of the user, in addition to being far more powerful than other schools of magic.
- In Baldur's Gate, Wild Mages are introduced in Throne of Bhaal, it being a game set in the Forgotten Realms Dungeons & Dragons setting. The Updated Re-release makes it possible to play as one from the first game in the trilogy and introduces Neera, a Wild Mage follower, as a new character. They have mostly the same spell list as regular mages, but whenever they cast a spell, it's possible for a "wild surge" to cause random helpful or harmful effects.
- The spellcasters in the Puyo Puyo series have limited control over what they cast at best, and their world is full of malicious spirits they really have no control over. Occasionally, their magic will transport them to some other country or some other planet, and they have to find a way back home. That being said, every time the heroes are transported elsewhere, it always eventually leads them to discover some Omnicidal Maniac's apocalyptic plans, whom they must then defeat.
- Roza's blood magic acts without her control.
- Goblins has the magic item named the Shield of Wonder, which causes a random magical effect when being hit. Most of them are beneficial to the user of the shield (i.e. they harm the attacker), but are very often dangerous to him, too.
- In Roommates also its Spin-Off Girls Next Door magic is... fickle. As an acknowledged plot device it's highly susceptible to the powers that shape these comics, mostly the Theory of Narrative Causality and Fanservice. So yes. Saying something even vaguely similar to the Right Words can create a magic effect (even if it takes some creative interpreting) if the result is interesting from a narrative or fan pleasing POV. And spells will backfire if/when dramatically appropriate... except if the characters count on that or something that is.
- Dominic Deegan: In the Wild Edge Territories magic is a little unreliable thanks to the ambient magic, which also mutated the native flora and fauna into all sorts of strange and bizarre forms.
- El Goonish Shive: The reason magic has the rules that it does is because of this. There are a large number of different possible rule configurations, but if the system was set up to have no downsides or limits, it would soon collapse.
The Will of Magic: Human spells would become random, the agitated energies forming massive storms of chaos magic.
Van: That sounds bad.
The Will of Magic: Yes. People would stop using magic.
- The enigma from Phaeton is believed to be Wild Magic. If it had a caster then that caster is probably long gone by now.
- In There is no GATE; we did not fight there, magic in this universe comes from a dimension of sheer chaos, referred to as the Maelstrom. Those who use magic either naturally "dive" into the Maelstrom and simply "grab" the energy they need, or use a rigid spell structure to more safely tap into their magic. Considered a safer version of the Warp from Warhammer 40,000.
- My Little Pony: Friendship Is Magic
- Young unicorns can run the risk, when very startled, of their magic going out of control. When Twilight Sparkle (one of the most powerful in modern memory) got her Cutie Mark, her uncontrolled magic turned her parents into houseplants, turned a baby dragon into a giant dragon, and came close to leveling the royal palace. Baby unicorns are even worse in this regard, since their magic is incredibly strong but purely instinctive, and cannot be controlled by anyone — especially not the baby. This is epitomized by Flurry Heart, a baby alicorn whose inherent magic is so strong — and so prone to being released by emotional outbursts — that she caused an ancient, powerful magical artifact to shatter into pieces entirely on accident. It is unknown if this level of raw power remains in unicorns and alicorns when they grow older.
- Twilight Sparkle, a strong believer in Sufficiently Analyzed Magic, tries to figure out how Pinkie Pie's "Pinkie Sense" works in Feeling Pinkie Keen. Very few spells can teleport as Pinkie seems to, or see the immediate future, as she seems to. Even then, Pinkie wouldn't be able to use them, being an earth pony, not a unicorn. Twilight eventually gives up trying to explain Pinkie's chaotic abilities. Though later episodes do imply that the Spider-Sense may be an aspect of earth pony magic, given how other earth ponies showcase similar abilities.
- The Owl House This type of magic occurs on the Boiling Isles, with the elements literally having runes in them, and was stated to be the original type of magic early witches used before evolving their own internal magic reserves.