Geas is a Scottish Gaelic word pronounced as "gesh"; its plural is geasan. This is the spelling most commonly seen in English-language works. Geis is the Irish equivalent, pronounced the same, and its plural is geasa (pronounced "GYA-sa"). In the genitive case
, Scots Gaelic uses geis and Irish uses geas.
A geas or geis (literally "taboo") is a form of magical compulsion, curse, or obligation that originates in Celtic Mythology. Those under a geas are required to follow certain conditions or risk suffering a penalty bestowed by fate. If you have more than one such geas placed upon you, and they come into conflict, you're screwed.
A geas usually takes the form of either a command or a prohibition: "You shall do this," or "You shall not do this," occasionally followed with an "Or this will happen." In practical terms, the geas may be prophetic, bringing about its own fulfillment either through manipulation of cosmic events or by simply instilling into the subject a compulsion which he cannot resist. If the geas can be broken, and is, doing so typically brings about the death of the subject, either directly or by cosmic retribution.
However, having a geas placed upon you isn't all that bad — as long as you conform to it, it can actually make you stronger. They can also be used for a Game of Chicken, where someone goes under geas in order to goad a rival into accepting an equal or greater geas.
One of the most famous cases is that of Cú Chulainn, who was under numerous geasa, including that he must never eat the meat of a dog, nor refuse food offered by a woman. When his enemies conspired to have an old hag offer him dog meat, he was forced to break one geas or the other, which led to his death the next day.
Compare: The Fettered and Obstructive Code of Conduct (for mundane versions of this), Magically Binding Contract (which can have similar effects but is more of a deal rather than a spell or curse), No Man of Woman Born (for when this is a prophecy rather than an oath), Rash Promise, and Restraining Bolt (where an object produces similar effects).
Not to Be Confused with a Geass.note Or 'geese' (plural for 'goose') for that matter.
Examples:
- Bleach:
- Giriko and his Time Tells No Lies ability. Essentially, it's a contract he invokes on himself or on others, with the spirit of his watch. It can take multiple forms; increased strength, the power to kill by line of sight, and so on. The catch is that no party involved can violate this contract, or they'll be incinerated—the part that makes it a Geas. Wonder what ever happened to Giriko's eye? Sadly, Giriko doesn't see much action.
- Zommari the 7th Espada can deal a spell from any one of his 50-something eyes and controlling whatever he hits with the spell. If he hits your head, he gets your whole body.
- Code Geass: The name of the powers is inspired by this, and Lelouch's ability is similar - he can give anyone a command that they will be compelled to obey. Being under Lelouch's Geass differs from a Geas in that the person doesn't have to remember to follow that rule — they simply enter a trance, and do as they are told. Afterwards, they have no memory of it. There are no consequences for breaking it because breaking it is impossible unless another Geass user, or the Geass canceller, does something to stop it. The "Geass" powers in this series are based on the receiver's personality and desires, and can be anything that affects just the mind of the subject (e.g. by altering their memories or perception), which makes the majority of those powers unrelated to this trope, despite the name. The benefits of following geasa receive a nod when Lelouch issues a suicidal Suzaku with the command "Live on!". This has the unexpected side effect of forcing Suzaku to move and think at superhuman speed when he thinks his life is at risk, which he later exploits by learning to enter the required mental state at will.
- Danganronpa 3: The End of Hope's Peak High School: The final killing game which the members of the Future Foundation are trapped in by Monokuma has wildly different rules than previous killing games in the series, one feature being that each player is assigned a "forbidden action" that is reminiscent of a geas taboo. Some examples are "Not allowed to run" or "not allowed to open doors". Rather than a literal magic curse, the rule is enforced by a kind of Explosive Leash: if someone performs their forbidden action, their bracelet will inject a fast-acting poison that kills them in seconds. The participants initially consider sharing their forbidden actions with each other to avoid accidentally causing any person to perform their forbidden action, but then decide not to on the grounds that someone's forbidden action may be "revealing their forbidden action"; this turns out to be the forbidden action of nobody at all.
- Demon Slayer: Kimetsu no Yaiba: Muzan puts this curse upon all the demons who serve him; if they utter his name out loud, then they will die a horrifying death.
- Hunter × Hunter: Nen can be used this way to provide a power boost or to become proficient in a Nen style the user isn't normally able to master. For example, Kurapika gains the ability to conjure unbreakable Nen chains, under the condition that if he ever uses them on anyone other than a Phantom Troupe member, it will kill him. He can also embed nen spikes in people's hearts, which will kill them if they don't follow a command he gives while doing it. He manages to effectively de-power Chrollo this way, making the nen spike activate if he uses his powers.
- In the anime version of Magic Knight Rayearth, Alcyone turns out to be under this. The condition is that she'll never reveal Debonair's existence or location to anyone on pain of death. Whenever Alcyone was on the verge of talking about Debonair, she experienced sudden pain as result of the geas, which really doesn't improve her weakened mental/physical state. When she finally forces herself to tell the Magic Knights about Debonair's location (Cephiro's Underside), in the very last episode, the geas erases Alcyone from existence, and she disappears reaffirming her love for Zagato.
- One Piece: Sugar ate the Hobby-Hobby Fruit, which gives her the power to transform people into animated toys simply by touching them with her hand. Moreover, she can force toys into "contracts", which basically allow her to impose any rule she wants - usually to force toys into obeying the Donquixote family. The caveat is that she must declare the contract immediately after the victim is transformed: even a few seconds of delay (for example, if the toy runs away) are enough to make the newly-created toy immune to any contract.
- The Seven Deadly Sins: The Ten Commandments are a group of demons handpicked for their skill and power by the Demon King to lead his armies in the Holy War. They get their name from their Commandments; fragments of the Demon King's power that bestows them the ability to inflict punishments onto themselves or their enemies if they break them.
- Galand possesses the Commandment of Truth; anyone who lies or breaks a vow in his presence are turned to stone.
- Melascula wields the Commandment of Faith; anyone who shows faithlessness will have their eyes burn out of their heads.
- Estarossa (formerly Meliodas) wields the Commandment of Love (also known as "Benevolence" depending on the dub); any who face him with hatred in their hearts lose the ability to inflict harm on anyone else. This means that they lose the ability to hold their weapons, make a fist or even move to attack. The only person shown to be immune to this power is Escanor, his Awesome Ego making it so that the only emotion he has for an opponent he considers weaker than him is pity.
- Grayroad wields the Commandment of Pacifism (also known as "Thou Shalt not Kill" depending on the dub); anyone who kills in their presence will have their time stolen from them, causing them to age to death within moments. The only way anyone can width-stand the Commandment is either not kill anyone (which is hard when you're Grayroad's enemy) or if you possess eternal youth like Merlin and Ban.
- Zeldris wields the Commandment of Piety; any who shows "disloyalty" (this could mean something as simple as turning around to run away from him) will be brainwashed to serve the Demon King. Since the Ten Commandments are loyal to the Demon King and Zeldris is his personally appointed executioner, this basically means that he is calling the shots.
- Monspeet wields the Commandment of Reticence (also known as "Silence" depending on the dub); any who expresses their hidden feelings, emotions or desires will lose their voice.
- Faudrin (formerly Gowther) wields the commandment of Selflessness; any who holds a relationship built on selfish desire (like Lust or Greed) will have their identity stripped from them, including their memories and personality.
- DIE (2018): The Dictator class is "like Bards, if everyone was fucking petrified of Bards". Anytime they use a geas, it forces the victim to obey one order. Only one person at a time can be controlled this way. This limitation comes up when the dictator has a prisoner or dangerous person under the geas "do not hurt me," and thus can't use their powers for anything else.
- A Distant Soil: Dunstan is a Fair Folk, and he says he is under a Geas that he can't tell a mortal soul who he really is while he's on mortal soil. However, it applies only to soil, that is to say, the ground - which means when he's on a cruise ship or a spaceship, he can actually mention this without violating it.
- Druid (1995): This is what ultimately did in Dr. Druid. After one of his followers was murdered by Damion Hellstrom, he gained new powers, but because he didn't have anyone else with him when he did so, he didn't know what his geis was and ended up hooking up with Nekra Sinclair, a witch — who was working with Hellstrom and triggered Druid's geis, which was to never fall in love with a witch. Nekra and Hellstrom ended up killing Druid.
- The Eternals: The Principles that guide the Eternals compel them to eliminate whatever they perceive as Deviant.
- Smut Peddler Presents: My Monster Girlfriend: The Fairy Companion in "Puzzling Evidence" claims that her role in giving hints and clues without giving any real solutions is a literal curse, made all the more frustrating by her hatred of puzzles.
- Wonder Woman (1942): The oaths of the Amazons to Aphrodite act like a set of geas, though the "rule" most commonly broken (not allowing their bracelets to be chained by a man) only results in temporary weakening. The queen losing her girdle is treated much more seriously, but so long as it is recovered in a timely manner things go back to normal. On the other hand letting a man walk in the city on Paradise Island will unmake everything Aphrodite has given to the Amazons, at the very least turning them into regular mortal women. It is heavily hinted that the actual most mild effect the Amazons could hope for is the deaths of all of those who are well older than a normal human lifespan.
- The Accidental Warlord and His Pack: Aleksander is under a spell that prevents him from speaking about the Witcher experiments to anyone who doesn't already know about their existence; if he tries, he'll find himself choking on his words. However, he finds a way around this thanks to his letterbox with Milena, helping him contact the Witchers of Kaer Morhen and let them know what's going on.
- After the Fall (Miraculous Ladybug): After Adrien's Secret Identity is exposed, the Black Cat Ring is passed to a new holder, who unintentionally limits how much time Plagg can speak with Adrien when their poor phrasing activates the kwamis' compulsion.
- Alicorn: Members of The Ascendancy use Blood Magic to cast geases upon themselves, binding their voices to a "blood warden" who dictates whether any of them get to speak or not.
- Arc Corp: When Blake makes a deal with the Lady of the Lake, she's placed under a geas that prevents her from being able to tell Jaune or anyone else about what happened.
- Blackened Bluebird: Ciara places May under a geas that prevents her from fighting back... until Ciara unintentionally dispels it upon deciding that they need to give May a Mercy Kill.
- A Boy, a Girl and a Dog: The Leithian Script: Subverted in this The Silmarillion fanfic. A long time ago, a harpist and his flutist wife were hired to entertain elven King Finrod and his retinue, but the way the man was constantly putting his wife down was getting on everybody's nerves...until Finrod's steward Edrahil ran out of patience, challenged him to a music duel and won. Edrahil then said he will take the bard's voice, and the man will only regain it if he performs a very specific task (which incidentally will force him to treat his wife respectfully). Several centuries later, as his friends are recounting the story, Edrahil finds out that everybody thought he had put a geas on the bard, and he replies he did nothing of the sort. He just realized he was dealing with a gullible idiot.
Captain: Well, then. — So the mortal is staring at him in relief at his words, with an expression of awe and humiliation together that was just painful to look at, and he asks him, even more quietly, "Have I cheated, harper? Do you deny me the contest?" and the Man shakes his head, once. "Your harp is worthless to me. Is there anything in the world you value more than your music?" and again the bard shakes his head. "Then I shall take your voice," he says, "as something else you take for granted. You shall regain it, if — and only if — you drink a cupful of water taken living from these mountain freshets, drawn and borne to you by your lady's hands, as the Sun dispels the night. No chance-met hour will suffice, nor water from well or jar or unmoving pool — and no other woman may undo this binding. Only the free gift, made in mercy, of your consort's love shall set you free — or a greater Power than mine. If she will not — [...] Then you must journey to the world's end, and find the Sea, and when Arien setting, you behold the Lady's flames upon the waves, this spell of silence shall be broken. [...] Otherwise, I cannot say how long it shall endure upon you.
Ranger: What did you do to him, Sir? We never could figure it out.
Steward: [frowning] What do you mean?
Ranger: The geas. It seemed — well — rather Dark to us.
Steward: Oh. — That's why everyone was so cooperative for six or seven years thereafter. I thought it was some rare alignment of the Circles or a conjunction of the stars — I did nothing to him. The idiot did it entirely to himself. It only worked because I could See the fool would believe and obey whatever I said to him. In other words — I cheated.
Captain: Now, be fair — you'd just convinced some two-hundred-odd people of both Kindreds that they were standing on the shores of a Sea most of them had never dreamt of, let alone seen. No wonder the poor wretch was dumbstruck. - In Briar Snared
, the first fic in the Briar Stained series by Ahmose_Inarus, Sylas Briarwood initially tells Percy (his captive) that he's free to talk with his friends (via the Sending/Message spells) but not to aid them in finding/rescuing him. Later on, Sylas gets a mage to cement the prohibition, and when Percy inadvertently breaks it, he suffers massive psychic damage. By the time the geas spell wears off, it's far too late for intel to make any difference to Percy's fate.
The mage reached out and gripped Percy’s head in his hands and his voice resonated with arcane magic. “Lord Briarwood is your Master. You belong by his side and will make NO further attempts to escape, or to aid in your rescue.” - A Certain Unknown Level 0: The Magic Name system works this way; declarations made upon a magician's Magic Name are effectively carving that concept into their very soul, becoming a way of life they must follow. Unfortunately, many of these goals are so lofty that they can't actually be accomplished. When Otohime declares upon their Magic Name that they will "Be the Salvation of Those who Cannot be Saved", they unwittingly condemn themselves to suffering from Chronic Hero Syndrome.
- Court Summons (Miraculous Ladybug): When Ladybug and Chat Noir arrange to rent the apartment space above a certain tourist shop, the owner consents to be put under one of these by Ladybug: if he ever revealed any details of the arrangement to anyone, he'd be cursed with horrendously bad luck. Unfortunately, Lila learns that Ladybug can curse people and schemes to trick her into using that power against Marinette by holding a Kangaroo Court accusing her of working with Hawkmoth as Mayura.
- The Dark Queen: The Mage's Association cast one of these upon Akiko, forcing her to carry out any job that they send her. If she doesn't, the geas will activate and kill her.
- Escape Artist
: Dumbledore puts all the students under one to ensure they didn't blab about how whatever Harry had ended up into, to a point where it would be considered a Cassandra Truth. It's also illegal as it can be seen as evidence and witness tampering, as well as deliberate neglect and abuse. And using one on the child of a ministry official like Susan Bones is a very bad idea.
- Everything You Deserve
is set into motion when Ladybug lets her partner know that she's trying to find a way of breaking this enchantment upon the Miraculouses so that the kwami can be free. Unfortunately, Chat Noir isn't happy about this — he likes that Plagg is magically compelled to do whatever he wants! So he betrays Ladybug, using the combined Earrings and Ring to make several selfish Wishes in order to rewrite reality as HE sees fit. But the angry, betrayed kwami twist his words in order to ensure the results of his Wishes are exactly what he deserved rather than what he desired...
- A Growing Affection: The Blood Oath Jutsu functions as both geas and Blood Oath. Gouki uses these to turn his followers into Slave Mooks, bound by unbreakable oaths to follow all of his orders and laws like not killing or stealing. Furthermore, Gouki intends to make all shinobi swear an unbreakable oath that will ensure none of them can ever harm a civilian again on pain of death.
- Infinity Train: Blossoming Trail: Envy and spite led Sara to go out of her way to try and ruin Chloe's life, manipulating the majority of her classmates to follow her lead. Once the Unown get involved, one of her punishments for this is being compelled to confess her cruelty, writing an exhaustive account of all her actions.
- Kintsugi - Breaking Point: This is used to ensure Poor Communication Kills after Chat Noir accidentally Cataclysms Ladybug. Adrien takes this extremely hard — so hard, in fact, that he renounces the Ring. While Ladybug wants to reassure him, she's unable to do so because she doesn't know his secret identity, and Plagg is bound by the Guardians' geas from being able to tell her.
- The Last Turn: Protheana is bound by a spell that ensures her Loyalty will never decay or be reduced, unless she first breaks an oath. Boredom, misgivings, even Turnamancy, cannot lower her loyalty to her side. Turing frees her by dragging her out of a city she was ordered not to leave, while she's helpless. Even though it wasn't her choice, it's enough to count as oath-breaking and free her from the spell.
- Logic & Trickster: The Contracts employed by The Director magically compel their victims to act in certain ways. One type of Contract forces them to enforce general compliance while other victims have their personalities altered to create artificial Palaces known as "Facades".
- Long Road to Friendship: The Elements of Harmony place Sunset Shimmer under a geas as a result of her previous behavior as an Alpha Bitch. The curse makes it so Sunset always has to tell the truth when she's asked a question, and makes it so she has to do what anyone politely asks her to do, especially if they say "please". A later chapter reveals that the latter overrides the former, as Twilight asks Sunset to "please lie", and Sunset starts compulsively lying.
- Miraculous Alliance: Nathalie is under one that prevents her from talking to anyone about how Gabriel and Emilie are involved with the Miraculouses, unless she's addressing somebody who already knows. Since that includes herself, Nathalie records herself giving an "The Reason I Suck" Speech to herself, enabling the heroes to learn Hawkmoth's identity by listening to the recording.
- The Savior King, the Master Tactician and the Queen of Liberation: The Ten Elites—specifically Blaiddyd, Fraldarius, Riegan, and Lamine—are kept under a geas by the Agarthans that forces them to be their living weapons. It's not as powerful as the Agarthans would like, however, as each of the Elites in one way or another tend to "creatively interpret" their commands and even outright threaten their masters.
- In PeaceHeather's What you are in the dark (is beautiful)
, Loki is determined to be under three geases, eventually revealed to be two from Thanos (to bring him the tesseract and not mention Thanos to anyone) and one from Loki himself (to resist Thanos and not give him anything he wants).
The volva: Most of the changes are symbolic. Those sickly blades you see stabbing into his head, those are three separate geases.
Steve: Ma'am, would you mind telling us what a geas is? Some of us have never heard of any of this stuff.
The volva: A geas is a magical command that cannot be broken by the person upon whom it is placed. Holy vows are a form of geas, which the person takes on willingly. Your people have stories of men being sent on difficult quests as penance for some crime or another; those orders, 'do not return until you have found the legendary treasure' or some such, can be enforced with a geas. They can be a prohibition against a single specific act, or a sweeping command that alters a person's entire life while they struggle to accommodate its restrictions. Or both; 'never eat meat' would be an example of that.
- Howl's Moving Castle: The Witch of the Waste puts a spell on Sophie that ages her into an elderly woman; one of the provisions of the curse is that she can't tell anyone about what's happened. When Sophie attempts to do so at one point, her mouth quite literally seals itself shut.
- Sinbad: Legend of the Seven Seas: When a god or goddess gives their word, they are "bound for eternity" not to break it, even if they really really want to. We see proof of this when Eris, Goddess of Discord, strikes a deal with Sinbad: she demands an honest answer when she asks if he'll go back to Syracuse and accept a death sentence for the theft of the Book of Peace, vowing that she'll return the tome (which she herself stole disguised as Sinbad) if his answer is truthful. Sinbad answers yes, but then flees, since he believes himself to be a Dirty Coward... only to show up to submit to the execution to spare his friend Proteus's life. A furious Eris realizes that Sinbad has told the truth after all and is thus forced to give up the Book, as her self-inflicted geas means that she can't go back on her word.
- Spirited Away: The witch Yubaba uses enchanted contracts to keep her workers in eternal servitude, but is herself under a geas: if someone demands a job, she must grant their request. Yubaba complains about it with the words "I can't believe I took that oath, to give a job to anyone who asks...", but she is still bound to the rules. There's nothing stopping her from attempting to distract the person requesting employment or even outright threatening them, but so long as they keep asking, they'll be hired.
- The Craft: Legacy: Lily is bound (i.e. prevented from using magic) by the other girls due to believing that her love spell caused Timmy's (seeming) suicide. They reverse it after learning she's in danger from Timmy's real murderer, Adam. Additionally, they discuss doing it to themselves in remorse over earlier brainwashing him with another spell.
- Ella Enchanted: Ella is under one which compels her to obey not only any order she's given, but also suggestions such as by vendors to "buy this sandwich" and "try this perfume."
- Hereditary is basically about an entire family bound by a demonic geas. It ultimately dooms all of them to a horrible fate.
- Liar Liar: The main character is placed under a 24 hour geas that makes it so he Cannot Tell a Lie. If he tries to say a lie, it comes out as gibberish. If he tries to write a lie, he will write the truth. He's not even able to remain silent as an alternative to lying, and can't even ask a question if he knows the answer to the question is a lie.
- A Deleted Scene from Pirates of the Caribbean: At World's End has Davy Jones explain that the You Kill It, You Bought It aspect of his curse is one of these, which he laid himself.
- The Annals of the Chosen:
- The titular Chosen receive their supernatural powers from the ler, the spirits of the land. The ler in turn place a requirement on the Chosen that must be fulfilled, usually daily, or their power will fade. The Chosen Swordsman for example must practice with his sword daily while the Thief must steal three items.
- The Wizard Lord is empowered by talismans but each talisman is in turn bound to one of the Chosen. If he violates his station as Wizard Lord to kill one of the Chosen, the related talisman will lose power and weaken the Wizard Lord.
- Fairies in Artemis Fowl are under a geas set by their first king, Frond, to never enter a human's dwelling without permission. The idea was that fairies were mischievous and would abuse the humans. Over time, the magic has faded a little, but is still binding. At least until a certain imp warlock tears it down singlehanded for them between the fifth and sixth books, anyway.
- The Commandments from Avesta of Black and White function somewhat like this. They are a set of restrictions a character has to abide by lest they suffer some kind of divine punishment, with death being considered the most lenient. However in exchange for following these restrictions, the characters gain some kind of incredible power, often an inverse of the restriction. One character for instance has to always obey whatever order they are given provided it doesn't conflict with prior ones with the benefit being that they can execute those orders to perfection regardless of past skills and experiences.
- The otherworld beings from The Bartimaeus Trilogy are automatically compelled to obey their orders from magicians by something perhaps like an obsessive compulsive disorder.
- Bartimaeus explains that obeying the orders is necessary, since there was one djinni that refused to kill another djinni it loved. The djinni's repeated refusal to obey the order tore apart his essence and caused him to explode, destroying the prince commanding him and the prince's entire palace. Since then, magicians tend to be more careful about which djinni they summon. Also, and perhaps even more importantly, they direct the spirits they do summon to try to directly go after attacking magicians, thus avoiding such messy business. And, for their part, the spirits have learned to be more careful about forming attachments with each other.
- It's also in the djinn's best interest to just do what the magician commands and get it over with, lest the magician cast the Curse of Indefinite Confinement or the Curse of the Shriveling Fire, which is exactly as unpleasant, painful, and deadly as it sounds.
- Briar Girls: Alaric is forced to serve Katen by magic due to her having his wings.
- In the Cassandra Palmer series, the Geis is like a love spell, a magical claim that warns off any would-be suitors and compels the the two people to be attracted to each other.
- Cradle Series: Anyone is capable of making an oath on their soul, a Magically Binding Contract that will cause their power to turn against itself if they break their word. At lower levels, it's nothing but a promise with a punishment attached. At the Monarch level, such an oath can bind reality itself, forcing participants to do something that would normally be impossible, such as living at a lower stage of advancement.
- In Deep Secret, Rupert defeats one of the villains by laying a geas on him such that if he tries to use magic again he'll die.
- Discworld:
- Parodied in Sourcery, where everyone else thinks the guy under the geas is talking about geese, leading to much confusion. And then it turns out a geas really is a kind of bird.
- Parodied again in A Hat Full of Sky and Wintersmith, where Rob Anybody is put under a geas by his wife, Jeannie, to protect Tiffany Aching. It becomes a Running Gag that Daft Wullie keeps thinking Rob means an actual goose.
Rob: 'Tis a heavy thing, tae be under a geas.
Daft Wullie: Well, they're big birds. - Golems appear to be under a geas which is very similar to the Laws of Robotics. "A golem cannot harm a human" unless their writings include the addendum: "unless ordered to do so by duly constituted authority".
- The Faerie Queens are known to put these on people in The Dresden Files.
- Titania in particular put a geas on the Summer Lady, Lily, and Summer Knight, Fix, both friends of Harry's, such that they could not offer information or help to him, despite them also owing Harry a favor for past deeds. They manage to get around it, either by Harry transferring the favor (they can't help him, but they can help the person with him), or by the Lady and Knight getting creative (while Fix can't warn Harry about Summer's forces, he can make a show of threatening Harry, which still lets him know they're on the prowl).
- It's noted that there is no actual geas that non-mortal races can impose on mortals without their consent: Free Will is absolutely paramount and cannot be directly overridden. Mortals can place themselves at the mercy of other creatures through pacts, but they will almost never outright force a mortal to do their bidding, preferring to have the mortal choose to do the deed, even if doing so is the only choice available to them.note However, the faerie folk absolutely cannot resist their duties and obligations, as Molly finds out in her new role as the Winter Lady, when ordered by Mab to collect the tithe from a group of Winter Fae that consists of their children. Molly is horrified and immediately says she won't do it, which almost kills her outright. It's strongly suggested that putting a faerie into a situation in which they would have to break an oath to fulfill another oath would kill them, as Fix almost demonstrates in Cold Days.
- Creatures of Faerie are also bound to obey the laws imposed by the Queens of their respective court. While Harry as the Winter Knight is mortal and under no such obligation, the Winter Mantle certainly is: when he negotiates with a fairy, the fairy points out that as his captive, he cannot harm her according to the laws of the Winter Court. Harry says that he's not beholden to those laws and immediately loses the power of the Winter Knight, resulting in his broken back reasserting itself and making him completely helpless until he renounces his previous statement.
- We also learn that debts CAN be sold and that breaking promises can result in bad things happening similar to breaking a geas. Mab gets control over Harry because Lea his godmother gave Mab Harry's debt. Mab uses said control to cause Harry to harm himself.
- The title character of Ella Enchanted is given, at birth, the "gift" of obedience, and she has to do whatever she is told, provided the order is given in a language she understands (and she's an Instant Expert at languages).
- Fate/Zero:
- Features into the backstory of Diarmuid. He was bound to serve Fionn mac Cumhaill, but also had a curse on him that caused women to fall instantly in love with him, which is worse than it sounds: his lord's fiancee, Gráinne, succumbed to it and placed him under a geas to make him run away with her. They eventually got married with Fionn's consent, but when Diarmuid was mortally injured and needed Fionn's Healing Hands to save his life, Fionn delayed long enough that Diarmuid died. As a Heroic Spirit summoned into the fourth Grail War, Diarmuid's only wish is to be able to make up for the whole mess by serving his Master faithfully. History repeats for poor Diarmuid. His master Kayneth's wife Sola falls in love with him and tries to use the Command Seals to make him reciprocate. Then he is betrayed by Kayneth and forced to kill himself. Diarmuid dies cursing everyone involved.
- Kiritsugu Emiya convinces Kayneth to bow out of the Grail War by, as part of the terms of their deal, offering to bind himself with a geas that will prevent him from harming Kayneth or Kayneth's fiancee Sola-Ui on penalty of losing his magecraft. When Kayneth takes the deal, Kiritsugu does indeed geas himself... but the geas doesn't say anything about letting someone else harm Kayneth and Sola-Ui, who are promptly gunned down by Kiritsugu's associate.
- Forest Kingdom: Used in a couple of cases, sometimes for good and sometimes for evil.
- In the second book, Blood and Honor, Brion DeGrange was a bandit leader until he was captured and condemned to servitude at Castle Midnight. He was placed under a geas that compels him to work as the castle's head of security, and bars him from any act — drinking to excess, venturing outside, seeking female companionship — that might distract from or diminish his performance at that task. But it doesn't bar him from absolutely hating every minute of it.
- In The God Killer, the third book in the Hawk & Fisher spinoff series, it's explained that members of the God Squad have an Exorcist Stone that can destroy any Being, even one worshipped as a god. They also have a geas on them to keep them from doing it except in the line of duty. One of them, a mystic named Rowan, figures out that by inhabiting a series of homunculi instead of her own body, she can get around the geas and kill any god she pleases.
- Forges of Mars: Gods of Mars: Telok controls the monstrous Tindalosi with a technological geas that will destroy them if they feed on anything other than their designated targets. One of them violates the geas by eating the code of a random servitor, and promptly disintegrates.
- Forgotten Realms:
- During and before the Time of Troubles, Kelemvor and his family were under such a curse. Originally the curse condemned Kelemvor's family to never accept payment for helpful deeds. In Kelemvor's case, the curse flipped so that he can never do anything for anybody without accepting a fair compensation for it.
- In the Counselors and Kings series, a wizard-word oath is a self-inflicted, usually minor version — a Halruaan wizard who swears to do something "By wind and word" will be bound to follow through, though it's up to the wizard him or herself to interpret the oath. For example, when master wizard Basel Indoulur's apprentice Tzigone offends and humiliates his rival Procopio Septus, Basel swears he will "deal with her accordingly", which Procopio intended to mean "punish her" but Basel interpreted to mean "reward her", since he thought Procopio had it coming to him. More seriously, supporting antagonist Dhamari Exchelsor is bound by such an oath to never summon any creature he doesn't understand and can't control. Since his plans require him to summon Fair Folk who more than fit those criteria, he needs to manipulate Tzigone into helping him.
- Halo:
- Halo: Cryptum introduces a technological variant that can be imprinted by Forerunners on other species (the term geas being the closest word in human vocabulary to describe the condition). The Librarian imprinted one on the entire human race to make sure her husband was found and awakened at the proper time, the compulsion being that the humans present at his location would unknowingly sing a song that contained the codes needed to give his reviver passage. Some Forerunners believe that their forerunners, the Precursors, had imposed a geas on Forerunners as well.
- Halo: Primordium takes it farther. One character has to deal with rejecting a geas that forces her to go to the dreaded Palace of Pain, which would ensure her and her companions' deaths. Turns out, gei are subject to change via nearby beacons, and the ones on that particular Halo have been hijacked by the less favorable side in the Enemy Civil War.
- Another aspect of the human geas is that the memories, and eventually entire personalities, of ancient humans are carried by many humans, "germinating and blossoming" as they do/see/hear/etc. something that triggers it. It gets to the point where the "old spirits" can hijack their host's body to communicate. None of this is considered a pleasant experience, to say the least.
- Harry Potter:
- These are called "Unbreakable Vows" in Harry Potter and the Half-Blood Prince, wherein Severus Snape agrees to let Narcissa Malfoy place this spell on him as an act of good faith. It's explained that breaking the vow is fatal, but this never actually happens in the story so details are vague.
- The Magically Binding Contract that compels Harry to take part in the Tri-Wizard Tournament in Harry Potter and the Goblet of Fire is really more like this than a contract, since he is entered into it without his knowledge or consent. The consequences of breaking the contract are not explored and are a subject of much Fridge Logic.
- A less lethal example is the hex Hermione imbued into the signup sheet for Dumbledore's Army. Anyone who rats out the DA to Umbridge after signing it will have intense, painful pustules grow on their face that spell out "SNEAK", as shown by Marietta Edgecombe.
- Heralds of Valdemar:
- In the Vows & Honor stories, the sorceress Kethry's magical sword, Need, compels her to aid women in trouble, beginning with an insistent mental tugging that escalates to excruciating pain if Kethry fails to respond promptly. As noble as the intent of the geas is, in practice Kethry and her partner Tarma mostly find it enormously inconvenient given that it makes no distinctions regarding context and has almost no sense of proportion, forcing the pair to stick their noses into everything from cases of basic domestic violence all the way up to demon-worshiping cults-whether their interference is appreciated by the victims or not. It also gives them a reputation as heroes crusading selflessly on behalf of women everywhere, greatly complicating their efforts to actually make a living as freelance mercenaries since people assume they're more interested in just causes than in getting paid.
- Need's geas also prevents its bearer from ever using it to harm a woman- again with no sense of context or proportion. Kethry's granddaughter Kerowyn, who mostly manages to avoid being yanked around by the sword the way her grandmother was, nearly gets killed when she runs up against an enemy priestess in the midst of a battle and Need abruptly paralyzes her in place rather than allow her to defend herself.
- Hurog: In Dragon Bones, Oreg is magically compelled to serve whoever owns a certain ring at the time. (It's given from father to eldest son, and is unremovable until death.) He suffers severe pain if he doesn't obey, even if he's genuinely unable to do as he's told. He also suffers when he's away from both his master and the castle he's magically bound to. He's also immortal, unless killed by the owner of the ring. The implications are quite horrible.
- Inheritance Cycle: A character who swears an oath in the Ancient Language is incapable of breaking it (though they only have to obey the letter, not the spirit). What is more, a person can be compelled to swear such an oath by someone who knows their true name. There is an out, however-if who they are changes so much that their True Name in the Ancient Language changes, all oaths they've sworn up to that point are null-and-void.
- The Isle in the Silver Sea:
- Incarnates' tales compel them to do things no matter what they want, for fulfilling their roles.
- Simran can make someone freeze and stop them speaking through just a snap of her fingers.
- Vina is bound by a geas to keep her bargain with the Fae. Later when the archivists catch her she's put under another spell to make her abide by her role as a knight, which Vina has been rebelling against.
- Used a lot in The Laundry Files.
- A geas is used as a binding oath by pretty much all occult organizations for secrecy and control purposes.
- Figures prominently into the second book, The Jennifer Morgue, in which the protagonist is put under a reality-warping geas that essentially transforms him into a James Bond-esque hero. It turns out that this is exactly what the Big Bad wants, as he plans on dismissing the geas right before the protagonist is about to win and he can kill the them easily. Fortunately, it turns out the protagonist was actually playing the role of Bond girl.
- It also turns out that vampires have some natural level of resistance to geas, although extremely powerful ones can still work.
- The alfär used geas on civilization level to keep the people in hierarchy.
- In The Labyrinth Index, the Nazgul geas the whole United States to make the population forget the existence of the President, so that they can install Cthulhu as the new one.
- Legends of Ithyria: Mardyth is able to make others do/refrain from whatever she wishes by their drinking her blood when in Ithyria or just willing it when she's within the Dangar Empire.
- The Licanius Trilogy has the Four Tenets. When a Gifted activates a special Vessel and swears oaths upon it, those oaths become magically binding on all Gifted everywhere, in perpetuity. During the Augur War a generation before the story proper, one of the Gifted used this Vessel to bind all the Gifted to four oaths known as the Tenets, ending the war. At the end of the first book, Davian and Wyr work together to amend the Tenets.
- The First Tenet forbids the Gifted from using Essence to harm non-Gifted.
- The amended version permits the use of Essence for self-defense or defense of Andarra.
- The Second Tenet forbids the Gifted from using Essence to deceive, intimidate, or otherwise work to the detriment of non-Gifted.
- The amended version likewise permits the use of Essence in self-defense or defense of Andarra.
- The Third Tenet forbids Gifted from harming Administrators in any fashion, and prevents Administrators from harming Gifted in any fashion as well.
- This tenet is left unaltered.
- The Fourth Tenet requires the Gifted to obey any order given by an Administrator.
- This Tenet is abolished, as it almost resulted in the death of all Gifted.
- The First Tenet forbids the Gifted from using Essence to harm non-Gifted.
- In the Lord Darcy story "A Case of Identity", Lord Seiger is by nature a conscienceless psychopath; a very extensive geas has been laid upon him never to hurt anyone save at the direct order of his superior in the King's Service. He shows no signs of resenting this, but he clearly enjoys those moments when he's let off the leash.
- The Lord of the Rings: It can be argued that Frodo places a geas on Gollum using the power of the Ring, or that the Ring does so itself by speaking through Frodo. After an altercation, Frodo, appearing to Sam as a white-robed figure holding a wheel of fire, declares to Gollum: "If you touch me ever again, you shall be cast yourself into the Fire of Doom". When Gollum later attacks Frodo again and takes the Ring, lo and behold, he falls into the Cracks of Doom immediately afterwards. Whether this really was a geas, or a prophecy of Ilúvatar's divine intervention, or a pure coincidence, is completely unclear.
- A Master of Djinn: The false Al-Jahiz is capable of casting spells which control djinn. Under the spell, they can be forced to attack people at his order and later keep silent on what happened, letting them take the fall.
- Nettle & Bone: A Fairy Godmother with an embarrassing knack for black magic uses this for Mundane Utility, cursing a chicken to die unless it leads her to a place of safety in an enemy city. The chicken immediately finds her a good boarding house.
- Neverwhere: This seems to be what maintains the truce at the Floating Market. It can be broken, but after what happened to the last person who did, several centuries before the novel's timeframe, even the worst villains don't dare.
- In Night of the Assholes, it is shown that assholes manifest when a non-asshole fights back when provoked by an asshole, so the best way not to turn into an asshole yourself is to be the Nice Guy and not act like an asshole. Unfortunately, the parameters of what it means to act like an asshole is so nebulous that the characters argue back and forth as to what actions constitute being an asshole, such as cases of self-defense or simply insulting them, makes enduring the asshole's relentless heckling equal parts a test of patience and a fight for survival.
- October Daye: Used a lot by several different characters.
- Evening Winterrose leaves a voicemail for Toby that contains a binding, compelling Toby to solve her murder as soon as possible or the curse will literally kill her.
- The Luidaeg became what she is today due to several geasa Titania placed on her: She Cannot Tell a Lie, will always give someone what they need if they meet her price, and cannot harm any descendant of Titania.
- Similarly, Oberon bound Eira Rosynhwyr to be unable to harm any of Amandine's line.
- Eira Rosynhwyr bound Simon and the Luidaeg to be unable to tell anyone about her unless they figured it out on their own.
- In The Powder Mage Trilogy the Privileged of Adro's cabal are compelled by a Geas to kill whoever kills the king. Which is a problem for the only surviving member, Borbador, as the leader of the rebellion that ended with the king (and most of the nobility) being guillotined is his best friend's father. He circumvents this Geas later by killing the executioner who operated the guillotine.
- The Reluctant King: Jorian is under one to help Dr. Karadur on his quest to get the Kist, in return for saving his life.
- Schooled in Magic: There are many spells of this sort mentioned or shown. People are compelled to be loyal, obedient and tell the truth with them, etc.
- Secret City: There's relatively simple oath spell; break the oath and your heart will burn instantly. Judging by behaviour or characters using it, it seems like it's Loophole Abuse-proof, but only in case of oath itself — if you have transplanted heart, you're completely immune to this.
- In Clark Ashton Smith's "The Seven Geases", the protagonist is put under of a sequence of, well, seven geases. Which comes off as mind control.
- Shaman of the Undead: The shaman Ida Brzezińska must lead the souls of the dead to the afterlife, or she loses part of her own soul and somebody else dies in the place of the undead ghost. People killed by black magic are excluded from the geas, because they turn into harpies and as such can't enter the Land of the Dead.
- Snow-White-Fire-Red: The prince is cursed so that he will be unable to marry until he finds the title character. It's not mentioned what will happen if he tries; he just goes looking for her once his parents start talking about him getting married.
- Sparrow and Bright: Brunhilde has a geas that if she ever kills with a weapon she cannot use it again or be struck down by it. This leads to a lot of wrestling and also breaking weapons that she kills with, just to be safe.
- The Sulien novels feature several geases, courtesy of the Irish Fantasy Counterpart Culture.
- Played with in Terra Ignota. Chagatai believes J.E.D.D. Mason, who believes himself to be a god, placed a geas on her, which led her to put herself under a modo mundo. After she accidentally destroyed a priceless book, J.E.D.D. Mason told her that the protagonist of every work of fiction is Humanity, and the antagonist is God. Ever since that Chagatai's found herself unable to enjoy any entertainment without agonizing over that struggle, swearing off fiction forever. It's pretty clear that nothing would happen should she revise that decision, but Chagatai herself strongly believes that something unusual happened.
- In The Thrawn Trilogy, Deuteragonist Mara Jade is a former Emperor's Hand, a Force-sensitive operative answering directly to Emperor Palpatine. During Darth Vader's Heel–Face Turn at the end of Return of the Jedi, Palpatine reached out to her with the Force and planted a compulsion on her: "YOU WILL KILL LUKE SKYWALKER." This becomes a serious problem for her during the trilogy, which sees her more often than not collaborating with Luke. Loophole Abuse in the form of Mara killing Luke's clone at the climax of the third book resolves the geas.
- The Tough Guide to Fantasyland: One of these will probably occur if a Tourist is on the PanCeltic Tour. They are quite annoying, since this might force them to marry a random person or go right across the continent on a very unnecessary trip.
- The Unexplored Summon://Blood-Sign: Summoners and vessels work closely with nonhuman entities, fight a lot, and cannot be remembered by Muggles whatever they do. To cope with the stress of all that, each summoner adopts a ritualized pattern of behaviour that they almost cannot diverge from; examples include helping anyone who asks for it (and only those people), never leaving your house, only entering battles for which you will be tangibly rewarded, and making decisions based on a coin flip. The pattern may be unpleasant, exploitable, or fatally negligent, but that matters little to the person; they will always conform to it or at least spend time and effort trying to. Any divergence for any reason rattles their (already weak) sense of identity.
- The Unwanted Undead Adventurer has this in the form of a magically-enforced contract used by Sheila. It places upon her the restriction that she must be a Secret-Keeper for Rentt. If she reveals his status as undead, she will be compelled by magic to immediately quit her job as a Guild receptionist, go to a country where slavery is legal, and sign away her rights to her own person. She places the geas on herself as a show of deep concern for Rentt.
- In The Will of the Empress, Shan implies in a very squicky way that "There are ways to make mage wives obey you."
- In The Witches of Eileanan, several people are put under Geasa. Most of them are, or given them by, Khan'cohbans (like Inuit elves with ram's horns), though there isn't a spell involved, it's mostly just a task or obligation that is given social significance if one were to break it or accomplish it. It's less a spell and more a binding of honor.
- Wiz Biz: In Wizardry Consulted, a dragon places a geas on Wiz, forcing him to stay in Dragon Marches and solve the dragon problem by any means necessary. Including hiding from his fellow wizards and hacking NSA computers to keep his cover. This is only revealed by the end, explaining some Too Dumb to Live decisions.
- Worlds of Shadow: Shadow places one on Pel compelling him to do and refrain from doing various things. However, he finds a workaround against Shadow nonetheless.
- One of the Xanth books is titled Geis of the Gargoyle.
- Zeus Is Dead: Any oath sworn by the River Styx (figuratively or literally) is binding, even for a god. Hermes even wiretaps the Styx so he can spy on anyone who utters such an oath in secret or in unthinking rage, and uses this to blackmail Zeus.
- Misfits: A young Roma woman puts a curse on Alex after he refuses to help her retrieve something that had fallen in the water. It makes him help everyone who asks, or he'll have to feel like he's drowning. Finn quickly exploits this by making Alex lend him money. She takes it off after he shows contrition.
- The Wheel of Time (2021):
- Aes Sedai are bound by magic to keep three oaths stopping them from lying or harming others (absent some extreme circumstances) with their powers. It was done in hopes this would make them more trusted by people, but that hasn't worked out very well (given they find a lot of loopholes with the oaths, to start).
- Later we also see the Oath Rod, which is a kind of magical device which has this effect on any person touching it. Any oath they swear when doing so is completely compelling for them. Moiraine swears to leave Tar Valon and only return if invited back by the Amerlyn while doing so.
- Samson in the Book of Judges of the Old Testament was bound to the terms of the Nazirite vow
(he was not allowed to partake of wine or anything else made from grapes, touch a dead body, nor cut his hair) due to a promise made by his mother; breaking the vow would result in the loss of the super strength God had blessed him with. Sure enough, when Delilah, who had been hired by the Philistines to trick him into revealing his secret weakness, shaved him bald, he was left defenseless and promptly taken captive. It turned out the effect was as temporary as his baldness. By that point Samson had already broken the other terms of the Nazirite vow. The hair-cutting was just the last straw.
- This is all over the place in Irish Mythology:
- Diarmuid O'Duibhne was "under geis" not to hunt the Boar of Ben Bulben. But Fionn McCumhaill tricked him into participating in a hunt that tracked the very same boar, and the boar killed Diarmuid.
- Cú Chulainn was under geasa never to refuse an offer of food, and never to eat dog meat. Of course, eventually his enemies offered him dog meat. He ate, and was killed soon afterwards.
- Cú Chulainn's son, Connla, was placed under a three geasa: to never turn back on a journey, to never turn down a challenge and to never give his name. This leads to Connla seeking out his father when he came of age, only to die at his father's hands when refused to speak his name. Depending on the version, the one who put the geis on him was either his mother who did not leave Cú Chulainn on the kindest terms or else Cú Chulainn himself.
- High King Conaire Mór was under a whole host of geasa. Eventually events conspired to make him break all his geasa in a single day. The same night, he was killed by sea-raiders.
- The Children of Tuireann: Lugh of the Long Hand is under geis never to refuse a second request. The sons of Tuireann exploit this when he sends them off on a quest to redeem themselves for killing his father. First, they asking Lugh to lend them the horse of Manannan, which he refuses, then ask him for the boat of Manannan, which is what they actually want.
- Dice Funk: In the second season, Lorelei has this as a central plot point and one of the main things keeping the Driving Question a secret. Anyone who makes a deal with Zavala is unable to talk about it in specific terms without dying from the geas. It can be removed with a spell, but it also removes any replaced body parts provided by Zavala, which can be potentially fatal.
- In The Gamer's Alliance, the archdemon Malphas ends up under a geas when he kisses fellow archdemon Nina Heeate's enchanted ring, and the geas forces him to serve Nina's every whim. It turns out that Nina was using magic and her female physique to mess with Malphas's mind, which confused Malphas enough to make the geas take effect. Nina doesn't keep Malphas on a tight leash, however, and instead lets him do what he wishes as long as he doesn't stand in her horde's way. The geas also requires Malphas to keep his mouth shut about the whole endeavor, further ensuring that Nina's part in the whole mess stays out of the limelight.
- 7th Sea has the geas, a special ability that can be purchased at character creation. As long as you have the geas, it gives you an extra experience point each session, but if you fail its condition you lose the geas forever.
- Dungeons & Dragons:
- The geas spell forces the character to fulfill the terms. Refusing to do so (even unintentionally) can carry some nasty consequences. Clerics call the same spell "Quest", and also have a "Mark of Justice" that places a curse on a character who breaks the conditions of the Mark.
- The powers of Wu Jen and characters under the various Vows of the Book of Exalted Deeds have specific behaviors or tasks they must perform to maintain their powers.
- Exalted: The Primordials placed one on their creations, the gods. It forbade them from directly attacking any Primordial (except in self defence or on the order of Theion). The gods got around this by giving power to mortals whose free will means that their actions are seen as sperate from the gods. They were then free to help these humans as long as they themselves didn't attack a Primordial; anything else was fair game.
- Kitsune: Of Foxes and Fools: "Geased" is a consequence that prevents a fox from regaining foxfire for two turns.
- Mage: The Awakening: Geasa can be inflicted by mages who have gained Mastery of the Fate Arcanum. Working against the terms of a geas (or even failing to actively do something required by the geas) inflicts a very debilitating curse. A geas (and the curse for breaking it) can be made hereditary, affecting the subject's descendants as well.
- In Nomine: The demonic lilim can look into a person's eyes and discover their true desires (ranging in intensity from "needs a light for their cigarette" to "needs to save their lover's life"). If they then fulfill one such desire for the person, they can attempt to attach a geas to the person to do something in return. They're limited only by the scale of the desire (an easy-to-fulfill desire would grant a geas that only lasts an hour or so) and the target's ability to resist the compulsion. The dangerous part is the target is usually not aware that the lilim is doing this, and doesn't have to agree to a Deal with the Devil for the lilim to get the geas. The only real defense is a combination of never looking a lilim in the eyes (or using sunglasses), and never accepting anything they offer, ever.
- RuneQuest: Worshippers of Yelmalio can take on geases in exchange for divine blessings. These include a variety of dietary restrictions, limitations on armor or weapon use, partial or total celibacy, vows of enmity aganist enemy gods, dwarfs, Darkness creatures, or Orlanthi, and the like. In exchange, as long as the geas is observed, he grants a variety of mundane and magical gifts.
- Shadowrun: Geasa are used in 3rd edition to recover points of magic that are lost by shaman/magicians/adepts. Your character has to accept some sort of condition to recover a point of magic. Usually this is anything the GM wants/is willing to allow but classic ones are some sort of talisman that you have to keep on your person, having to fast on a regular basis, spending time in meditation, or only using magic in certain circumstances. Breaking the geas reduces your magic back to its normal level.
- In Into the Woods, the Witch requires the Baker and his Wife to track down items to create a potion, ostensibly to lift a spell she placed on their family that has rendered them unable to have children. At the end of the first act, it's revealed that the potion will also break a curse of age and ugliness on the Witch herself. That curse comes with a geas: she can't touch any of the ingredients, which explains why she hasn't been able to break it of her own volition.
- In the second Avernum trilogy, especially in the fifth game, your party can get a geas from three different parties: Gladwell will put one on you (in exchange for his aid) that will force you to carry out his research... usually involving killing innocents and making whole communities hostile to you. Then there are the Anama Church: joining them will have you renounce to your sorcerer's spells and access freely to their base, but it can also compel you to fight other sorcerous NPC which are enemies of the Anama. Finally, the imperial sorcerer Shafrir will put a lesser geas on you (giving you a warning) that will give you a massive malus if you attempt to fight him. He can also try to release you from previous geas and wants you to recover the sacred Anama scrolls to study their geas magic.
- Yoshimo in Baldur's Gate II is under a geas to betray you at a certain point of the plot.
- In Dragon Age: Inquisition, an Inquisitor with Arcane Knowledge can figure out that Abelas' warning that the Well of Sorrows' power comes with a price isn't hollow: anyone who drinks from it is put under a powerful geas. Morrigan is dismissive of the geas since she believes that Mythal is long gone. Then it's revealed that Mythal is Flemeth.
- In Final Fantasy XIII, l'Cie are humans unwillingly branded by a fal'Cie, granting branded humans with new power in exchange with bestowing a task - a Focus - for them to complete. The problem, however, is that fal'Cie don't even bother to tell l'Cie what their Focus even is, leaving them completely in the dark about that they need to do before their brands turn them into mindless Cie'th. And if they somehow manage to complete the unknown task? They're still rewarded with getting crystallized. The fal'Cie can also exploit a nasty loophole by branding people as l'Cie without giving them an Focus; the resulting Logic Bomb causes those branded with such to turn into Cie'th immediately for an instant zombie army should a fal'Cie so desire.
- Fire Emblem:
- In Fire Emblem: Thracia 776, it is revealed in the ending that Eyvel, actually Brigid from the previous title, had her memories sealed away in a geas with ancient dragons, likely in order to live through The Battle of Bellhalla. Her memories returning bring a Happy Ending.
- In Fire Emblem Fates, the Curse of Valla can be seen as a geas. After Anankos took over, he places a spell under the land: if anyone who's been there and returned to the other lands tries to talk about it outside of Valla's territories, their body will dissolve into water. As a result, in the past Azura's mother Arete, the former Queen of Valla and later the Queen of Nohr, pretty much killed herself to tell a young Azura about Valla itself so she would keep the knowledge about it, and Azura could not properly tell the Avatar about Valla until the Golden Path took place.
- In God of War (PS4) After discovering that Baldur was Freya's son, Kratos and Atreus asks Mimir why he never told them beforehand; and wondering what was Baldurs' weakness was only for Mimir to constantly repeat that Baldur "Was Invulnerable to all threats Physical or Magical"; leading to Kratos to realize that at some point in time Freya had bewitched Mimir to not reveal any information that he knew about Baldur to anyone.
- Continuing from the Halo plot thread mentioned in the "Literature" section, Halo 4 has the Librarian imprint mentioning to the Chief that a good part of the UNSC's advancement, including Cortana's design and the Chief himself, has to do with the geas she implanted into humanity over 100,000 years ago.
- In Neverwinter Nights: Hordes of the Underdark, as a way of avoiding the But Thou Must! faux-choice, the player character gets a geas to kill the evil sorceress Valsharess.
- In Quest for Glory IV, the Hero is placed under a geas by Katrina, giving him three days to recover the rituals needed to free the the Dark One. The geas is removed once he returns successfully with them.
- In Tales of Berseria, a geas is placed on Bienfu, forcing him to act as The Mole to Velvet's party and leak their actions to the Abbey. It's a powerful enough geas that even Magilou can't detect it until she catches him talking to a sylphjay as they sail towards Titania.
- Referenced in Wild ARMs 3 - Janus, after acquiring his demon form is bound to follow the Prophets' instructions, under pain of being blown apart by the remote bomb called Geas.
- Yes, Your Grace: King Eryk and Queen Aurelea are under a spell that, among other things, keeps them from having a son in a setting where sons-in-law can inherit unless Eryk honors his promise to marry his oldest daughter to Beyran. One of the game's biggest side-objectives is to gather material for a ritual to conter the most inconvenient effect of the spell, then accomplish it.
- Lancer in Fate/stay night, whose true identity is Cuchulainn himself, has a geas that if a man from Ulster uses Caladbolg against him, he must lose the fight, but it never happens. The sequel, Fate/hollow ataraxia has Shirou play a trick on him involving his original two geas, though they are never stated outright: Three female friends of his from school offer Lancer a hot dog, an offer he can't refuse and (were it actually dog meat) something that could potentially kill him. This is actually related to how he originally died.
- At one point in Unlimited Blade Works, Rin threatens to use Geas on Shirou. One bad ending in Heaven's Feel occurs when she follows through on her threat, placing Shirou under a Geas and using it to stop him from saving Sakura.
- In Fate/Zero, Kiritsugu uses one to eliminate Lord El-Melloi as a Master: he kidnaps El-Melloi's fiancée Sola-Ui and threatens to kill her, unless El-Melloi orders his Servant Lancer note to commit suicide, removing himself from the Holy Grail War, in which case Kiritsugu will geas himself into never harming El-Melloi or Sola-Ui. El-Melloi accepts (as a magus himself, he can see that the self-geas scroll Kiritsugu is holding is genuine), and then... Kiritsugu's partner Maiya immediately kills both El-Melloi and Sola-Ui... after all, Maiya wasn't under a geas to do them no harm.
- In Soul of Sovereignty, the Magically Binding Contract that Loïc invokes grants unto Ysmé the power of a god, but has a few unique effects on him, as well. From now on, he will be compelled to carry out Ysmé's will, no matter how high the cost. Even when the invocation was only halfway complete, he had trouble stopping himself from assaulting a police officer after Ysmé joked that he ought to throw a chair at the man — "willing hands," indeed.
- Immortals are able to inflict this on themselves by making a vow in El Goonish Shive. Even so much as considering breaking a vow results in intrusive thoughts telling them to keep it
. If they irreparably break a vow, for example: vowing not to kill someone, and then killing them, the resulting cacophony of thoughts about breaking their vow would be debilitating. And given that they're immortal, they may be stuck with this for a very long time. The vow is also capable of carrying on to their later incarnations should they so choose, much to Zeus' chagrin.
- One of the powers that Acanthus Mages such as Amical or Tyler have in morphE.
- In The Order of the Stick, Belkar is put under a Mark of Justice which prevents him from dealing lethal damage (a D&D rules term, basically meaning any damage that isn't the kind you'd use in a sport fight — and Belkar never bothers with sublethal damage when he can get away with lethal) to any living thing within the bounds of a settlement. He also cannot travel more than a mile from Roy, on pain of suffering from a sickening curse. The curse is eventually invoked when Belkar stabs the Oracle, who had established a village around his tower for exactly that purpose, and then removed by a cleric who needed Belkar to protect him from an invading horde of goons.
- SCP Foundation: The Foundation has usese them occasionally, usually whenever they need to silence someone who's too valuable to amnesticize. The UIU(seless) are subject often enough that they have their own nickname for it, "Gag Orders".
- Life SMP:
- In Last Life (Season 2), Limited Life (Season 4), and Past Life (Season 7), the Boogeyman curse functions along the lines of one: the inflicted player(s) must kill another player to cure themselves or face a penalty relating to their lives the next day — being reduced to their final life in Last Life and Past Life, and dropping to the next colour grade in hearts (i.e. losing up to a third of their original life-time) in Limited Life. So far, exactly two players have been penalized for failing to commit the mandatory murder upon being cursed, with one refusing to do so out of Undying Loyalty in Last Life and the other simply being extremely unlucky in Past Life.
- The personalized secret tasks in Season 5, Secret Life SMP, must be fulfilled to counter the Anti-Regeneration gimmick of the season. If a player fails their task, they get no hearts at the end of the session. If a player fails a rerolled harder task, they lose 10 hearts.
- On Day 3 of Past Life, the three members of the Secret Society are instructed to collaborate to kill two other players by non-PVP means, or else they will each lose two lives the following session.
- Naked And Afraid SMP: In the first episode of Season 2, each player gets a book from The Game Master giving them a test: to acquire a diamond pick and travel 12,000 blocks to make it home. While the books don't specify what will happen if someone fails these tasks, the players know that there will be a consequence. As it turns out, the penalty is to lose a permanent heart, leaving SB737 with a max health of only 9 hearts after Episode 1. This penalty is also mistakenly given to all surviving members of Blue Team at the end of the episode, which is fixed at the beginning of Episode 2, along with a small gift and apology from The Game Master.
- Fangbone!: The episode "The Breaker of Oaths" has the Skullbanian Oath-Vow, where the involved parties must fulfill their respective sides of the deal that they make with each other, with a terrible and unpredictable punishment befalling those foolish enough to break it. Examples include one barbarian becoming irresistibly delicious to dragons, another having his head turned into a giant fist, and Bill receiving an evil Split Personality named Will after he breaks the Oath-Vow he makes with Drool. Fortunately, the curse can be lifted if the Oath-breaker eventually and successfully fulfills their end of the deal.
- In Freakazoid!, a character who must not be named has the power to kidnap children, but only if they say his name out loud. At one point in his debut episode, he's in a bunk at a camp filled with kids, but is only able to speak to and interact with the ones who are foolish enough to say Candle Ja-
- Gargoyles:
- An unusual example; Demona once used the Grimorum, a powerful book of magic, to place Goliath under a hex compelling him to obey the spoken orders of "whoever held the spell." Brooklyn seized the book from her, found the page with the compulsion charm, and tore it out before Demona could reclaim it, so that Goliath would follow his orders instead. After the pair defeated Demona, Eliza found a Curse Escape Clause: she holds the page and commands Goliath to act as he would if he were not under a spell from then onward. So essentially, for the rest of the show's run, Goliath was under a geas—to be himself.
- There are also Oberon's Laws, which members of the Third Race have to follow. Sometimes it's portrayed as if they have no choice, other times they can and just risk Oberon's wrath.
- Notably, there is a case where one rule contradicts another, but in this case it's used for Loophole Abuse: the Weird Sisters aren't allowed back on Avalon, but they're required to listen to any mortal whom they agree to serve. They thus make an alliance with the Archmage, knowing that he'll order them to go to Avalon.
- The immortals from Highlander: The Animated Series are under one of these, having all taken a mystical oath to never be able to kill another immortal. Of course, Kortan waited until all the others had taken the oath and then didn't, effectively rendering him invincible to everyone who could ever stand against him. Didn't really think that one through, did you guys? A couple of the immortals, known as Jettetors now, have figured out ways to weasel out of the geas: Cornell changed his name to "Orion" since the oath mentioned them by name specifically, Matsuda built a cyborg to fight on his behalf, and of course the main character Quentin was born after the fact and thus never took the oath in the first place.
- In Miraculous Ladybug, the kwamis are magically compelled to obey their human masters, and are forbidden to speak their masters' names to each other. While Marinette and Adrien are Incompletely Trained and unaware of the extent of this, Hawk Moth is very much aware, at one point using the geas to remove his kwami's mouth because Nooroo wanted to go celebrate his birthday.
- Pearl of Steven Universe, in several episodes, can be observed slapping her hands over her own mouth when certain subjects come up in conversation. It's revealed late in Season 5 that this is under command of her original owner, Pink Diamond, to never again speak of how the two of them faked Pink Diamond's shattering at the hands of "Rose Quartz", who for that instance was Pearl in disguise, but otherwise was actually Pink Diamond herself. Thankfully, Pearl finds a way out through Exact Words: since Pink commanded her to never speak about the incident, she instead shows Steven, Pink's son, the truth via an interactive memory. Once he's witnessed it, the "spell" is broken, and Pearl can freely and happily give the backstory on why this happened.
- Eliza on The Wild Thornberrys was given the ability to speak to animals, on the condition that she never reveal it to another person. If she ever tells anyone, she'll lose the gift. On at least one occasion, she spoke with Darwin (her chimp) in front of another person but passed it off as vocal mimicry "to calm him down" without violating the terms. When she does reveal the secret to save her sister's life, she loses the gift immediately. When she eventually earns it back, Debbie is placed under her own geas: if she reveals the secret, she'll be turned into a baboon.
