What was sundered and undone
Shall be whole, the two made one
By Gelfling hand, or else by none.
A fantasy world where all prophecies are mandated by the Universal Laws to be 100% accurate easily lends itself to reveal-the-plot prophecies, particularly when the author isn't skilled in the fine art of obfuscation and Prophecy Twist. However, laying out the plot beforehand is a good way to kill any plot tension. All but the most incompetent of authors realize that something has to be done.
As its name implies, an Either/Or Prophecy specifies two possibilities. Either the good will triumph over evil or the Big Bad will mop the floor with the pesky heroes and reign unconquered forevermore. The point is that there is no middle ground.
It is implied that each of the possibilities has a 50% chance of coming true, but in practice, the good will always triumph and the evil option is just there to motivate the characters (and distract the audience). Occasionally, through a Prophecy Twist, both halves come true. And it's always possible that the heroes might say "Screw Destiny" and Take a Third Option.
A little thought reveals that the inverse of this trope, when applicable, falls under No Man of Woman Born. The latter trope requires that two or more conditions be met that are supposed to be contradictory (and thus interpretable as Neither-Nor)note note , but in reality aren't, leading to the inevitable Prophecy Twist.
When the Either-Or Prophecy is split into two opposing prophecies, it forms a Prophecy Pileup.
See also Either "World Domination", or Something About Bananas, which is when the prophecy only states one thing will happen but translations aren't sure what that one thing is.
- Naruto has the head frog sage of Myobokuzan foretell that one of Jiraiya's pupils will either change the world for the better or bring the world to ruin. The possible candidates are Naruto and Pain/Nagato. Nagato ends up endorsing Naruto as he performs his Death Equals Redemption in order to resurrect all the victims of his attack on the Leaf Village.
- A Spider-Man annual, "Night of the Bend-Sinister", begins with a prophecy from the Book of the Vishanti, stating that once every 60,000 years a mystical conjunction called the Bend-Sinister is possible, and at that time demons will succeed in invading the Earth unless "a mighty sorcerer'' joins forces with "one who both spider and man". Fortunately, Spider-Man and Doctor Strange are old friends...
- In the Tom Strong story with the interdimensional Aztech Empire, the computer-god Quetzocoatl-9 tells the High Priest that if he invades the world with superhero Tom Strong on it "there will be a great victory". The victory in question was Tom Strong destroying the hardwired controls that left Quetzocoatl-9 enslaved by his priesthood. Thus the computer-god destroyed the priest and took direct control of his empire.
- Believe in the Weird and Wild: The king and queen discover an old scroll detailing a prophecy that one day, their children will come together and bring either everlasting peace and light, or unleash never ending chaos and darkness. They've apparently told said children about it, but either Star wasn't listening or just misinterpreted it, as she thinks the prophecy is about her eventually falling into darkness that Quartz will have to save her from.
- One Norwegian folktale has a village idiot make his way to fame and fortune via well-timed ambiguous statements. The last test set before him by the king is to predict the sex of the queen's unborn child; he has her walk towards and away from him before declaring, "When she walks towards me it looks like a boy, but when she walks away it looks like a girl." She gives birth to twins.
- In Disney's Hercules, the Fates foretell that Hades will overthrow Zeus at a time when the planets align perfectly unless Hercules fights to stop him. Hades spends most of the rest of the movie doing his darnedest to kill Hercules before the deadline.
- In the film The Dark Crystal, there's a prophecy which states that the eponymous crystal can only be healed during the conjunction by a Gelfing. The Skeksis massacred the Gelflings to prevent the healing of the Crystal, following the logic that so long as no Gelfling was alive at the conjunction, nobody could repair it. They missed two.
When single shines the triple sun
What once was sundered and undone
Shall be made whole; the two made one
By Gelfling hand, or else by none.
- In The Matrix, the Oracle examines Neo and says, "But you know what I'm going to say, don't you?" "I'm not the One," he says. The Oracle tells him that he has the gift but that he seems to be waiting for something. "Your next life, maybe." She then tells him that, soon, Neo's life and that of Morpheus will hang in the balance, and that he can save himself or Morpheus. Because Neo believes (but the Oracle did not confirm) that he is not the One, Neo chooses to save Morpheus. Neo dies and arrives in his next life once he disbelieves the reality of the Matrix.
- The Bible kinda has one of these in 1 Kings 19:17, with God giving Elijah a kind of "flow chart" prophecy: any of the apostate Israelites that the king-to-be Hazael of neighboring Aram doesn't slaughter with his armies, the king-to-be Jehu of Israel will finish off. Anyone who escapes Jehu, Elijah's own successor Elisha will put to death. Each prophecy was then fulfilled in following chapters except for the part about Elisha because it proved unnecessary; so far as the book indicates, Elisha never had to execute anyone himself because nobody escaped King Jehu's zealous purges.
- In The Chronicles of Thomas Covenant, Thomas Covenant is prophesied to "save or damn" the world. This is actually only one of a long list of opposites that are prophesied to apply to Covenant, and the whole effect comes out to "we don't know if he's going to be a good guy or a bad guy, but he's definitely important."
- The Belgariad by David Eddings has this trope as the underlying premise of the whole series. There are two competing prophecies which, combined, amount to one big Either-Or Prophecy (one of them says Belgarion will defeat Torak; the other one says Torak will rule the universe, though it turns out that Torak actually has a "we can rule the galaxy together as father and son" scenario in mind). In the sequel series, the same continues in a slightly tweaked form, so that the winning future is determined by one person who is supposed to be totally impartial.
- Harry Potter:
- The prophecy at the heart of the novels does not describe the eventual triumph of good over evil, but instead simply declares that Harry and Voldemort are destined to battle each other to the death. The aftermath of that battle is not something with which the prophecy is concerned.
- In Order of the Phoenix it is revealed that when the prophecy was made, it specified a child who could be either Harry Potter or Neville Longbottom, and only Voldemort's actions settled it on Harry.
"Neither can live while the other survives."
- Almost all important prophecies in Terry Goodkind's Sword of Truth series of novels are of this type. The fourth book puts a twist on this, as both possible fates seem to require the hero's death...
- The very same prophecy also mentions his beloved will betray him. She has to betray him (and it is foretold that she will do so) in order for him to enter the Temple of the Winds through the Path of the Betrayed. And she does. Once she realizes, she begs the only witness not to tell Richard. The witness's response: "I think 'Richard' already knows."
- It's also worth noting that the final equation prophecies for both good and evil prove true by the end of the series. Magic is saved and destroyed when Richard spits the world in two and creates a new "no magic" world for the communists to live in.
- In The Last Rune series people are trying to save or kill Travis since he's fated to both save and destroy the world (usually based on how optimistic they are). Turns out he destroys the world then rebuilds it exactly the same only without the Big Bad.
- Depending on what happens to the Lightstone in the Ea Cycle, either an Age of Darkness would start and a monster would destroy most of the universe or The Chosen One would bring about an Age of Light and lift everyone to a higher state of existence.
- In Night World, the Wild Power prophecies specify "Four less one and darkness triumphs", which is widely taken to mean that unless all four Wild Powers are working together to stop the Night World from taking over, then humankind and Night People who support them are stuffed.
- The Wheel of Time has one of these among a hundred. For the most part, Min's viewings are unavoidable, thus making them useless as prophecies; whether she tells them or not makes no difference. But there are a couple that are conditional. Interestingly, from a certain point of view both options could be seen to come true:
- Gawain will either kneel to his unofficial girlfriend Egwene, or kill her. He kneels, though he is also largely responsible for her death
- Min's viewing of Siuan Sanche and Gareth Bryne said that "You must stay close to each other or you will both die." They end up saving each other's lives after an assassin carrying a poisoned needle attacks them (Gareth kills the assassin and Siuan heals him from the poison). Later, during Tarmon Gai'don, they are separated, and just after Min reveals that the viewing is still in effect, Siuan is killed in an attack. The effect of the warder bond makes Gareth go berserk and get killed.
- The various viewings of the future beyond the Last Battle, including Min's, qualify as well. They're accurate readings of The Pattern that shapes the past and future. However, if the Big Bad wins, The Pattern itself will be destroyed, rendering the viewings false.
- Also used in one of the prophecies regarding Mat Cauthon, who was told "You will go to Rhuidean." He asked the prophet, "Why do I have to go?" and was told "If you do not, you will die." Mat could theoretically tell his destiny to screw off, if he was willing to die for it and possibly doom the world.
- This is seen somewhat in Dune, where Paul and later Leto II can see possible futures and must choose the best one to carry out.
- In Percy Jackson and the Olympians, there is a prophecy that a half-blood child of one of the big three will either save the Olympian gods or damn them... or so we believe for the whole freaking series. what it actually says is that when the next child of the big three turns 16, a hero will make a choice to save or damn the Olympian gods...this hero and the halfblood aren't the same person.
- In Warrior Cats, a prophecy says, "Fire alone can save our clan". It doesn't specify whether it will or not, just that it's the only thing that can.
- The second series of Wings of Fire has the Jade Mountain prophecy, which says that either "Jade Mountain will fall between thunder and ice" or the Lost City of Night will be found.
- The The Darksword Trilogy revolves around one, though initially no one is aware of this information, as the prophet who delivered it died before he could finish.
- There will be born one to the Royal House one who is dead yet will live, who will die again and live again. And when he returns, he will hold in his hand the destruction of the world... ...Or its salvation.
- Subverted in the ancient Terris prophesies in Mistborn, which says that the Hero of Ages will have the power to save the world, but also the power to destroy it. It doesn't mean that the hero will either save or destroy the world, it means that the hero will bear the two powers of Preservation and Ruin, both of which are required to save the world.
- The key prophecy in First Wave from the Lost Quatrains of Nostradamus:
On the seventh dawn of the seventh day;A twice-blessed man will roam the fields.Doomed to shadows with his brethren;Or savior to all who walk the ground.
- Basically, it's up to Cade (the "twice-blessed man") whether Earth will be conquered by aliens or not.
- The Shanshu prophecy in Angel says that the vampire with a soul will either save the world or destroy it during the Apocalypse.
- Lexx has the Time Prophet basically state that a Brunene-G will destroy His Divine Shadow. So, of course, HDS kills all of the Brunen-G... Only to turn the last one into a Brainwashed and Crazy undead assassin. It was a specific case of His Shadow trying to Screw Destiny, since He never thought that Kai would recover from being brainwashed (not so much the undead bit), nor that Kai would just so happen to have a brain-eating Cluster Lizard handy when His Shadow transferred back into the body of a planet-sized Insect. Although the prophecy itself is cut and dry, it falls into this trope because the Time Prophet specifically makes her predictions by looking "more or less into the cycles of Future-Past", which basically means "Since all this happened this way before under different names, it will happen again, probably, unless it doesn't".
- On Vikings the Seer is fond of those and will rarely give anyone a straight answer to their questions. He tells Ragnar that if he defeats Jarl Haraldson it will be a sign that the gods favor him and thus his rebellion is not a crime. If Haralsdon wins then it means that Ragnar was obviously not favored by the gods and had to be punished for his crime. Since it is highly unlikely that the two men will reach a peaceful resolution, one of those two outcomes is inevitable and thus the Seer will be proven correct.
- Candorville parodies this during The Reveal. If a vampiress can produce a Dhampyr, which Roxanne managed to do thanks to modern fertilization techniques, she'll lose all the standard weaknesses and the need for blood while retaining all the assets. It's prophesied that she'll someday rule over mankind... unless she gives into her still-existing desire for blood, in which case she'll be returned to normal having gained nothing. "And her APR would shoot up to 29.97%."
- SJ Games' In Nomine RPG features the Archangel of Destiny, who knows with divine certainty that ultimately everything will turn out all right... and the Prince of Fate, who has an equal certainty that Hell and the forces of evil will triumph. Fate and Destiny hang in a sort of metaphysical eigenstate over any sort of prophecy in this setting, and as angels and demons, the player characters themselves are often the 'spooky action at a distance' that resolves them.
- The Usurpation of the Solar Deliberative in Exalted was triggered when the Sidereals read the Loom of Fate and noticed a gigantic celestial clusterfuck would ensue if the Solars kept doing things as they were. They could either tell the Solars about this and hope that they'd yield to the advice, or overthrow the Solars and ensure that the crisis did not come to pass. They chose the latter, which had its own string of nasty side effects. The best part? Due to the manifestation of the Great Curse upon the Sidereals, the choice to kill them all did not avert the dark and miserable future that would come if they failed to persuade the Solars — it only delayed it, and if not for the careless arrogance of the forces of Evil, there wouldn't have been any Solars to stand in the way.
- The Draconic Prophecy in the Dungeons & Dragons setting Eberron can be said to follow this trope; it describes the inevitable results of certain events, while remaining silent as to whether these events will ever happen. This works out perfectly for adventures: If event X happens, event Y will happen. If you want to prevent or cause event Y, you've got to worry about event X.
- The game Super Paper Mario revolves around a prophecy of multiversal destruction written in a book called the Dark Prognosticus; this is rivaled by a prophecy that the multiverse will be saved by a band of heroes, as written in the book's Good Counterpart, the Light Prognosticus.
- This one gets a bit confusing: both books predict almost exactly the same set of events coming to pass; the Dark Prognosticus mentions a band of heroes fighting for the multiverse's survival as well. Eventually it is revealed that the Light Prognosticus isn't prophetic at all, but was written "to counter the Dark Prognosticus", suggesting that it simply contains the same prophecy but with a rewritten outcome. Or instructions on how to make the favorable outcome of the Dark Prognosticus's either or prophecy (which is never mentioned that it has) come to pass. Since the Light outcome happens in the end anyway, the suggestion is that even if the Dark was truly prophetic, The Power of Love can Screw Destiny. One prominent Epileptic Tree is that the Dark Prognosticus was written by the Dragon with an Agenda as part of an elaborate plan, rather than actually predicting the future. The writers have not commented on this.
- One of the plot points in Metal Gear Solid: Portable Ops revolves around a pair (well...) of twin psychics, one of whom sees the main character destroying Metal Gear, the other of whom sees the main character starting a terrible war. Of course, the Prophecy Twist is that the girls later realise that they were both right. (Since the game is a prequel this surprises no-one - we've already seen the main character try to start a war, twice, in the latter timeline.)
- Baldur's Gate II: Throne of Bhaal reveals that the prophecy about the Bhaalspawn bringing great destruction was actually an either-or condition: Either the Player Character will succeed, or the destruction will take place. (That is to say, even more destruction. Apparently the prophet specified some high level of destruction that would be even worse than what did happen in the games and potentially could happen because of what the Player Character could do after them.)
- Legacy of Kain: Raziel sees murals depicting two champions that will battle each other to decide the fate of Nosgoth, but the victory is undetermined as the murals show both champions slaying the other. Then in a serious Prophecy Twist, we find out Raziel is both champions at once. He ultimately allows himself to die because this is the only way he can "win," effectively meaning both outcomes of the prophecy are fulfilled - because the two champions are the same person, they both win, and they both lose.
- In Brütal Legend, the prophecy foretelling Eddie's arrival from the Modern World to the Age of Metal says that he will either destroy the world or deliver the humanity from the demons' evil. It is an early foreshadowing of the fact that he is half-human, half-demon.
- Actually, the dialogue between the characters when they are discussing the prophecy shows that there is disagreement about the translation, making this an Either "World Domination", or Something About Bananas kind of thing.
- In Vindictus, the main plot is that the goddess will appear when all the fomors are dead. It turns out that the fomors have their own prophesy with a similar outcome. By the end of Chapter 10, they both start coming true.
- At the start of Toonstruck's disk 2, Drew is locked up in Count Nefarious's castle. Ms. Fortune foretells that Drew will never escape unless a lifeless knight walks (Drew uses a magnet to move a suit of armor onto some switches that open the way to the armory), a bird rises in flames (Drew uses a dumbwaiter to serve some gator guards a turkey stuffed with dynamite), and she herself obeys his command (Drew uses mirrored glasses to reflect Ms. Fortune's Hypnotic Eyes back at her).
- The Order of the Stick:
"Do I get to cause the death of any of the following: Miko, Miko's stupid horse, Roy, Vaarsuvius or you?"
- Belkar asks the question from the Oracle:
- The answer is of course "yes".
- When Belkar complains that the prophecy didn't come true, the Oracle tries to convince him that he caused all of their deaths already. Belkar doesn't buy the Prophecy Twist so well and goes for the last one. Except that it turns out that the Oracle was Crazy-Prepared, engineered circumstances that resulted in the murder backfiring on Belkar through his Mark of Justice curse, and arranged for clerics to resurrect him after Belkar left.
- Historical example: King Croesus of Lydia asked the Oracle of Delphi what the result would be if he took his troops across the Halys River and attacked the Persians. Her answer was, "If you do, a great empire will be destroyed." The seer didn't specify which great empire. In the end, it was Croesus' kingdom, not Persia, that was destroyed, but the seer would have been "right" either way—but note that there was no way the seer could have known that Lydia or Persia would be utterly crushed (rather than a stalemate or minor gains for one side or another). That makes this a classic example of the trope, eliminating all possible middle ground. According to Herodotus, after Croesus was defeated he asked the Oracle why they were so ungrateful and was told he should have then asked them to specify which Empire would be destroyed.
- Prince Siddharta Gautama was foretold at birth to be either a great king or a great sage. His father, preferring the former, tried to shelter him from the world's pain and sorrow. When he did catch a glimpse, he ran away to meditate and became Buddha.
- A basic trick for mentalists and phony psychics is to throw these out so fast you only notice the correct sides. Derren Brown claimed in an interview to have heard a psychic tell the person they were "reading," "You either live alone, or with other people."
- Not exactly a prophecy, but more of a prediction: Adolf Hitler supposedly was so fond of this kind of platitude ("there are two possibilities: Either x will happen, or y will") that even his secretary started japing about it ("there are two possibilities: Either there will be rain tomorrow, or there won't").