What Could Possibly Go Wrong?

When said sarcastically, it's telegraphing a disaster. When said more seriously, it's an open invitation for the world to go to hell in a handbasket.

Say there is one critical thing that could happen that would cause a catastrophe that, left unchecked, would directly or indirectly result in disaster. But everyone in the story is assured that this critical thing will never, ever happen. Ever. The audience knows better.

If anyone ever mentions a component in a reactor that is the only thing stopping a meltdown, or a lockout chip that is the only thing stopping a megalomaniacal AI from taking sentient control, rest assured that it will either fail, be stolen, or be destroyed, and things will Go Horribly Wrong.

In the event that someone in the know tries to warn his superiors to get the situation fixed, expect them to be flat out ignored.

The Law of Conservation of Detail helps this along; the scientist isn't going to bother to mention the failsafe unless it's going to, well, you know. When is the last time you were watching a movie, and someone mentioned "if this object was damaged, there would be a catastrophe!" and the object was never mentioned again for the rest of the movie? Frequently combined with Einstein Sue, where one person in the work's universe sees the incoming problem (and works to fix it).

It's often used to drive a plot. Everything is normal and then this happens and all hell breaks loose.

A sub-trope of Million-to-One Chance. Not always related with the Stock Phrase "What could possibly go wrong?". In these cases, it's often said seriously by characters performing a "simple" task where it does indeed appear that nothing can go wrong (although the end result is similar... something does). When this trope is in effect, it's said sarcastically by the audience, or one of the more Genre Savvy characters in the story, when a very obvious danger is being foreshadowed.

See Finagle's Law, Tempting Fate, Mugging the Monster, Phlebotinum Rebel, and Failsafe Failure. Compare Gone Horribly Right.

NB: ''The trope title is being said sarcastically. Before editing, see Other Stock Phrases for the Stock Phrase, which, as described above, is different from the trope. A use of this phrase in a non-ironic manner usually falls under Tempting Fate.''

Film
"Commander #1: We've analyzed their attack, sir, and there is a danger. Should I have your ship standing by? Grand Moff Tarkin: Evacuate? In our moment of triumph? I think you overestimate their chances."
 * This trope is such a central part of the movie License to Drive, not only is the exact phrase used, not only is it used by the main character, not only is the moment he says it featured prominently in the movie's trailer... but he addresses the question directly to the audience!
 * In Star Wars:

"Eve: It's only a chest. No harm ever came from opening a chest. Rick: Yeah, and no harm ever came from reading a book. Remember how that one went?"
 * The Empire has to be sure not to let sensitive information leave the Death Star while rebels are running around on the ship. An unauthorized escape pod flies out, but no worries, there's no life forms aboard (in a galaxy filled with sentient robots), so WCPGW?
 * Opening credits to Crazy Like a Fox: "All I need is a ride. What could possibly happen?"
 * From The Mummy 1999. They find the ancient Egyptian "Book of the Dead", and Evey decides to read from it. "No harm ever came from reading a book", she says. Cue the eponymous Mummy waking up and trying to kill everybody.
 * Played through again in the sequel and lampshaded.

"Sam: So, you're sure this is safe? Flint: Don't worry. I have a dangeometer that lets us know if the food is going to overmutate. Sam: What happens if the food overmutates? Flint: I dunno. But that'll never happen."
 * The Incredibles has "We're superheroes. What could happen?"
 * Invoked in Cloudy with a Chance of Meatballs:

"Stoick: I need you to stay and look after Hiccup Gobber: Oh, perfect. And while I'm busy, Hiccup can cover the store. Molten steel, razor-sharp blades, lots of time to himself... what could possibly go wrong?"
 * Let's test a new model of robot police enforcer with live ammunition! What Could Possibly Go Wrong?? OCP never learned their lesson - they do the same again later on with the "new and improved" Robocop 2.
 * Lampshaded by the ever Genre Savvy Peter Venkman in Ghostbusters: "Why worry? Each one of us is carrying an unlicensed nuclear accelerator on his back".
 * In Zack and Miri Make a Porno, Zack uses the fateful words "What Can Go Wrong?" the night before the crew was planning to shoot the real action for their movie. Since this happens only halfway in the movie, you don't need to be a genius to know what to expect after that phrase.
 * In Megamind, the titular character is bored after he defeats his nemisis, Metroman. So he decides to create a new nemesis by giving someone else Metroman's superpowers. What Could Possibly Go Wrong? (IIRC, Minion asks this ironically. Well, instead of giving an altruistic person superpowers, he accidentally gives them to an average joe (at best). He decides to go along with the plan anyway. Then, after said average joe . Great plan.
 * In How to Train Your Dragon:


 * In Babes in Toyland (1986) one of the good guys explains that he's been collecting the evil of the world, distilling it to its essence, and sealing it into a bottle.
 * "There's over 30 cops in this building. You're perfectly safe here." Oh, how wrong you are, Detective Traxler.
 * The print ad for the 1973 movie Westworld reads "where nothing can possibly go worng" (deliberately sic).

Literature

 * Animorphs: Since improvising is a big part of their plans, this tends to happen often. Tobias even lampshades this in his own plan at one point.
 * Jurassic Park. Although in this one, the critical "thing" that could happen (the control system being hacked, among other things) isn't clearly foreshadowed. But c'mon, an island full of vicious dinosaurs run by an man who continuously insists everything is perfectly safe is just asking for trouble.
 * In the book, this is all but Ian Malcolm's sarcastic catchphrase.
 * This is the plot of the book and film Fail Safe. An accidental nuclear attack on the USSR is impossible, Mr. President.
 * And Dr. Strangelove. In fact, they sued Fail Safe because it was so similar.
 * In the novel The Amorous Umbrella the hero is trapped in a world based on the more melodramatic 1950's soap operas. By that world's natural laws, the surest way of committing suicide is to say "I've never felt better in my life".
 * In the great Indian epic Ramayana, a Rakshasa general leads his 14,000 troops against one man: Rama. His last words; "He's only one man."
 * Ravanna the Demon-King was so hard to kill because of blessings he extorted from Brahma that prevented gods and demons and such-like from killing him. He disdained to get immunities from human or animals, because they were mere food. What could they possibly do?
 * One of Spike Milligan's silly poems for kids has the King of China declare "I've never felt finer!" — and then promptly keel over and die.
 * W. D. Robert's children's mystery, entitled " what could go wrong?" the answer? Just about everything that could when you have three kids( one of whom is very accident prone) and send them off to visit their aunt- alone. oh, and don't forget the guys with guns.
 * Inverted by Ronald Weasley: "Have you ever heard of a plan where so many things could go wrong?"
 * Ironically, almost everything involved in the plan goes right.
 * In Septimus Heap,
 * Subverted in Harry Potter and The Chamber of Secrets when Ron asks "Have you ever heard of a plan where so many things could go wrong?" and while things don't go exactly according to plan, it does go mostly right.

Live Action TV
"Harrison: Hello? Harry: Harrison, I need your help. Harrison: Dad, you keep forgetting. I'm a lawyer. You're the detective! Harry: Aw, come on son. All I need is a ride. What could possibly happen?"
 * The premise of every episode of the 1984-86 US TV series Crazy Like a Fox. The series starred Jack Warden as Harry Fox, a free-spirited private detective who lived by his wits and John Rubinstein as his high-strung attorney son Harrison who unwillingly and frequently found himself dragged into his father's cases. The show's opening would always feature Harry and Harrison talking on the phone in their offices like this:

"Richard: Oh, how I've missed the pang of dread every time you say the words "How hard can it be?""
 * Jeremy Clarkson saying,"How hard can it be?" on Top Gear, often always uttered before they show a segment where the presenters have to work on cars.
 * Lampshaded once, after the series came off hiatus:

"Lorne: A memory spell — provided by one of my clients — that is guaranteed to bring our Cordy back to the way she was. Angel: Guaranteed? Lorne: No pain, no side-effects. I'm telling you, swingers, there's no way this can fail. Cut to Lorne, narrating Lorne: So, I'm an idiot. What are you — perfect?"
 * And lampshaded pretty much every time he says it by Hamster and May ever since.
 * In the Angel episode "Spin the Bottle," Lorne introduces the Phlebotinum:

"Dawn: Come on, songs, dancing around... What's gonna be wrong with that?"
 * A fine example in the Buffy the Vampire Slayer episode Once More With Feeling:

"Xander: As long as nothing really bad happens between now and then, you'll be fine. Buffy: Are you crazy? What did you say that for? Now something bad is gonna happen! Xander: Whaddaya mean? Nothing's gonna happen. Willow: Not until some dummy says, 'as long as nothing bad happens!' Buffy: It's the ultimate jinx! Willow: What were you thinking? Or were you even thinking at all?"
 * Snap cut to the demon Sweet looking at one of the dancers.
 * Lampshaded in an earlier episode:

"Toby: It's not going to be a big deal. Sam: Isn't that what we usually say right before something becomes a big deal?"
 * Lampshaded on The West Wing:

"Ida: We’ve come this far, there's no turning back. The Doctor: Oh, did you have to? 'No turning back'? That's almost as bad as "Nothing could possibly go wrong" or "This is gonna be the best Christmas Walford's ever had.""
 * Doctor Who:
 * "The Satan Pit":

""Right, perfect, look at that; what could possibly go wrong? (bit falls off the console with a crash) That's fine; that always happens.""
 * The Doctor later lets loose with a "WCPGW" at the start of the episode "Midnight"; his tone suggests he wants something to go wrong. And it does, and he's very sorry by the end of the episode.
 * In "The Doctor's Wife" he's knocked together an improvised TARDIS from spare parts.

"ROMANA: Don't you think that's a bit dangerous? DOCTOR: No, I don't. What could possibly go (Lurch. The Doctor falls.) DOCTOR: Ow! Wrong. You know, I've simply got to stop saying that. Every single time I say what could possibly go wrong, something goes (Lurch.)"
 * The Horns of Nimon it gets lampshaded:

""NBC asking the host of Late Night to come to Los Angeles to host a different show, what could possibly go wrong?" Camera cuts to Conan O'Brien in the audience."
 * The predictable Sitcom variety is parodied on That Mitchell and Webb Look, in the "Get Me Hennimore" sketches. The boss gives his The Ditz employee a truly preposterous set of tasks to do, with maximum scope for confusion, embarrassment and general disarray, and tops it off by wondering aloud how his instructions could possibly be misconstrued; Gilligan Cut to the smoking aftermath. "HenniMOOOORE!"
 * In the Star Trek: Deep Space Nine episode "Our Man Bashir", Garak ends the teaser by saying "What could possibly go wrong?" Well, it's probably a Lampshade Hanging for the frequency of a Holodeck Malfunction in a fairly trope-heavy episode. The holodeck later malfunctions and they're stuck in a James Bond simulation for the entire episode.
 * In Honey I Shrunk the Kids, when Wayne says it, the dog he's talking to leaves the room.
 * Jimmy Fallon used this in a joke while hosting the 2010 Primetime Emmys:


 * On Doogie Howser, Doogies best friend is trying to convince him to go with him to check out an car after work. He warns Doogie not to try to get out of it with some gallbladder emergency. Doogie assures him it's an Wednesday and nothing ever happens on an Wednesday. Then he walks away from the TV where the news announcer says "The Verdict in the Rodney King Trial has just come in," and the Intro begins.
 * Said word for word by Dean in the season 7 finale of Supernatural.

Newspaper Comics
"Calvin: We'll move it 10 feet. What could possibly go wrong?! Hobbes: Whenever you ask that, my tail gets all bushy."
 * Calvin and Hobbes, about Calvin's plan to push the car out of the garage so they can use it as a clubhouse:


 * And with good reason. The car winds up rolling out of the driveway, down the road, and into a ditch.

Newspapers

 * Oh, boy! It's a title of a oddball story from about Tour De Paris for prisoners. If you don't believe me--check this out.

Video Games
"Ginko: I've had just about enough! The scenery here never changes!! Enough, enough, enough! Eikichi: Quit whining!! How about this idea? Would you be happier if there had been a waterfall or somethin'? Huh!? Maya: Shh! Be quiet... That noise... Could it be!? (Cue Waterfall up ahead.)"
 * The Trope Namer was Bubsy ' s catch phrase. Cranked Up to Eleven in the Animated Adaptation.
 * It's also the name of the pilot episode, appropriately enough.
 * Dead Space; breaking down entire planets for their mineral resources, hmm, not too bad, already pretty dangerous, but it's mundane dangerous, what are the odds of finding some VERY unwanted cargo when you start mining the place?
 * Given how much Hollywood Biology you need to justify a species surviving having its planet torn apart...About a Million-to-One Chance.
 * Dr. Muto says this before turning on his everlasting power source, which five seconds after being turned on blows up the entire planet, except for his house.
 * Half-Life. Black Mesa. "The possibility of a Resonance Cascade scenario is extremely unlikely". Guess what happens.
 * Yeah, well, that's why we have insurance.
 * Lampshaded in Dragon Age 2, in which Varric observes that 'I don't like this' is right up there with 'What could possibly go wrong?' when it comes to Tempting Fate.
 * Homeworld: Cataclysm. Let's open a million years old alien pod after having tucked ourselves in the furthest corner of the galaxy, where no one can come to our aid in case something goes wrong!
 * Persona 2: Innocent Sin, when the party is at Xibalba, where it's revealed later on that : (Fan Translation version.)


 * Bioshock. Andrew Ryan one day wakes up and goes, "I know, I'll create a submerged city with 1940 technology where the law of the jungle is the only real rule, and everyone is free to do whatever they wish as long as it profits them. What Could Possibly Go Wrong?" When the player stumbles upon it, the question that comes to mind is "What didn't?"
 * In Seven Days A Sceptic practically everything on the ship is built on the assumption that nothing will go wrong (whereas in Real Life the opposite holds true). Examples include escape pods that need to be fueled up for hours before use and the captain's suite emergency unlock, which is installed on the inside. The ship's scanners can also track the number of living beings on board but not their locations, the power source is mounted in a huge shaft with no railings, there's a glass-domed observation deck with no apparent protections against micrometeorites (or radiation, for that matter) and the prison cell uses a force field instead of metal bars that won't vanish in case of power failure. No wonder the engineer spent most of his time hiding in the dining area and making the counselor fix things for him - he must've had a breakdown on the first day and been in denial since.
 * In Mass Effect, the Reapers play the Batman Gambit by letting species of the galaxy find their technology littered across several star systems just so they can advance to a desirable state, ripe for a galactic harvesting. Really, how can this backfire?
 * In Star Wars Jedi Knight: Jedi Academy Jaden Korr is tasked by Kyle Katarn to destroy illegal weapon chaches in the planet Ord Mantell. He says: "This should be easy. Just plant some charges, watch the fireworks and come home. What can go wrong?" Well, one notorius clone bounty hunter might just appear.
 * Fear Effect. Hana says this at the end of Retro Helix. It shows the King of Hell surrounded by fire and laughing hysterically. Those who have played the first game should know exactly what could go wrong.
 * The haiku that describes the Black Cat familiar in Kingdom of Loathing is "What a cute kitty!/What could possibly go wrong,/with her at your side?" It is one of the two most actively harmful familiars in the game, reducing experience gains, depleting MP, destroying randomly dropped items, and occasionally preventing the use of skills and items in combat.
 * In World of Warcraft, an Alliance quest in Vashj'ir has you go kill some demonic octopi that are mind-controlling some of the gilblins and take their heads. The NPC who gives you the quest then suggests you put one of them on your own head, quoting this trope. It turns out the demonic octopus wasn't quite dead...

Web Comics
"Red Mage: And now that I've described the plan in full, nothing can possibly go wrong."
 * This strip of DM of the Rings is an exemplary usage.
 * This strip of Anders Loves Maria.
 * This strip of the Web Comic Kevin and Kell.
 * Eight Bit Theater seems like it's on the brink of invoking this trope:

"Sam Starfall: Hey, even I don't say that out loud."
 * There's also Episode 703: What Could Go Wrong?, which indulges in some heavy Tempting Fate.
 * Frequently invoked and lampshaded in Narbonic, particularly here (the bottom comic).
 * The bunny - Oh God the Bunny.
 * In El Goonish Shive, one strip is titled "Surely Nothing Bad Can Come from This"
 * Freefall Let's not forget #1654. Varroa Jacobsoni says it word for word.

"Guy: Aw, c'mon, Beth! I know it's a bit creepy, but what's the worst that can happen?
 * this strip of The Whiteboard.
 * Lou Ghastly, as a humorous horror-style work, had this on the very first page - with a pair who stopped next to the cemetery to make out in a car at that.

Hellish thing: Bleauuugh!! Souls! I need soulsgh!!"

"Vexxarr: I would have thought that by now you'd know better than to ask a question like that out loud... Minionbot: ...and ruin the fun?"
 * Vexxarr has this said... on purpose.

Web Original

 * The two Michaels in Doomsday Arcade often, in early episodes, come up with ideas, complete with Imagine Spot, and say "I see no other possible outcome". Naturally, none of these plans work at all, which leads to their eventual observation that they should really stop saying that.
 * Whateley Universe example: Phase said it in an early chapter of the currently serialized Ayla and the Birthday Brawl. Readers know what Phase doesn't: an internationally feared supervillains with a major grudge against Team Kimba was told about Ayla's planned party, and has a week to plot something really nasty.
 * Phase probably knows just what's going to go wrong, seeing as it's happened on both of his previous trips... and has had everyone else telling him exactly just that for a few episodes. In consideration of this, he's managed to invite - in a relatively roundabout way - enough students with oddball and incredible powers, alongside an ex-Admiral with a nanite swarm guiding her every move. Obviously, this means that he's prepared for nearly every eventuality.
 * Deceased Crab likes this trope a lot as he often says "What's the worst thing that could happen? Please don't answer that." Since he has played every game that he LPs before, things often do go wrong afterwards.

Western Animation

 * Subverted/parodied on The Fairly Odd Parents. When Timmy gets his daily life turned into a reality TV show, Executive Meddling forces him to adopt the trope title as his Catch Phrase. Then, when Timmy invokes the phrase while referring to his mom's cooking, she thinks Timmy is insulting her.
 * Most of the time it's played straight, however. That became his catch phrase because he actually does say the trope title often. It's almost a Once Per Episode thing for Timmy.
 * Its used so often that when things inevitably go bad when Timmy wishes to be in an old cartoon, Cosmo complains that no one had a chance to say what could possibly go wrong yet.
 * Said literally by Genie in Aladdin and the King of Thieves, just before the titular King of Thieves reveals his plan to crash and rob Aladdin's and Jasmine's wedding.
 * This is literally the title of the pilot (and only) episode of the cartoon based on Bubsy. It's also his catchphrase during said show.
 * This becomes Spanky Ham's catchphrase on Drawn Together.
 * In the South Park episode "Free Hat", the boys form a club to save movies from their directors. When they get an appearance on Nightline, Cartman says he will speak because he's the spokesman. When Kyle tells him not to screw up, he says the trope. Besides immediately relinquishing the job to Tweek when Ted Koppel asks why they advocate toddler murder (It Makes Sense in Context), the appearance also gives Steven Spielberg the idea to remake Raiders of the Lost Ark.
 * esternAnimation/RegularShow has quite a few examples, especially Appreciation Day, which has a manager's book in which only the truth can be written. Rigby and Mordecai write tall tales in it.
 * Cera says this in the second The Land Before Time movie.
 * In the Duckman Episode "Clear and Presidente Danger", Duckman begins wondering out-loud about becoming the new leader of the third-world country Porto Guano and ends with "What Could Possibly go Wrong?" Cornfed Breaks the Fourth Wall to say to the audience "For a complete list, please send $12 to Journal Graphics, Washington, DC, 20300."
 * The basis of virtually every mission the Vulture Squadron encounters on Dastardly and Muttley in Their Flying Machines.
 * One name: Wile E. Coyote.
 * The Powerpuff Girls Movie: Jojo assures the girls that Townsville will love them after they help him with his plan. Suuuuuure, they will.
 * Ben 10: Omniverse has an episode with Ben in an alternate universe. His counterpart says the phrase.  Ben, being Genre Savvy, expects it to be bad, but nothing happens because they're in another universe and apparently, in that universe the phrase isn't associated with bad things happening.

Real Life
"At this point you should be hearing ominous music and people ignoring a lone researcher's desperate warnings."
 * Let's simulate a power blackout in our nuclear power plant to field-test the new emergency cooling system we installed. Oh, but wait, that's not enough - we also need to disable all the safety precautions, and then end the experiment with an emergency measure that was never meant to be used routinely. What could possibly go wrong?
 * The 5 Scientific Experiments Most Likely to End the World, courtesy Cracked, invokes the trope by name.
 * This more recent article has this for #5 among others, where a life form grows instead of dying when subjected to extreme gravity:


 * A highly-contagious pathogen being tested in a lab in tornado alley. Slashdot link (note the tag).
 * We want the ship to look good on the papers, so punch it and never you mind the icebergs. After all we've got a fancy new doublebottom-hull, we're able to stay afloat with four compartments flooded instead of the usual two, and we have four more lifeboats that is legally required! What could possibly go wrong?
 * The perfectly safe Hindenburg.
 * While it seemed safe enough at the time, in hindsight, flying around in a balloon filled with hydrogen is pretty dangerous. To quote Wikipedia, "nowadays helium is preferred because of its lack of flammability." No kidding.
 * Also, while it wasn't precisely painted with rocket fuel, the metallic paint on the thing didn't help in the least.
 * The guaranteed big seller Ford Edsel.
 * The New Coke. Let's radically change the recipe for our flagship soft drink, keep the same name, and take the old one off the shelves. Now, according to The Other Wiki, Coke did do their best to prepare for it, and it actually was well-liked. The real problem was a subtler one of a Vocal Minority gradually convincing people it was bad. If true, that speaks volumes.
 * This almost gets into Idiot Hero territory, since the crazed backlash against New Coke put Coke Classic back on top of the sales charts. Some people think that was their plan all along. Another, less rouletty theory is that they did this to switch from sugar to far cheaper and far less healthy high fructose corn syrup; a change they retained, and still do, with Coca Cola Classic.
 * More recently, Coca-Cola's done it again: Let's release a holiday version of Coke Classic in white cans (the color of Diet Coke cans) and hope nobody gets confused. It didn't go over well, and Coca-Cola has since released the holiday version in red.
 * Perhaps A slightly more subdued example, Coke switched from an easy-to-grip ridged cap to one that is themed as a bottle cap, but completely smooth. Cute, but wrong. They have since adopted some sort of hybrid
 * History Channel's Modern Marvels series does a sub series titled "Engineering Disasters" every now and again. Every one of them seems to invoke What Could Possibly Go Wrong? at least once per episode. They've produced 21 hour long episodes and still haven't covered everything. National Geographic Channel has Seconds From Disaster which is the same thing.
 * Subverted by an experimental reactor in Switzerland. While the guy in charge had a "What Could Possibly Go Wrong?" attitude, the engineers considered this phrase a serious question, and built the reactor in a cave just in case they got an answer. Naturally, they got an answer, and sealed up the cave.
 * This article about a possible war against Iran is Exactly What It Says on the Tin.
 * The "Big Dig" in Boston. "Let's replace the unsightly and congested Central Artery expressway with an underground tunnel! Then, let's reclaim the land where the old highway used to be, building parks, gentrifying the slums that developed around the highways, and de-congesting surface traffic! What Could Possibly Go Wrong??" Two decades, $15 billion, several lawsuits and four deaths later...
 * The Rolling Stones hire Hells Angels to work security and pay them in beer. At least one audience member wound up dead.