The Legend of Chekhov
When somebody tells an ancient legend, chances are it's based on actual events and will be important later.
This YKTTW is based on the TRS on All Myths Are True. All Myths Are True is to be redefined as something else to reflect its name better, and its current content is transplanted and given a new name here in this YKTTW. The Law of Conservation of Detail, which demands that taking time out from the main story to tell some other story must only be done when that side story is important to the main plot.[[hottip:*:When such a tale isn't true, it's usually being used as a metaphor for the heroes' situation or to teach them some lesson that they'll need to use later.]] The purpose in labeling something important as a myth rather than just explaining it outright is to build excitement, so that when the legend is later shown to be true, it brings a sense of wonder or discovery. It can also serve to foreshadow future events, while giving the author an excuse for giving only partial or deceptive information. Compare Prophecies Are Always Right, where it's a prediction that's virtually guaranteed to be right rather than a story from the past. Note that this trope is about the characters within a story being told a myth, which turns out to be based on actual events within the story's universe. This is not about an author using real-world myths in a story (though the myth the heroes are being told may well be borrowed from a real-world source).
Examples:Anime and Manga
- In Laputa: Castle in the sky, from the very start, Pazu believes the mythical city of Laputa exists. He's not wrong.
- Saiunkoku Monogatari begins with Shuurei telling her students the story of their country's founding, ending it by saying that according to legend, the eight immortal sages who helped the first emperor found Saiunkoku are still alive in secret among the people. This is absolutely true, and Shuurei goes on to become personally acquainted with several of them. A little later in the first arc, Shuurei begins to tell Ryuuki the story of the Rose Princess and how she married a mortal man. This story is not only true, it's the story of her parents' marriage.
- In Fullmetal Alchemist, the ancient Xingese legend of the Western Sage is about Ed and Al's father, while the Amestrian legend of the Eastern Sage is about "Father," the Big Bad of the series.
- BIONICLE: In most cases, the Matoran consider most of the Turaga's stories as mere fairy tales. But most of them wind up becoming painfully true. From giant Manas to the hellish Karzahni.
- The Stephen King novel Desperation tells the legend of why an old mine was abandoned (a trapped Chinese Laborer summoned a bad spirit). There really is a monster, though actually they just Dug Too Deep and set loose an Eldritch Abomination.
- In Harry Potter and the Chamber of Secrets, the legend of the titular Chamber, which Professor Binns tells to his History of Magic class and dismisses as a preposterous myth, turns out to be absolutely true, including the deadly guardian.
- Harry Potter and the Deathly Hallows: the 'Tale of the Three Brothers' is an exaggerated and mythified version of the truth.
- In Earthsea the myth of human-dragon hybrids trapped in human form, mentioned at the beginning of Tehanu, is proven true at the book's end and forms the basis for the plot of the next novel, The Other Wind.
- In The Eyes of Kid Midas, the teacher explains that the mountain they're camped out underneath is called the Eye of God, and some ways away down in the valley there's a tall, thin spire that's known as the Devil's Chair. According to legend, the peak of the Eye of God was the place where the world was created, and once a year, the very tip of the mountain's shadow falls exactly at the peak of the Devil's Chair. Though the teacher admits it's merely a legend (and the mountain's shadow actually never goes near Devil's Chair), Kevin climbs the mountain, and at the top he discovers a pair of sunglasses that allow him to harness the forces of creation. And lo and behold, when he puts them on, he sees the shadow move fall exactly where his teacher said it would[[hottip:*:Fridge Brilliance - The shadow moved because he's wearing the glasses and believes the legend.]].
- The Mummy spends plenty of time giving us the whole legend of the Mummy before revealing that it's all true. (Which comes as a surprise to nobody in the audience, since that's the title of the movie.)
- In The Secret of Roan Inish the grandfather tells the legend of the selkie, which is important to the climax of the film.
- Scooby-Doo plays this trope for laughs Once an Episode. Typically, something spooky is going on, but is actually engineered by someone wanting to scare people away. Half the time, it's an Invoked Trope, as the fake monster is based on an old local legend (or, occasionally, the villain makes up a story and claims it's an old legend). Once in a while, there's some evidence of actual spookiness, which the heroes may or may not see.
- Digger spends more than a few strips explaining the hyena mythology surrounding their progenitor-gods "He-Is" and "She-Is", and the "badness" that came from their interactions with the demonic Sweetgrass Voice. Naturally, it's eventually up to Digger to Set Right What Once Went Wrong.
- In pretty much all the Final Fantasy games, if you talk to any random NPC who tells you about some legend, the legend is bound to be true. Hidden magical weapons? Yup. Super-powered monsters? Yup. Maze-like hidden cities? Yup.
- In Kingdom Hearts II, there are The Seven Mysteries of Twilight Town, urban legends which invariably turn out to be for real when Roxas investigates (and serve as clues to the nature of the world he's been living in). But when Roxas's friend comes along to do the write-up, he assumes each was just a misunderstanding of something mundane.
- Bungie's Marathon series contains an interesting example. The second game has a single terminal midway through the game that references a S'pht creation myth where the god Yrro flung a chaotic being into the star that Lh'owon orbits. This terminal is never mentioned by any character for the remainder of the game. The myth then forms the entire plot of the third game, Marathon Infinity -- sure enough, the Jjaro (or Yrro) trapped an Eldritch Abomination inside the system's star. Which the Pfhor destroyed in the finale of the second game.
- In Pokémon, any myth or legend you hear about from an NPC is almost guaranteed to be a hint as to where to find a particular Legendary pokemon.
- A set of daily quests in World of Warcraft has you investigate myths about three maidens who will grant powerful swords if you do each a favor. Naturally, all three of them turn out to be true.
- In Borderlands, the person who sends you to kill Crawmerax the Invincible says that most people think he is a myth and doesn't really exist. Naturally, when you get to the designated spot, he shows up. Subverted in that the quest-giver is quite surprised that you actually managed to find and kill Crawmerax since he made the whole thing up off the top of his head just to mess with people.
- Funny subversion in Lufia: Curse of Sinistrals remake. At one point you're sent to find the legendary sword, which the legends claim to have been forged by the gods and able to cut mountains in half. Just one line after that you're informed that all of that is just legend, and the sword itself is probably not even magical, but that you should get it just to boost the morale of the people. It turns our that the myth really wasn't true... but the sword is still good enough to be useful by the time you get to it.
- In Star Wars: Knights of the Old Republic, you can learn about the creations myths of the Selkath and the Tusken Raiders. It turns out that both are true and are references to the Rakata, the creators of the Star Maps.
- In Dwarf Fortress Adventurer Mode, if someone talks to you about some dragon who razed his hometown long time ago or a forest where the dead are said to rise and stalk the living, you can be absolutely sure he's telling the unvarnished truth. The only exception to this trope are centaurs, chimeras, and griffons, who sometimes appear on engravings but don't exist in the game world... yet. What's more, the stories will be told with impeccable detail. A thousand years on, everybody in the world still remembers which particular tooth was knocked out of the mouth of a random peasant by a marauding Bronze Colossus.
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