When first we practice to deceive!"
A lie or deception that takes on a life of its own, spiraling out of the control of the ones who started it and often mutating in the process. What distinguishes a Snowball Lie from a "Fawlty Towers" Plot lie is that it attracts other characters to keep it alive and expand it, either by explicitly furthering the deception for their own purposes or by sincerely buying into it and carrying it on in the honest belief that it is real — or to avoid being embarrassed by their "ignorance" or "inexperience".
Usually a Snowball Lie will eventually grow to a point where it will collapse, either under the weight of its internal contradictions or after some insightful person Pulls The Thread on it. Sometimes, though, a perfect Snowball Lie will show no signs of ever stopping, and its creators will find themselves forced to kill it — with varying degrees of success, and varying degrees of repercussions to themselves. In particularly ironic situations, the Snowball Lie can become an unstoppable juggernaut that displaces the truth and becomes a new "truth" in its own right.
- In Noob, Master Zen framing Gaea for having done something that greatly hurt the Empire (her own faction) and gave an advantage to the Coalition became this. The event in question caused the foundation of the Guild of Gaea Admirers, who are convinced Gaea is a Double Agent, in the Coalition. While not a Double Agent, Gaea is a Manipulative Bitch and went Sure, Let's Go with That on the story because it gave her nice set of minions. The minions in question end up protecting Gaea from being hurt by the character who framed her in the first place. Master Zen, having figured out what happened, tried to tell the minions that Gaea had lied to them and he was the one who actually committed the act for which they praise her, only to get a Cassandra Truth moment.
- The plot of Dear Evan Hansen revolves around the titular character becoming entangled in a web of lies as he convinces everyone that he was best friends with Connor Murphy, who commited suicide near the beginning of the show. Shortly after Connors suicide, the Murphys find the note Connor had with him, which was Evans letter he wrote to himself for therapy, and assume Evan and Connor were friends. Evan, too nervous to refute, agrees, and soon, he teams up with Jared to create fake emails to prove that they were friends. As the story progresses, Evan starts The Connor Project, which is devoted to honoring Connors memory; forms a close bond with the Murphys; and gets close to his crush, Zoe (who was Connors little sister). As Evan falls deeper and deeper into his lie, he feels trapped, and eventually confesses that he was lying all along in the heart-wrenching number "Words Fail".
- The plot of A Funny Thing Happened on the Way to the Forum is essentially centered around one of Pseudolus the slave's schemes, which gets bigger and more convoluted as the show goes on. First, in order to get Philia (A courtesan) from Marcus Lycus for his master Hero, Pseudolus claims that Philia is a plague carrier, tricking Lycus into fobbing her off onto Pseudolus and Hero. Then, to keep Hero's father Senex from finding out, Pseudolus claims Philia is a maid, and convinces Senex to take a bath in the house of Erronius; to keep Erronius away, Pseudolus pretends to be a soothsayer and has the befuddled old man run around Rome to rid himself of a curse. Then Miles Gloriosus, the conquerer who actually bought Philia, arrives and things just get more outrageous from there.
- Neil Simon's Rumors features a lie that gets confused and destroyed not once, not twice, but three times, first when the main couple are letting the other couples in and need to explain what Charlie and Myra are doing, second when the police officers first show up, and third, in a dramatic monologue about what allegedly really happened it actually did to get the cops off their back for the last time.
- The Norwegian comedy Rett i Lomma (Right in The Pocket, referring to easily obtained money) is built on this trope. It is about a man who lost his job, and the money he gets from renting out apartments on the side in his house isn't enough to keep it going. The very same day, however, he gets a welfare check from the bank to "Mr. Thomason", who had recently moved to Canada. He decided to use it for himself instead of forwarding it. Then he finds out that by inventing a few fake occupants with various family and illnesses, the government would keep sending him money to support them. Cue the actual start of the play, where he decides that it has gone on for long enough and that he will have to "kill them off". Unfortunately, this only makes things worse because of the payout for funeral, etc. And then, an inspector knocks on the door and wants to look through all his paperwork for the last two years. It ends up with him having to not only play the part of Thomason, but also having to drag in his only real occupant as he walks in on a conversation and starts asking questions. Then an agent from the funeral service and his assistant arrives, as well as his uncle, his friend's girlfriend and his own wife. The network of different lies and explanations soon expand and start conflicting, and the two friends also have to make up lies while separate from each other. Therefore you get such situations as the apparently deaf Normann answering the phone, the wife having to be "accidentally" locked into their bedroom because she became too annoying, and the inspector being served tea and wine until he's drunk. It finally collapses upon them as the inspector's much more level-headed boss arrives, and the main character is given a new job as inspector because he "knows every trick in the book". While hard to follow, at least the convoluted thing was damned funny and had a happy ending.
- This Episode of Amazing Super Powers certainly qualifies.
- I Fell in Love, so I Tried Livestreaming: When Souta crossdresses in an attempt to set a Honey Trap for Yuu, Vina suggests that Sora and Yuu act as a fake couple to ward him off. This backfires because of the dorm's no romance rule and because of Sora's double life as a net idol. Vina then tries to cover this up with another lie by claiming that he confessed to Sora, thus necessitating that she forms a fake relationship with Yuu, but Yuu senses that this lie will get out of hand and properly explains the situation to the whole dorm.
- In Sword Art Online Abridged:
- This is how Kirito and Asuna's marriage plays out over Episode 10. To fill an awkward post-coital silence, Kirito blurts out a proposal (while his brain screams at him), and Asuna is so surprised she accepts (while her brain screams at her). Their guild commander finds out about it and sends them off on a "honeymoon" so they won't screw up a key diplomatic meeting, and doesn't notice how they're both freaking out over the idea. Then Yui shows up and is adopted by Asuna in hopes that by upping the ante Kirito will be the one to "blink" first and break off the engagement, but he realizes what she's doing and plays along. And eventually the two of them are hysterically offering to buy an orphanage and adopt all the children in it.
- The big reveal at the end of Episode 11 is that the entire "death game" scenario is one of these too. Sword Art Online's creator accidentally created a glitch that killed players when their characters died, but was losing his mind due to sleep deprivation after rushing to finish the game, so he decided to "double, triple and quadruple down" under the logic that it would be better to appear evil and competent than lethally incompetent. He locked the players in the game to serve as hostages while he tried to find a better solution, failed, and after two thousand players died in just the first month, was forced to take action as a guild leader to try to get them through the game. But his mental state deteriorated even further when he realized just how stupid the players were, so after two years he's forced to admit that he's lost control over the situation and just wants it all to end.
- The "Cottingley fairies" case.
- The "Crop Circles" hoax was a Snowball Lie that grew so big that even when its authors (two old men from England) tried to kill it, ufologists and other enthusiasts refused to believe them. Of course, they were also imitated by dozens of copycats, hence the excuse that "Well, you might have done some of them, but what about these ones?" The same goes for things like Bigfoot and the Loch Ness Monster. Just like the crop circles, when people came forward to announce that they were involved in the hoaxing, believers accused them of lying to cover up the real creatures.
- There's also H.L. Mencken's "bathtub hoax", where his bogus history of the bathtub, "A Neglected Anniversary", was believed as truth for decades after it was published in 1917.
- The Protocols of the Elders of Zion, a fraudulent anti-Semitic manifesto about a worldwide Jewish conspiracy. It was first used to scapegoat Jews for the monarchists' defeat in the Russo-Japanese war and the Russian Revolution, was infamously used by Adolf Hitler according to some historians as his justification for his campaign of genocide during World War II, and is still believed to be real by many people even today.
- You know that one person in your life who insists on topping every story brought up with something even more outlandish that happened to her? If your car just got towed, hers rolled off a cliff. If your sister just had twins, her cousin just had triplets, plus another set of triplets two years earlier. And let's not get started on the stories she comes up with when you mention that your back hurts (her various conditions include sickle-cell anemia, scoliosis, ADD, chimera-twin syndrome, and the inability to go out in full sun). Miss Manners says that when you have to deal with someone like this, the most useful thing to do is to play along, earnestly asking for details that may eventually show her story to be a Snowball Lie. Even if you don't believe her, at least now you're both entertained.
- Perhaps one of the most tragic and best-known cases of this were the Salem witch trials in colonial America. The witch hunt was started by three girls who claimed to be possessed by demons, and who went into "fits" because of it. When they later confessed to lying about it, however, the trend was so huge and so many people were caught up in such a panicky situation that the people simply refused to believe them, choosing instead to believe that it was the demons within them who were making them "confess" their lies.
- In a similar fashion, the so called "Gävle Boy", Johan Johansson Grijs, who was one of the most infamous children involved in the Swedish witch trials. After he had accused his own mother of witchcraft and gotten her executed in his hometown Gävle, he was sent to relatives in Stockholm, where he continued to accuse people and got other children to do the same. This went on for quite some time, until someone realised that he knew a bit too much about witchcraft for being a victim, and he himself was sentenced to death. He panicked and confessed to lying, but was executed for that instead.
- The claim that Abner Doubleday invented baseball in Cooperstown, New York in 1839. Doubleday, a military hero, never claimed to have invented baseball, and there's no evidence he'd ever even visited Cooperstown. In fact, the first printed reference to baseball in America was in 1791. In 1908, 15 years after Doubleday died, a commission whose open aim was to prove that baseball was strictly American in origin announced their findings that Doubleday was the inventor. This claim was based the testimony of just one person, an elderly mentally ill man, who would have have been a young boy in 1839. The report was forgotten until the 1930s. Then Major League Baseball kicked of a massive campaign to celebrate the supposed centennial of baseball in 1939, culminating in the opening of the Baseball Hall of Fame in Cooperstown.
- Various child abuse scandals, especially those with supposed Satanic cult connections and multiple alleged perpetrators, result from this: one suspicious parent, teacher, or social worker questions a child (who may or may not be an actual abuse victim) and soon worried parents are questioning their kids and the number of "victims" and "abusers" starts expanding dramatically.
- Your typical "moral panic" starts out as a joke among teenagers on the school bus or in the locker room, an adult takes the joke as irrefutable fact, and suddenly talk shows are hosting parents crusading against kitschy fashion accessories and soda can pull tabs. Some moral panics make their way onto Forensic Dramas, like the "rainbow party" panic that leapt from The Oprah Winfrey Show to CSI. Then there's the porn industry, which is always eager to make a profit from anything scandalous and may even attempt to play up parents' fears while advertising material based on moral panics.
- French con-man Frédéric Bourdin claims that his infamous attempt to assume the identity of Nicholas Barclay, a missing American teen, was an example. Bourdin had cobbled together a living by repeatedly passing himself off as a runaway teen and getting free room and board from government agencies around Europe. However, when he tried his con to Spain, the authorities insisted that he provide verifiable identification for who he was. Fearing he would be arrested if he did not provide an identity, Bourdin acquired Nicholas Barclay's information and claimed to be him. When the authorities began moving forward with reuniting him with his "family," Bourdin simply went along with it.
- And to make this story even weirder, it's possible that this collided with another Snowball Lie by the part of the Barclay family: Bourdin neither looked nor acted like Nicholas (which Bourdin excused with a ludicrous explanation of being kidnapped and experimented on by a ring of child molesters) and yet the Barclays insisted that he was Nicholas even as an independent investigator figured out the truth and pointed out the inconsistencies. When he finally confessed, Bourdin claimed that based on the insistence as well as the fact that Nicholas' mother and half-brother treated him oddly and coldly, they had actually murdered Nicholas, pretended he had gone missing, and thus kept up the charade with Bourdin once he showed up. The investigator actually agrees with Bourdin but the case has gone cold after Nicholas' half brother suddenly killed himself.