"Mentsch tracht, Gott lacht." ("Man plans, God laughs.")
— A Yiddish proverb
Ah, nothing denotes how Crazy-PreparedThe Chessmaster is like the good old Gambit Pileup. Truly, there is nothing these twelfth-level omni-geniuses have not contemplated in their equations and planned for with contingencies B through Z42t.
Then something, or someone, happens. Not just something that the Chessmaster didn't know about, but something that he didn't know he didn't know. In fact, there was no way he could have known that he didn't know this. Thus the brilliant plan goes to pieces, with a deadpan "I Didn't See That Coming" once the dust settles. Less Stoic fellows may go Oh, Crap or into Villainous Breakdown, though usually it's a Spanner in the Works that causes that reaction.
Problems tend to come in five varieties, of which varieties 3, 4, and 5 qualify for this trope:
Known Knowns: There are the known dangers, these you deal with directly: My opponent has access to laser blasters — I need Deflector Shields before I attack.
Known Unknowns: These are the things strategists know they don't know, but they can prepare for the different possible outcomes: The enemy has his forces deployed elsewhere when you are Storming the Castle, so you need one plan for what to do if these forces do not return in time (to take full advantage), and you need another plan for what to do if these forces do return in time (to avoid getting trapped in a pincer). Someone who is especially good at this kind is probably Crazy-Prepared.
Unknown Unknowns: Then there are the unknown unknowns, or even unknowable unknowns. These cannot be prepared for, planned for, or in any way anticipated. They are the bane of all well laid plans. This can often be a Genre Shift, for example, and the character was in the dark because of the masquerade. The mage being surprised by the space alien, for instance, or The Mafianot expectingPsychic Powers. Acts of God and Outside Context Villains tend to fit in here, unless characters are aware that they are a Cosmic Plaything, and even then it's hard to know what you don't know, except that you don't know anything.
The first is a False Assumption: he had assumed that the other masters would have acted as mages and, in an attack on his stronghold in the higher roofs of the Hyatt Hotel, would have had to deal with his enormous preparations. Here comes Kiritsugu, who just blows upthe whole hotelwith explosives. Kayneth survives, but the explosion and the demolition destroy all of his defensive measures and almost all of his Mystic Codes;
In revenge for Kiritsugu's attack, Kayneth attacks him in the Einzbern Castle and runs head first in another False Assumption and an Unknown Unknown. The False Assumption is that his last Mystic Code could easily defend him from mundane weapons, but while Volumen Hydragyum can easily repel the pellets from Claymore Mines and the fire of a Calico M950 it has to concentrate to defend from the point blank fire of a Thompson Contender chambered for .30-06 rounds, and he survived with a wound only because the Contender is single shot. The Unknown Unknown happens when Kiritsugu returns with the Contender: this time Kayneth concentrate his defense and reinforces it with prana, not knowing it was exactly what Kiritsugu needed for hisOrigin bullet to completely and irreversibly destroy Kayneth's ability to use magic, nearly killing him through the sheer pain and leaving him paraplegic as a side effect;
After surviving Kiritsugu thanks to Lancer, Kayneth runs into an Unknown Known: his fiancee Sola-Ui is madlyinlove with Lancer, and tortures poor Kayneth to get the Command Seals. He could have avoided the torture and having to give up the Seals by calling Lancer with a Command Seal, but his False Assumption that Lancer was willing to betray him prevented him from it. These would both fall under Unknown Known errors if he'd bothered to read up on the myths regarding his own servant, Diarmuid Ua Duibhne. Sola-Ui falls prey to Lancer's cursed beauty mark, as his future queen did in the myth. And she forced him to betray his lord with magic.
After much meddling, Kayneth is seemingly having some luck. Sure, he had to force Lancer to suicide and give up any role in the War, but he managed to have Kiritsugu force himself to not harm him first... And False Assumption and Unknown Unknown hit again in the form of Maya Hisau, Kiritsugu's assistant, who, before Kiritsugu signed the magical contract, had been ordered to kill Kayneth and Sola-Ui as soon as Lancer killed himself. To rub salt into the wound, Kayneth is just mortally and painfully wounded, and when he begs Kiritsugu to finish him he's told that he can't either finish him or tell Maya or Saber to do it due the oath (thankfully Saber has some pity and kills him on her own).
Running into one of these is how Light of Death Note finally lost.
Specifically a Type 4. It occurred to him his plan might have been anticipated, but underestimated his opponent's capacity to do so.
Actually Type 3: Shidou was a greater Spanner in the Works than anyone else, and there was no way Light could have foresaw the damage he did.
Hell, come to think of it, it's what did L in, as well. Being the world's greatest detective can only take you so far if your nemesis has a god on his side.
Kyon of Haruhi Suzumiya gets a note asking him to meet in the classroom after school. He's pretty sure it isn't any of the SOS members, but he thinks a little about how he'll respond to each of them, if it is one of them after all. He knows that he does not know who it is. However, it was not possible for him to know that Ryoko Asakura was actually an alien waiting there to murder him. He got hit with Didn't See That Coming, and it was not fun. At least, not for him — for the audience, it was freaking awesome.
Quattro, the resident Smug Snake from Magical Girl Lyrical Nanoha StrikerS encounters a tiny flaw that completely undoes her whole plan when she overlooks a few critical facts. First, that Nanoha is a mage that specializes in blowing stuff up. Second, that Nanoha is using a special booster system that makes her capable of blowing up even more stuff. And finally, that Nanoha was using area search magic to look for the cyborg the entire time she was fighting against her adopted daughter, per Quattro's plans. On top of all that, somehow Quattro tends to overlook an even more critical fact regarding the way Nanoha treats her friends and loved ones. While being ignorant of the third was a reasonable possibility, there is absolutely no excuse for the first two, not to mention Nanoha's tendency to befriend people. The end result... Oh, Crap!
Of course, Quattro did see it coming in the end. She was just too late to do anything about it.
On a wider scale, Jail and the cyborgs got blindsided completely by Section 6' available firepower, due to careful management of their Power Limiters hiding what they were really capable of.
Alucard in Hellsing is finally finished off when the Major gets him to weaken himself by unleashing his familiars, become injured by fighting a newly vampirised Walter, then try to restore himself by reabsorbing his familiars and all of the blood in the devastated London. The snag for Alucard comes when the Major has Schrodinger commit suicide and be absorbed by Alucard; Schrodinger's nature means that he ceases to exist if he cannot identify himself. Being absorbed by Alucard and melded with the souls of his familiars makes him unable to identify himself, causing him to cease to exist, and taking Alucard with him.
In One Piece, the World Government captured Ace and imprisoned him, prompting Luffy to break in to get him out. Normally, one pirate single-handedly invading their fortress jail to break someone out under maximum security would be an easy matter to deal with. Unfortunately Luffy ultimately set all their prisoners free, recruited as many as he could into fighting the World Government with the surprise aid of Buggy the Clown, Mr. 3, Mr. 2 Bon Kurei, and two ex-members of the Seven Warlords of the Sea. To top it off, a current Warlord, Blackbeard, turned on them for unknown reasons while everyone else was preparing for all-out war with Whitebeard. And wouldn't you just know it, numerous prisoners that Luffy recruited have the exact powers needed for the group to succeed. Unfortunately, things don't go as planned. Things don't go as planned at all.
A better example is when Luffy goes for a rematch with Crocodile, and swallows a huge barrel of water to become a living water balloon. Crocodile is more than a bit surprised by this, though he recovers quickly.
Enel had the same problem but worse. At least Crocodile knew about his own limits, and had a fall back plan. Luffy not only bypassed Enel's invincibility, but then completely ignored just about every attack Enel tried to use in retaliation. And then the kicker was that there is no rubber in the sky islands. Enel not only didn't see Luffy coming, but he didn't know his main weakness even existed
Luffy's "execution" (actually an attempted murder) in Loguetown is prevented when the executioner is struck by a bolt of lightning. Luffy's flabbergasted allies can only conclude it was Divine Intervention. However, it's really a type 4 all around, maybe even an Idiot Ball moment. Why? They were atop a tall tower, the executioner wielding a metal sword, while thunder was rumbling in the background. Although it is well implied that it wasn't natural lightning that struck.
Zoro begs Dracule Mihawk to train him so that he can surpass and defeat...well...Dracule Mihawk. He's actually trying to get stronger for the sake of the Straw Hats, but, he's not forgetting his own goal in the process. Mihawk agrees to it, knowing that he's helping to create the one swordsman he believes can defeat him. Simply because Zoro is willing to throw away his pride for the Straw Hats.
When the Straw Hats enter the New World, Smoker falls victim to this in his attempt to ambush them. He knows that a New World log pose points to three possible islands, and he's Genre Savvy enough to know Luffy would pick the most dangerous of the three options. So he sets anchor by the most dangerous of the first three islands in the New World. What doesn't occur to him is that Luffy would instead go to Punk Hazard, an island that isn't even on the log pose.
Sabo. No one, not the Straw Hats, not Doflamingo, not even the audience saw him coming, making him a classic example of a Spanner in the Works. Makes you wonder what else the Revolutionary Army has in store for the rest of the series.
The Dressrosa arc of the story is basically a long chain of these on all sides, starting with Doflamingo changing the whole world's newspapers just to fool Law. Once the Straw Hats start their attack properly it gets to the point where somebody gets this every two chapters or so, culminating with Usopp somehow startling Sugar into fainting, and Doflamingo surviving having his head chopped off.
Doflamingo assigns a bounty of 500,000,000 Beri on "God" Usopp, which is even higher than the World Government's bounty on Luffy.
Chapter 273 is basically just Kurt's whole Gambit falling to pieces around him. First he reveals himself as a powerful Shinmeiryuu swordsman; Negi overloads his defenses. Then he claims they can't escape from his projected space; Chisame disables it. Finally he claims that no one knows they're there anyway; Asakura reveals that all of Negi's friends outside have been watching what's happened through her artifact the whole time. Then, just to top it off, he gets smacked with Ku Fei's artifact and Takamichi lamps him one from across the room.
Then right after that, Ala Alba's preparations promptly got shot to hell by the arrival of one of Fate's minions, causing their main retreat plan, as well as most of their backups, to fall to pieces.
In Pokémon Special, this is pretty much the only reason why Giovanni loses against Red in the two battles they fought against each other. First time, he completely dominated Red from beginning to end, took down all his Pokemon except Pika, and knew that he could take Red down before it could attack. How was he supposed to know Red stole Lt. Surge's gloves so that Pika could charge up its attack in its Pokeball? The second time, his Deoxys is beating him and Mewtwo. Too bad Bill and Celio, miles and miles away from the battle, manage to steal the jewels that were allowing Deoxys to form change.
In Naruto, Kisame Hoshigaki probably shouldn't have stopped to Kick the Dog after subduing Killer Bee- but who could have expected that he'd be betrayed by his own Empathic Weapon, leading to his defeat and death when reinforcements arrive? Certainly not the readers, that's for sure... ( Actually, he did see it coming, since his "death" was a Kansas City Shuffle to infiltrate the Cloud Village.)
What he did fail to see coming was that Naruto would be able to detect murderous intention, leading to his actual death.
In the first movie Ninja Clash in the Snow, there's a incredibly obvious Type 5: the evil ruler of Snow Country is trying to activate a machine that his peace-loving brother (who he overthrew) created under the assumption that it's a superweapon. The machine turned out to be a system of mirrors designed to warm the country and trigger spring.
Madara did not expect Black Zetsu to betray him, seeing as he's supposed to be the manifestation of Madara's will. He isn't; he's the manifestation of Princess Kaguya's will. Princess Kaguya was the mother of the Sage of the Six Paths, and the first ever chakra user. She's also supposed to be dead.
In Rurouni Kenshin during the Kyoto arc, Shishio has set up an attack on Kyoto as a distraction for his real goal: to take his pre-Dreadnought era Dreadnought to Tokyo. He wasn't too surprised that Kenshin read through this ruse, however he and his Dragon didn't know about Sano and frankly didn't care when he showed up. Until they found out he brought a former terrorist friends gift with him; a handful of bombs. It was this that managed to destroy the ship.
A Certain Magical Index: A type 4, bordering on type 5, screws up Aleister Crowley's plans big time when Shiage Hamazura, a completely normal Level 0, defeats a Level 5. From then on, Shiage Hamazura becomes an unknown variable to be accounted for, forcing Aleister to use up resources in order to eliminate the unknown variable.
Puella Magi Madoka Magica: for all of Kyubey'sBatman Gambits and deception to further his plans, he fails to account for the one thing he's been tempting Madoka with in the first place: Madoka practically wishes to overwrite the entire universe. Although he still gets his true goal in a different way: The Magical Girl system still helps counter entropy, and now finding out the truth doesn't lead humanity to resent him for it.
In Robotech: The Shadow Chronicles, the last words of bad guys are "This was not foreseen", this being an explosion with a blast radius of Millions of kilometers.
In The Legend of Koizumi when Taizo and Sanada faces off against Yukio, they were expecting a powerful opponent, especially with the whole alien theme going on. what they didn't expect was Yukio committing a Chombo, as in picking up the game pieces and punching Taizo in the face to void the game. Yukio would do this again, flipping the table, and somehow this boosts his luck for reasons currently unknown. Sanada would reply in kind, buy picking up the table and bashing Yukio clear across the room before the latter could flip the table again. Again, no one saw it coming.
The second season of Mobile Suit Gundam 00 has a type 4 situation, involving a hijack of a mobile armor by the enemy… only to be foiled by a Haro.
Aeolia Schoenberg, Dangerously Genre Savvy mastermind that he was, built Veda to account for things he didn't see coming: Veda ensures that his plan is fulfilled in spirit, and can make adjustments to the original plan if unknown factors crop up that Schoenberg didn't see coming.
Shimada serves as an Unknown Known for Rei during the Shishi Ou Cup in Sangatsu no Lion. Rei's so psyched toward engaging Gotou in the Finals match that he doesn't take the time to seriously consider how much of a threat Shimada can be, only to realize it too late when he suffers a humiliating defeat.
Bleach: Aizen is defeated by two things he fails to see coming due to the amount of false assumptions he had been making from the beginning. He wanted Ichigo to become more powerful but failed to understand how powerful Ichigo was capable of becoming and the Hogyoku suddenly de-powered him before he could complete his fight with Ichigo. Ichigo believes Aizen was de-powered due to possessing a deeply hidden desire to be a normal shinigami.
In Shogi, remember that it's possible to have your captured pieces used against you.
Since Go has a ridiculously complicated metagame deciding who actually controls territory on the board, it's possible to make unorthodox (or slightly less orthodox) moves that result in a massive advantage. (For a glamorized version of how this might happen, watch any match in Hikaru no Go.)
The Infinity War has a resurrected Magus employ a complicated scheme to seize all the Infinity Gems from Warlock and his Infinity Watch. Because the plan is too complicated requiring all his attention, the Magus literally doesn't see the combined efforts of Doctor Doom and Kang interfering with his plan.
Malekith the Accursed in The Incredible Hercules falls prey to this. One panel after he revealed his scheme. Who can stand against the mighty Grendell with Hercules and The Mighty Thor both weakened? Zeus. To add injury to insult, Grendell then fell on him. Probably a Type 5, as the plan was based on the assumption that Zeus was still dead.
In a Dracula vs Superman crossover Dracula was struck with an ignominious Type 5. His plan was to drink Superman's blood and thus gain the powers of a Kryptonian. Unfortunately he was not aware that Superman is solar-powered, and drinking his blood had a similar effect to trying to chow down on an active grenade.
In All Fall Down, AIQ Squared's plot falls apart when he fails to plan ahead for Siphon's Death Activated Super Power.
In the Spider-Man storyline Ends of the Earth, Doctor Octopus' final grand scheme was to flash fry all of humanity save .08% of them, so they can rebuild and remember him as the greatest monster that ever lived. When confronted with this, Spidey points out the big flaw in that plan: they'll live... brain dead - their brains would be flash fried, too!. Doc Ock promptly wigs out and Spidey takes him down.
In Fables, Mr. Dark has the Fable community to the wall. They can't run any more, and he is slowly shattering Haven's defenses. The Fables are planning a last ditch effort to defend themselves, but the chance of it actually working are slim. Then Mr. North, the North Wind, Bigby's neglectful father who he has had a serious love/hate relationship with, and who has often been shown to not really care about much outside his realm sacrifices himself to shut Mr. Dark down permanently. That it allows him to let his zephyr grandson live is a bonus. A slam dunk with #4.
In Mars Attacks!The Transformers, Megatron decides to use the Martian invasion as a chance to ally with them and take out the Autobots. Instead, the Martians capture both Autobots and Decepticons. As Megatron yells at the aliens and vows to kill them all, Cliffjumper points out that, as robots calling themselves "Decepticons", they should have seen this coming.
This tends to happen to heroes of Peggy Sue fanfics when the changes they make to the timeline come back to bite them in the ass. An excellent example of this occurs in Harry Potter and the Nightmares of Futures Past; Harry rants to Dumbledore about his living conditions with the Dursleys at one point, and Dumbledore responds by using memory charms on the Dursleys in an effort to improve the situation. When an unknown third party later removes the charms and Vernon remembers being charmed, Harry's already-rocky relationship with the Dursleys turns downright venomous, culminating in a savage beating during the first year/second year summer break that leaves Harry in critical condition.
Tzeentch's failure to see the C'tan plans coming was what forced the canon!40k gods to work together in Thousand Shinji. Continues into The Open Door, where newChaos forces occasionally find themselves facing things even the supposedly-omniscient and inheritor of Tzeentcch's mantle Tzintchi fails to see coming and thus pay for it.
Pops up left and right in Tiberium Wars, to both GDI and Nod. After all, GDI never saw the initial Nod assault coming, nor did Nod ever see Havoc's mini-guerilla war, fifty thousand GDI Marines, or a division of Mammoth Tanks coming.
In With Strings Attached, the completely unexpected appearance of mobs of skahs in Ehndris diverts the baddies' attention and gives John and Ringo the chance to avoid a head-on confrontation with the Raleka as they race to get into the warehouse.
Also, no one was expecting Kerrun to have a Villainous Breakdown and declare the skahs to actually be Idris (the mortal enemies of the Raleka), shifting the focus of the Raleka away from John and Ringo.
Jewel Of Darkness: Midnight's plan, to torture Robin into insanity in order to force the Titans to disband, ultimately fails because she had no way of knowing that Ai was possessed/working for Trigon, was plotting against her, and would ultimately sell her out to the Titans. Robin also suggests that the plan would have failed anyway, because even if she had succeeded in breaking him, he has faith that the team would be strong enough to withstand it.
The Dilgar War has a few of them, on all sides, but the most notable are Earthforce actually being able to take on the Dilgar best and not only win (this ability was Type 4 for the Dilgar high command, but Jha'dur knew they had the ability and tried to keep Earth neutral) but utterly annihilating them with an absurdly high number ofnuclear weapons (this was Type 4 for Jha'dur, who, when told of how many nukes were being fired at her, admitted she should have seen that coming but hadn't) and Jha'dur's attempt at exterminating Earth's population with a plague being ambushed by an unbelievable Type 3 in the form of a Minbari fleet led by Chosen One Dukhat in person who acted on information of the Vorlon.
In A Fighting Chance, the Minbari gets a major Oh, Crap when they realize that Earthforce has broken their stealth. This instance is part Type 4 and 3, as in the backstory of this fanfic the Dilgar had already did it once (and in fact they were the ones who sold Earthforce a few dozens of the stealth-breaking sensors complete with blueprints), but that happened to the Windswords who apparently never told anyone else.
In Game Theory, Precia's carefully laid plans repeatedly get hit with unexpected elements that screw up her strategy, but she manages to adjust accordingly. Only it turns out that one of the aforementioned Spanners In The Works actually opened up the possibility of pursuing a better plan, making it an inversion.
From Fantasy Of Utter Ridiculousness: Yukari Yakumo, Gensokyo's resident Chessmaster, admits as much when the moon is damaged in the wake of Coop and the Glorft's latest battle. Megas's unexpected teleportation into Gensokyo later sidelines her for most of the story.
Type 3 occurs in Serenity when the Alliance releases the Pax. No one could have foreseen the Reavers' creation Of course, their failure to do so is a classic case of the Idiot Ball, as what kind of a moron doesn't run proper clinical trials before dosing an entire fucking planetary population!
A type 4 occurs later in the movie when the Alliance's trap is derailed as Serenity charges at them with an army of Reavers.
Zoe: You know they're gonna see us coming.
Mal: No. They're not gonna see this coming.
The Coen Brothers movie Fargo centers around a man trying to get out of financial trouble by hatching an Evil Plan to have some men kidnap his wife and pretend to hold her for ransom so he could get some money from her wealthy father to pay off his debts. The plan spirals completely out of control and causes the deaths of about five or six people, including the wife.
Anchorman: The Legend of Ron Burgundy probably executed this in the most humorously absurd manner. When Burgundy and company start butting heads with another news group, they bring along multitude of weapons. Soon, other rival news groups join, and they all get into one large and epic battle royale. At different times, one person gets killed with a trident, another gets caught in a net and dragged on the floor by two horses, someone gets a hold of a grenade, Luke Wilson's character's gets an arm chopped off, and then his other arm is ripped off by a bear.
Frank:(after getting his arm chopped off out of nowhere)" Ugh! I did not see that coming!"
The Joker's reaction to the eventual result of his social experiment in The Dark Knight can be seen as an emotive example of this trope. Of course, being the Joker, he's not put off for long.
In Titan A.E., in a subversion of The Guards Must Be Crazy, the guard that the heroes are trying to fool instantly figures out that they're trying to pull a fast one over on him. Preed subtly leans over and asks if the group has a plan B. Stith beats the crap out of the guard, and leads Preed to the following quote.
Preed: An intelligent guard. Didn't see that one coming.
Type 4 occurs in the climax. The Drej have their entire fleet attacking the Titan station, hellbent on destroying it. Titan is running on auxiliary power, which isn't enough to activate the station. The Drej, being energy beings, are undefeatable...until the heros realize that Drej energy can be absorbed and converted into station power. The entire fleet is destroyed.
Once upon a Time in Mexico's Agent Sands had a nice Chessmaster scheme going. A number of things went wrong, including Cucuy going Face-Heel Turn and Mariachi and crew deciding to help the President instead of letting him die, but the one hitch that Sands truly did not see coming was Ajedrez turning out to be not only The Mole, but Barillo's daughter. Ajedrez even lampshades it: "You never saw it coming, did you?"
Which makes for a nice bit of irony (or something) as he shortly after loses the ability to see ANYTHING coming in an Eye Scream moment.
The type 4 is the whole plot of Under Siege with S. Seagal. Who would have thought that this annoying cook could be a threat to the very well conceived plan executed by the bad guys.
The type 3 is the plot of Under Siege 2 and a lot of action movies, like the Die Hard series, other of Seagal's movies and many others.
In Kick-Ass, Frank D'Amico never imagined that by framing the cop who refused to take his bribe, he would turn him into something far more dangerous. Big Daddy was so ridiculously efficient in destroying D'Amico's operation that if Kick-Ass wouldn't have accidentally provided him with a lead, D'Amico probably wouldn't have realized who was after him until he was about to die.
In the Kamen Rider Decade movie All Riders vs. Dai-Shocker, the Big Bad Shadow Moon has Decade and Kuuga right where he wants them when Kamen Rider Double comes out of nowhere for a Curb-Stomp Battle ending with Shadow Moon embedded in the wall of his own castle.
Richie Rich fits type 5 almost word-for-word, as the Riches do in fact keep family memorabilia in their safe. Their money, rather sensibly, has been invested and isn't vulnerable to just being swiped.
In Mystery Science Theater 3000, Crow did know that breaching the hull of the Satellite of Love would result in dangerous decompression... yet he still somehow thinks tunneling back to Earth is a good idea and is taken by surprise when it doesn't work.
Crow: Whooooooooooa I didn't expect this! [...] Wow, this is confusing! Mike! You wanna hand me me my calculations? [The wind happens to blow Crow's calculations right into his face.] Thank you. [Reading.] Well, look at that. "Breach hull—all die." Even had it underlined.
Jack Sparrow in general is type 4, no one (possibly including Jack himself) knows what he's going to do next.
In Clash of the Titans 2010, the heroes are all cornered by giant scorpions, then they are saved unexpectedly by the Djinn. No one ever expected that, not the characters or the audience.
The Spanish Prisoner: Almost everything that happened was planned out, but the plotters didn't predict that Joe would just happen to hang on to a book that one of them left fingerprints on.
The Italian movie Scialla has the protagonists Bruno and Luca survive the mob thanks to a type 3. Luca had stolen drugs and money from the mob boss' own home, and was so pissed that not even Luca's father Bruno giving him back everything as soon as he found out calmed him. The boss was about to make an example of them... Then realizes that Bruno was his favourite high school teacher that he still adores, and lets them go. The boss' underlings and Luca even lampshade this.
Played at and ultimately subverted in The Game when Nicholas invades the building of the organization that's been running his life for the past few days with what one of the lead actors recognizes as a real gun, not one of their props, and she pleads with him that it's all a big surprise party and they're not really trying to kill him and he ends up shooting his brother just as it turns out there really was a cake and it all flies horribly off the rails, driving him to jump from the rooftop... and then it turns out that, no, that was a squib, the gun's loaded with blanks, and even that was all in the script.
In Pumpkinhead, Ed Harley wants revenge against the kids who accidentally (and carelessly) kill his son. He has an old backwoods witch, Haggis, call upon a demon to do so. But he didn't count on enduring his victims' death agonies every time "Pumpkinhead" makes a kill. Or having his soul condemned to hell for invoking a demon to murder for him.
Just about any strategy of Harry's relies on him knowing something that the Big Bad doesn't, or him doing something the Big Bad couldn't have expected.
Wile E. Coyote. Suuuuuper genius.
In general, Harry has a lot of street smarts and fights really dirty. Regularly averting the Squishy Wizard trope, Harry is physically fit, somewhat trained in martial arts, has years of brawling experience, and almost invariably packs a gun. On one occasion some wannabe Practioners tried to challenge Harry to a magical duel, so he pulled out his revolver.
How Harry killed Aurora, the Summer Lady deserves special mention. Nobody ever thinks of the Little Folk, allowing Harry to smuggle them and some box cutters into the most pitched battle he could find. Just when he seemed spent... he opened the equivalent of a bag of poisonous bees in her face.
Harry, the famed wizard detective, hired a muggle detective. He subcontracted.
Despite the number of times that Harry gets thrown into situations that he knows less about than he should, he continues to wisecrack his way through. Very occasionally, the baddies bring something so far out of left field that even Harry is rendered speechless. Demeter, Lara Raith, and Nicodemus all had their moments.
Kringle, aka Santa Claus, has another name. Odin. Boy did he love dropping that bombshell on Harry.
The Big Bad's plan in Cold Days is brilliant, comes out of left field, and is the only fitting successor to the plan from Summer Knight we've seen so far.
Harry performed this on himself with a supernatural hitman and a memory wipe.
In the climactic duel in White Night, a Big Bad is taken by surprise when the ground he's running on suddenly turns into frictionless dust.
Now that Harry is buddies with the Genius Loci of Demonreach, he gets to regularly pull these off on the island when he's fighting people only running on mortal senses. Even immortal sense aren't as good as intellectus.
Grand Admiral Thrawn was playing a very effective game of Xanatos Speed Chess, until bitten by two or three Unknown Knowns. Specifically, Niles Ferrier botching his plan for the fringe, causing a group of independent smugglers to join the New Republic in battle; C'baoth killing the ysalamiri and escaping his imprisonment; and his secret cloning facility being discovered, all at the same time. All of this he might have been able to deal with. But the one thread that came loose in his plan, and led to his eventualdemise, was all caused by one single Unknown Unknown, or, as Timothy Zahn put it, a bit of information he didn't know and didn't know he didn't know: that Leia was Darth Vader's daughter.note Or, at least, that was the intention. The later Expanded Universe has had trouble deciding whether it was public knowledge or not. At the very least, he didn't know that the Noghri could detect that fact simply from Leia's scent.
In Yendi, a perfectly good plan to install Sethra the Younger as Warlord was foiled because Aliera and Morrolan were standing in the wrong places and then Aliera revived Norathar and Cawti.
The Culture has its own term for Type 3 situations — an "Outside Context Problem". For instance, a prosperous South Pacific island tribe suddenly discovering they've been colonized by an 18th-century European naval power — the kind of situation a civilization only encounters the same way a sentence encounters a period, once. The novel Excession revolves around one of these in the form of a Negative Space Wedgie.
In Ben Counter's Warhammer 40,000Horus Heresy novel Galaxy in Flames, when Angron attacks the survivors of their treacherous attack, Horus is enraged — with himself.
"Angron is a killer!" snapped Horus, rounding on his Mournival son. "He solves every problem with raw violence. He attacks first and thinks latter, if he thinks at all. And yet I never saw this!"
Later on, Lion El'Jonson, one of the deadliest combat primarchs, utterly destroys the favored Daemon of the God of Fate, impaling it through the heart as it gives him a fancy speech about how omniscient it and it's master are:
In Beowulf's Children, the sequel to The Legacy of Heorot by Larry Niven, Jerry Pournelle, and Steven Barnes, Aaron Tragon's (the Magnificent Bastard of the novel) schemes to colonize the mainland of the planet and becoming the new leader of the colonists is derailed by a rather spectacular Unknown Unknown. After shooting Little Chaka and Cadmann to keep them from warning everyone of the imminent continent sweeping attack of the recently discovered huge flesh-eating "bees" with Super Speed, all in order to keep everyone from leaving, he goes back to the colony and tells everyone a story of how they were devoured by grendels. He puts on a very convincing act of grief and shame, while preparing to take the reins of leadership left behind by Cadmann. All of a sudden, the intelligent grendel protagonist approaches the colony, having saved Little Chaka, who proceeds to blow the whole scheme out of the water by telling everyone of Aaron's betrayal. The only reason Aaron avoids execution on the spot is the untimely arrival of the aforementioned flesh-eating "bees" with superspeed.
Tyrion is left badly injured after a battle, and while he's comatose, every single one of the men on his side is either turned to Cersei's side or replaced. Given the circumstances, he manages a spectacular recovery, which is promptly destroyed when Joffrey is murdered and Tyrion is framed for it. It's yet to be seen whether or not he will manage to come back from this one, but he's probably going to meet Daenerys soon, and Tyrion's most beloved dream has always been to ride a dragon...
Cersei resurrects the Swords and Stars and has them charge her rival with treason; unfortunately, the Swords and Stars decide to torture the man she sent to testify against Maergery, and, trying to save himself, he tells them everything, including Cersei's own crimes. Then, just to rub salt in the wound, her actions towards Jaime come back to bite her in the ass when he refuses to champion for her and instead continues on his own campaign.
Arguably, the entire country of Westeros got screwed when Eddard Stark met Joffrey Baratheon. Instead of allowing Lord Stark to live in exchange for a false confession, the newly-crowned Joffrey has him executed, and thus the War of the Five Kings is kicked off with a bang.
Tywin Lannister certainly didn't expect a vengeful Tyrion shooting him in the bowels with a crossbow while he was in the privy. Of course, most people don't expect they will die on the toilet.
The villains of the last Narnia book The Last Battle; Shift, Ginger, and the Calormene warlord Rishdan, all meet a nasty end due to one horrifying Unknown Unknown: the demon Tash is real. And pissed.
Archmagos Khobotov in Soul Drinkers discovers a few problems with his plan for stealing the Soulspear and back-engineering it - one Unknown Unknown and two Unknown Knowns.
The Doctor Who short story collection "Short Trips and Side Steps" featured a story called 'The Android Maker of Calderon IV'. The title character has meticulously engineered a plan to get revenge on the Third Doctor (who thwarted his plan to set up a technocracy) and assassinate the planet's government by building an android in the form of the Doctor responsible as a suicide bomber. Then he activates the return beacon the Doctor left behind...and the Fourth Doctor steps out, giving us a demonstration of the Unknown Unknown, and a marvellous quote for anyone who's ever been on the receiving end of this trope:
A Type 4 blows up the Big Bad Storm King's Evil Plan in Tad Williams' fantasy epic Memory, Sorrow, and Thorn. Specifically, he didn't care who showed up for the final ritual to unite the Three Swords and reverse time so he could return to Osten Ard, but one of those people turned out to have been primed to figure out his weakness at the very last second, and another happened to be carrying the Chekhov's Gun necessary to defeat him afterwards.
Sauron was right, in fact—nobody denied the power of the Ring in the end. Of course he couldn't possibly fathom that one of those would be idiot enough to victory dance on a cliff above a massive lava pit...
Tolkien noted in correspondence that part of Saruon's problem was a more basic miscomprehension; he believed that after the Fall of Númenor, God had ceased to care what happened to His creation, that the Second Fall of Man had been the last straw. He was wrong.
Sauron really had won, by all accounts. Aragorn's army was hopelessly outnumbered, and Frodo had claimed The Ring for himself. In a way, this trope is double subverted. Early on, Gandalf notes that they have the advantage because Sauron cannot comprehend the idea of someone trying to destroy The Ring. What Gandalf didn't see coming was that Sauron was right. In Mordor, where the Ring's power was greatest, no one could resist it. Sauron's flaw was an example of Genre Blindness. He assumed that Middle-Earth is a Crapsack World, when it was not. What he didn't see coming was the almost literal Deus ex Machina that caused Gollum to fall to his death. As it was an accident, the only real way to interpret this is an act of fate.
Some see Gollum's fall as a way for Tolkien to avoid forcing Samwise to execute a Hero Maneuver. When first read, Frodo's failure and then Gollum taking the Ring from him looked a lot like a setup that would allow Sam to knock or tackle the Ringbearer into the lava without the rather unbelievable concept of being able to do it to his best friend. The accident simply meant that the pair got to survive the war together, but Sam's presence meant that success didn't have to rely on luck alone.
And yet another is that Gollum was under a geas from Frodo; that he never let Sauron have the Ring; ever. (He swore by the Precious.) Once Gollum had the Ring over the brink of Mount Doom; there was only one way to fulfil the geas. (Not that Gollum was conscious of what he was doing.)
In Cain's Last Stand, Varan gets hit by type three in that he didn't know that Cain's aide, Jurgen, was a blank, so when he met up with Cain to discuss the terms of surrender, the psychic ability that allowed him to instantly convert people to his cause wouldn't work. Cain ends up kicking his ass off a skyscraper. Literally.
Lord Vetinari subverts the trope by accounting for Didn't See That Coming. Instead of planning, he waits until the unexpected (or the expected—he has a very firm grasp of human nature) happens, then drives the situation to his advantage from there. Even when it seems like he's miscalculated, people prove every bit as stupid or clever, dogged or unmotivated, loyal or treacherous as he expects. He is a master at Xanatos Speed Chess.
In latest addition to The Wheel of Time series, The Gathering Storm, Rand pretends to begin playing Graendal's game of manipulation and subterfuge, then obliterates the palace she's in with a column of balefire.
How do I outthink someone smarter than I am?
The following book subverts this. Apparently, one way to handle Unknown Unknowns is to spy on your enemy until the last possible second, and have someone around that can serve as a body double...
Harry Potter: "Nobody will ever guess that I've made Soul Jars, and even if they do they will never find them. What? They did and they did? FUUUUUUUUUUUUU-"
The legacy of the Elder Wand, which Voldemort so desired in Deathly Hallows, was supposed to die with Dumbledore, by having Snape kill him by his command. However, unexpected and unbeknown to everyone till the very end, Draco Malfoy had already inadvertently gained the wand's allegiance at the end of The Half-Blood Prince by Disarming Dumbledore (thus defeating him) beforehand. Then a few months later, Harry overpowers Malfoy at the Malfoy Manor, which subsequently transfers the Elder Wand's ownership to him. According to wand lore, one only has to defeat the Elder Wand's current master to win over its ownership; whether the previous master was in possession of the wand does not matter. Thus, even though Voldemort is in possession of the Elder Wand in the final battle, he cannot unleash its full power, nor can he harm Harry with it, as the wand has already sworn allegiance to Harry, making him its true master.
Also counts as an unknown known: Voldemort believes that Snape is the true owner because he killed its previous owner. Its previous owner was Dumbledore, who got it from Grindelwald, who was killed by Voldemort. Oops.
The Big Good Dumbledore gets his own moment. He's a supremely intelligent wizard, completely in control of himself, plans years and years in advance and all his guesses, intuitions and plans come exactly as he wishes. The one mistake he makes? When hunting for Voldemort's horcruxes, he's unprepared for the fact that the chosen object was in fact a lost artifact in its own right, the Resurrection Stone - The Remnant of a quest Dumbledore abandoned nearly 80 years ago, which cost him the life of his sister and his relationship to his brother. Confronted with a single opportunity to meet his sister and beg for her forgiveness, Dumbledore let his guard slip and fiddled with the object despite it being cursed (which he knew fully well). This resulted in him getting a curse that makes him Secretly Dying for the better part of a year. What makes Dumbledore so awesome is that he's able to capitalize on his own mistake and have it adjust into a pitch perfect end-game.
"I make mistakes like the next man. In fact, being—forgive me—rather cleverer than most men, my mistakes tend to be correspondingly huger."
Caesar from Matthew Reilly's Area 7 puts a microwave transmitter on the president's heart, so that he can set explosives to blow up half of America the moment he dies. He also puts one on his own heart to prevent the heroes killing him if his plan fails. He didn't anticipate that the heroes could fake the signal using the black box from an AWACS plane allowing Schofield to just shoot him.
Lit make mistakes like the next Septimus Heap - Magyk: This is DomDaniels reaction when Marcia reveals that the Apprentice the Heaps have just saved is actually him.
In the fourth Earth's Children book, Plains of Passage, Attaroa tries to kill Ayla to show her tribe what happen to those who resist her, only to be killed by Wolf, who has been hiding in the woods. Since Wolf is the world's first domesticated wolf, there really wasn't any way Attaroa could have even suspected that he exists.
The appendix of Dune (the first Dune book) argues that the Bene Gesserit order should have foreseen that the Kwisatz Haderach they were trying to create would not serve the order.
They were also making it easy for their members to fake being messiahs in case of emergency, so they underestimated the real thing.
This is a billiard table... And you have hit your white ball and it is traveling easily and quietly towards the red. The pocket is alongside. Fatally, inevitably, you are going to hit the red and the red is going into that pocket. It is the law of the billiard table. But, outside the orbit of these things, a jet pilot has fainted and his plane is diving straight at the billiard room, or a gas main is about to explode... And the building collapses on you and on top of the billiard table. Then what has happened to that white ball that could not miss the red ball, and to the red ball that could not miss the pocket? The white ball could not miss according to the laws of the billiard table. But the laws of the billiard table are not the only laws.
Callahan's Lady has a couple of doozies in its final story. The Professor, the World's Greatest Conman, bought $50,000 in counterfeit ten-dollar bills from Tony Donuts. After the money had been disposed of, Tony demanded the bogus bills back, so the Professor was forced to rob a bank, to pass real money to Tony for his fakes. Unfortunately, after bringing Tony the nice, neatly bound sequential bills, Tony realizes the money isn't his counterfeit cash, because he'd never figured out how to work the serial number increment mechanism on his press, and thus all his counterfeit money had the same exact serial number. Perfect example of a type 4; clever people have troubles properly accounting for real stupidity.
Mission of Honor. Manticore was on alert and ready for trouble, but Oyster Bay still succeeded because the Mesans were not using impellers, which the Manties knew to look out for, but their new spider drives, which were a completely new technology.
The Solarians have been screwed multiple times by the Unknown Known of Manticoran and Havenite technology being well ahead of theirs. It's not as if they didn't consider the possibility; they just rejected it out of hand.
The discovery of the Lynx Terminus of the Manticore Wormhole Junction (which no one could have predicted) disrupted the Alignment's plans, forcing them to bring about the Manticoran-Solarian conflict ahead of schedule. Unfortunately, this is at least part of what led Queen Elizabeth to make peace with Haven. If it hadn't been for the Solarian threat, she probably would have simply forced Haven into submission. However, they also didn't anticipate Herlander Simoes' defection, which led to the Manticorans and Havenites learning about the Alignment and forming a military alliance. On the one hand, this will help bring about the downfall of the Solarian League even sooner. On the other hand, the fact that the Grand Alliance doesn't know about the Renaissance Factor or where the Alignment's base is is the only thing keeping them alive.
The Mesan Alignment also got shafted by Oversteegen kicking their ass at Tiberian, the entire clusterfuck in Crown of Slaves that resulted in the establishment of the Kingdom of Torch, and HMS Hexapuma catching a Jessyk freighter using a false transponder, and that one only happened because Aikawa Kagiyama was bored and decided to do a detailed analysis of a random ship for fun. In fact, they've been having a major problem in this department for some time, starting with Manticore managing to stand up to Haven in the first place.
Pretty much the reaction of the Malwa Empire and Link every time their carefully-made plans encounter the titular Byzantine general of the Belisarius Series. A prime example was when he walked into an enemy-held city as a nameless "prisoner" of a unit of Kushans who'd changed sides that the enemy had no idea existed; the men were believed to have been wiped out with the rest of another Malwan force that had been obliterated.
A spectacular type four happens in the Codex Alera book Princeps' Fury to Gaius Sextus during the fall of Alera Imperia
Gaius: Crows. Didn't even look at them twice
Nuklear Age's Dr. Menace encounters one every few seconds, as one after another of her plots fail in Deus ex Machina style. Her first kidnapping plot failed when a just-introduced supporting character happened to catapult into her abandoned warehouse base, destroying the building, her orbital death ray failed when Nuklear Man decided to show off by firing a Plazma Beam into the sky, her plan to convince Nuklear Man to turn evil via telepathy failed when Dr. Genius happened to contact him telepathically soon afterward and he mentioned it in passing, her plan to capture her alien visitor failed when the alien happened to be an nigh-omnipotent god... Her plans not only failed, but failed in the most frustrating style possible. It is mentioned several times that she was finding it more and more difficult not to start screaming.
In The Scar, Silas Fennec succumbs to a Type 4 when he overlooks Armada's tugboats and their potential as explosive ramships. His oversight directly leads to the utter decimation of the New Crobuzon fleet.
In the backstory of the Mercy Thompson series, a trophy wife kills her husband with a pair of gardening shears, and pins the blame on the gardener. How was she to know he was a fey, who can't touch iron without being burned? And even if she somehow knew that, how was she to know the Grey Lords had chosen this moment to break the masquerade?
In Jack Campbell's The Lost Fleet novel Invincible, Desjani warns that her great plan is also a terrible plan because they know so little about the aliens that it relies on some assumptions that could easily be thrown off. They go with it anyway, though.
The Forerunner Saga reveals the truth about the connection of the Forerunners and Humans in Halo. Humanity use to be an interstellar empire and were allied with the San 'Shyuum(aka the PROPHETS) in their war against the Flood. Plus they also ended up fighting with the Forerunners over territory, the Humans have defeated the Flood, but lost to the Forerunners who devolved them back on Earth.
In Honor Harrington: The Short Victorious War, the People's Republic of Haven opens the war by covertly preying on Manticoran shipping, ambushing convoys with superior forces. One such raid goes pear-shaped when, instead of the lightly defended convoy they expected, Battlecruiser Divisions 141 and 142 drop out of hyper within energy range of the dreadnought HMS Bellerophon, which by a complete fluke was passing through the system while rotating home. The Peeps even manage to get off the first shot, but cause only minor structural damage before the dreadnought's return fire pastes them. And the best part? It was the night shift, and Bellerophon's officer of the watch was a communications officer who won by reading down a list.
Live Action Television
Pretty much every episode of Leverage, starting with Episode 1.
An episode of Star Trek: Deep Space Nine featured the return of a bunch of hyper-intelligent, genetically engineered "friends" of Dr. Bashir's, who, upon thinking on the Dominion war situation, decide it was in the best interest of all involved if the Federation surrendered or was defeated quickly and the Dominion won (which would save billions of lives in the long run, and end in a galaxy-wide rebellion to overthrow it). They go to give the Dominion some classified Starfleet tactical data, but are stopped when one of their own tells on them. Dr. Bashir rubs it in, explaining that if one person can uproot their brilliant plan, then maybe their calculations might become nil due to the uncalculatability of human nature.
A very subtle double example, as the payoff is in an earlier episode: the Dominion worked out the exact same projections, and had a counter to it: When they won, they were going to purge Earth, as an example.
In an episode of Torchwood, a paedophile tries to force a little girl into his car. He really had no way of knowing that fairies were interested in the girl and that they were not the Disney kind...
In Children of Earth, Jack Harkness falls prey to a Type Four: he knew that the 456 were capable of curing viruses deadly to humans, but it never occurred to him that they could create and instantly release one if anyone tried to resist their demands. And he learns this in the worst way possible.
The Volume Four finale of Heroes, "An Invisible Thread" involves Peter having used Sylar's shapeshifting power to impersonate the President, heading off Sylar's attempt to shapeshift into the President and become him. From Peter's dialogue, it is clear that Sylar probably knew that Peter had replicated one of his powers, but wouldn't have expected him to have taken something so mundane.
The Volume Four premiere had a Type Four. Danko, having rounded up most of the specials and put them on a plane to a detention facility, agrees to free Claire in order to mollify Nathan Petrelli (her father). He admits that her power (regeneration) doesn't make her a threat to society. However, he didn't know that Nathan has no real control over Claire, or that being immortal and all but immune to pain means that she can and will carry out acts normal people would consider suicidal. Claire escapes from Nathan, gets on the plane via the landing gear, frees the captive specials, and ends up causing the plane to crash. Now the government has to round up the specials all over again, only this time they're actively evading capture.
Stargate SG-1: After capturing SG-1 in a planet he recently conquered, Cronos decided to publicly execute them so that the locals would see how foolish it is to try to resist him. Unfortunately for him, during the execution it was revealed that they were actually SG-1 robotic Doppelgangers. Kind of hard to keep claiming to be an all-knowing god when you can't even keep your jaw closed.
In The Office (US) every time Dwight tries to do something manipulative it falls prey to this. He even lampshades it.
Just once, I would like to be a puppetmaster and have nothing go wrong. Just once.
The Master had planned to kill Buffy, gaining the power to escape his prison and open the Hellmouth, bringing about The End of the World as We Know It. If he thought about Buffy's allies, he dismissed them as powerless. Unfortunately, while his plan to kill Buffy worked, Xander knew CPR. Buffy therefore returns from the dead, and proceeds to kill the Master. Considering the Master has been in a prison for hundreds of years, it's possible that CPR itself was an "unknown unknown" to him. The idea that a human could come back to life through non-supernatural means may well have been completely foreign to him.
In Season Two, Spike and Drusilla had a plan to destroy the world. They had resurrected the Judge, a demon who, according to prophecy, could not be killed by any weapon forged. They did not take into account several hundred years of advancement in weapons technology, and Buffy blew away the Judge with a rocket launcher. Given that The Judge was defeated last time he rose up too, they might not have actually expected him to destroy the world (which Spike rather likes), but they were certainly expecting a bigger death toll than two. One of which was one of their own minions.
On Covert Affairs, Auggie experiences a 4-5 combination when he appeals to his ex-girlfriend Natasha for help on a case, and is somewhat surprised and dismayed when she refuses to help, still angry that he landed her in jail previously. He says the trope name verbatim when she slaps him upon their first reunion...except he means it literally, having been blinded since their last encounter.
In Babylon 5, after Jha'dur, the last Dilgar was captured; she managed to get a pardon in exchange for developing her immortality serum. Just before she was about to go to earth she gloated to Sinclair that the serum can only be manufactured by killing other people and that her capture was actually part of her plan to make the rest of the races just as bad as hers was. What she didn't realize was that the vorlons were not the enigmatic reclusive weirdoes that they seemed to be, but were actually manipulative Precursors who saw right through her plan and destroyed her ship to stop it. Also, since the vorlons themselves were forced to act openly and directly instead of manipulating events from the shadows as they usually did, Jha'dur herself could be considered a Spanner in the Works.
JAG: In 1st season episode "Sightings", Colombian drug smugglers use the underground facilities of a supposedly abandoned navy base in Texas where they have a cocaine processing facility without the locals knowing anything about it. Obviously, they didn’t foresee that the disappearance of a young local girl would lead the Navy to send two of its most resourceful investigators and foil the whole operation.
Gatehouse gets this in his first encounter with Glickman, when he realises that Glickman knew he was coming in advance and prepared countermeasures; namely, a large bomb, which destroys his shop and almost kills Gatehouse.
In the next episode this happens to Glickman himself. He contacts his girlfriend not knowing that she's working for Counterpoint. She then stabs him to death.
In Kaizoku Sentai Gokaiger, former The Dragon Damaras has defeated the Gokaiger, capturing Captain Marvelous for execution, killing the others, and letting Lovable Coward Don live out of mercy. Then his plan gets completely derailed when Don actually comes back to mount a rescue, relying upon their little-known Team Pet to rescue Marvelous while he distracts everyone else (and is lampshaded by Marvelous' Evil Former Friend Basco outright saying the trope's name when Don first shows up). And then we find out that Basco only faked killing the other Gokaigers, which he reveals as he literally backstabs Damaras.
In Blackadder the Third, Edmund is tied up on "an unrealistic grassy knoll" by the highwayman The Shadow, who plans on coming back to kill him later. Just when all hope looks lost, his Bumbling Sidekick Baldrick shows up, wanting to get the Shadow's autograph. Blackadder thanks Baldrick for teaching him an entirely new sensation: being genuinely pleased to see him.
Salem: Rose claims that she has seen and manipulated everything that has happened, including Mary killing Mercy. Turns out Mary turned Mercy into a witch, and Mercy then swiftly beheads Rose.
Played for Laughs in Friends when Rachel tries to teach Joey sailing, but finds herself turning into her father in the process; when she figures it out, she laments that she was trying so hard to not become her mother that she never saw this coming.
On the one hand, Game Masters are very often on the receiving end of PC ADD (not AD&D, though the similarity is telling) and are often forced into Railroading the plot. On the other, PC's can be struck by a very creative GM who gleefully goes Off the Rails with them and reprimands misbehavior creatively.
One example took place in the Gothic War. Chaos runs in and has the Imperial Navy on the ropes, they're clearly winning with their plans falling perfectly into place. Then out of the blue the Ork pirates which have been pestering the Imperial decide it might be fun to attack Chaos for a while.
The bread and butter of the Alpha Legion, to the extent where their very existence has been denied by the Imperial Inquisition three times. It's not really clear who's side they're even on.
There was the time when Craftworld Iyanden was getting swamped by an Ork Waaagh!, forcing them to raise even more Wraiths. Then out of the Webway the Dark Eldar come in to save the Craftworld Eldar, their reason they were amused to the Eldars angst in summoning the dead.
Happens to virtually everyone in Exalted, especially when Adorjan or the Exalted are involved. Let's put it this way: in Autochthonia, one of the nations implemented a form of currency to keep the Populat happy during a series of high-profile scandals. Now there are illicitly wealthy members of the Populat bribing their way out of their responsibilities, regulator corruption all over the place, counterfeiting rings springing up, and similar chaos, and nobody has any idea what to do about it.
The Clan Invasion in BattleTech, the Inner Sphere did not expect facing powerful high tech invaders with technology far more advanced than anything they have.
Thrill Me, in a case of known unknown: Richard knows that Nathan exists, and is, in theory, aware that Nathan is smart. Nathan can, after all, hold his attention. Richard does not expect Nathan to pull a Xanatos Gambit for the sole purpose of keeping the two of them together (in life or death).
Ol' Bobby seems to have a real problem with AI's. Another AI that his organization was using for anti-terrorist operations went rouge when it classified them as terrorists, then began actively sabotaging their plans. And, of course, he made the classic Villain flop-up by continuously underestimating JC's abilities.
Calypso sometimes runs into this in Twisted Metal; he doesn't always pick the most dependable players. In fact, the only two games in the series where he doesn't utterly and completely lose at least once are Twisted Metal 3 and Twisted Metal 2012.
Sweet Tooth tends to do this most often, but he's gotten caught off-guard by others as well. At least four characters turn the tables on him in Twisted Metal 2. Even when he took over Twisted Metal 4, he got his ass handed to him four times (Forced to take DRIVING SAFETY CLASSES, forced to act as chauffeur to an annoyingly crazy family, arrested by a bounty hunter, and trapped in his own Soul Jar).
And it happens again in Persona 4, if you manage to find the true ending. The game itself works against you here, making you wait until most of the way through the good ending and then ignore two of its attempts to turn you around, that it's really no wonder the true final boss is surprised you got that far.
In Command & Conquer, Kane's always a step ahead. Of everyone. GDI, Scrin, his own generals. Then in Command & Conquer 3 he undergoes a Villainous Breakdown when Kilian's forces ally with GDI. And then in Kane's Wrath, when it's revealed just how proficient Kane is at playing a Gambit Roulette, he's yet again surprised when Alexa reveals to have tried to destroy LEGION, and tricked Kane into executing Kilian, out of her devotion to Kane. That said, he still wins out in the end.
In the First game its seemed as though Nod has successfully defamed GDI and caused the UN to cut off all funding from them leaving them vulnerable for their forces. But instead it was all a Batman Gambit by GDI to trick Nod into lowering their guard, when Nod forces began attacking GDI bases they ended up facing fully armed forces.
Planescape: Torment has a backstory example: Fhjull Forked-Tongue, Lawful Evil devil manages to trap a deva, a very incarnation of truth and Lawful Good, only to have it undone by the fact that the deva lied to him. The result of this (which is never precisely explained) is that Fhjull is now trapped into performing charity to any who asks.
In BlazBlue: Calamity Trigger, Hakumen says a variation of this in his Arcade path when Nu-13 turns out to be the ninth fight instead of the last one.
Hazama runs afoul of this trope in Continuum Shift Extend, variant 3X. Here's the rundown. During the events of Wheel of Fortune: Calamity Trigger, Hazama makes an attempt on Jin's life, only to have himself parried by a half-dressed squirrel beastkin he initially recognizes as Makoto Nanaya, but when she asks about Noel, who was obliterated in Ibukido during this timeline, he starts running questions through his mind on just who she is. This Makoto, as he finds out far too late to salvage the rest of his Wheel of Fortune plot, is actually an extracontinuual anomaly, and not only has she been asking questions about things that didn't happen in Wheel of Fortune, but she also brought Noel up before Tsubaki Yayoi - the resulting confusion caused Tsubaki to not meet with Hazama for prescheduled mindrape, so Hazama has to come up after her, and since Continuum Shift Makoto has been in recent contact, she was nowhere near Relius, who Hazama was outsourcing her handling to. His plans completely toppled and his patience having expired, he decides to kill her where she stands - only Rachel shows up and gets her out of there, leaving him alone with his seething rage. Back in Continuum Shift, when Hazama catches Makoto chatting with Jin and not on assignment in Ikaruga, he finally puts two and two together, and his actions relegate his newfound priorities with her - outsource to Relius or kill on sight!
Hazama, once again, runs afoul of this trope in Chronophantasma - this time, Type 4, against the exact same perpetrator.Got time to kill? Having completed everything in Continuum Shift proper according to his own specifications, he is confident enough in his ability to control affairs that rather than keep Tsubaki Yayoi (the wielder of the Izayoi and Hazama's anti-Hakumen shield) on a tight leash with him at all times, he lets her run around Ikaruga on her own. This is in blatant ignorance of the fact that the last time he caught Makoto and Tsubaki with each other happened to be the instance mentioned above. True enough, Makoto finds Tsubaki, only Kagura Mutsuki happens to interrupt the fight and let Tsubaki run free. After being filled in (and likely getting a knuckle sandwich or two for his trouble), Kagura orchestrates a trap to lure Tsubaki back to Makoto, Noel and Jin to break her brainwashing, and the trap works as intended. Afterwards, Terumi gets into a fight with Hakumen, and when he thinks he can evade Hakumen's Time Cutter, Trinity pins him in place so he can't - and because Tsubaki is now off fighting alongside Makoto against Relius and his cadre of puppets, Terumi can't use her to stay Hakumen's blade. Due to synchronization, both Hazama and Terumi are now dead.
In BioShock, Fontaine's plot to get Jack to kill Andrew Ryan to let him take over Rapture went of without a hitch....except for those Little Sisters....
No one seemed to see Yuna and her Guardians coming, least of all Lady Yunalesca, who has never been challenged before and was certainly not expecting to get the shit kicked out of her horrifying medusa-head form, thereby destroying the traditional (but not, as she claimed, "only") way to defeat Sin.
Nobody predicted that Sin itself, or rather Jecht, was capable of setting into motion events that would lead to its destruction.
In Final Fantasy XIII, Barthandelus' plan to turn the l'Cie into the instruments of Cocoon's destruction hinges on them breaking when he slams them into the Despair Event Horizon, inducing them to follow their Focus and using the power of Ragnarok to kill Orphan. Fang comes close in the end, but not close enough: Barthandelus' failure to recognize humans as more than mere tools is the undoing of his schemes, as the l'Cie ultimately save Cocoon by subverting their Focus.
Sun Li, Glorious Strategist for the Jade Empire. Yeah, marvelous plan. Flawless, right down to deliberately putting flaws in the Player Character's fighting style. But...he really didn't expect that The Water Dragon was running an equally good one to counter it.
In Mass Effect despite the Reapers being terrifyingly thorough when it comes to wiping out all life in the galaxy, they still can't foresee every outcome:
The Reapers didn't plan for the Protheans to stop the keepers from activating the Citadel Relay. Nor did they anticipate the keepers evolving in manner that could be exploited to this end. This is noteworthy as it also relied on the Reapers only weakness: their expectations. They expected the Protheans to futilely fight until extinction. They didn't expect them to accept their fate and Fling a Light into the Future, essentially using their last fighting chance to give future sentient life better odds of survival.
Harbinger recognized Commander Shepard as a major threat, and had him/her eliminated. He didn't count on Cerberus being able to resurrect Shepard, rebuild the Normandy, and point him/her right at the Collectors.
The original Shadow Broker didn't see the betrayal by his Always Chaotic Evil yahg agent until it was too late.
In a Mass Effect novel, the Illusive Man captures Paul Grayson, a rogue Cerberus agent, and has him implanted with Reaper nanites, effectively turning him into a Saren-type Husk. He keeps Grayson sedated and has Kai Leng on standby to kill Grayson if necessary. Then the research station is attacked by a turian squad sent to stop Cerberus and rescue Grayson. The Illusive Man's plan is ruined, and he barely escapes with his life. Unfortunately, the turians experience this as well. They rescue Grayson but have no idea that he's already under Reaper control.
In Mass Effect 3, Javik reveals that the Protheans had actually intended the Asari to lead the Galaxy against the Reapers in the next Cycle; influencing their early civilisation in order to give them a decent headstart. Upon waking up from 50,000 years of hibernation, Javik is naturally taken aback to discover that they're sitting on their hands, while it's Humanity who are leading the charge.
In the Citadel DLC, the Mysterious Figure is remarkably prone to this: not bothering to trap Glyph and allowing Traynor to grab her toothbrush before leaving both come back to bite said Figure in remarkably elaborate ways later on.
Mass Effect 2 squad member Mordin Solus relies on this trope to give him an advantage when going into a dangerous situation. He states in a conversation with Shepard that people see species like turians and asari as obvious threats because of their strength and capabilities, but because he's a salarian (amphibious lizard people who are comparatively physically weak as a species, yet intellectually superior), his enemies "*sharp inhale* never see me coming". Extra points for the Slasher Smile with that last bit, and for being ex-special ops and plenty dangerous in his own right. Omega quickly learned not to judge him by his diminished physique and spastic behavior (especially after he displayed the bodies of several mercs who tried to extort money out of him outside his ghetto clinic as a warning to others).
Several of these nail Manfred von Karma. He didn't see Larry Butz arriving with key information, didn't expect Phoenix to get useful information out of a parrot even after retraining it to destroy the most useful, and, most importantly, he spends the entire case manipulating the Judge... but never expects the Judge to truly hold devotion to law and order over any fear he may have of him. This last one screws von Karma over more than everything else.
Also, in Miles Edgeworth's game, Quercus Alba is unbeatable, until a series of these brings him down. Notable in that multiple completely unpredictable (from his perspective) events are required for him to be arrested.
In Kingdoms of Amalur: ReckoningTirnoch created the Fateless One so that he/she could free Tirnoch from her prison that she was destined to hold her forever. This part works perfectly. What Tirnochdidn't see coming was the Fateless One being powerful enough to kill her.
In Skyrim, the Thalmor were quite confident the Civil War in Skyrim would ultimately end in their favour. If the Imperials won, their Thalmor allies would be free to continue their efforts to infiltrate, influence and undermine a province of the Empire. If the Stormcloaks won, the Empire would be weakened significantly, recall their troops and leaving Skyrim wide open for the Aldmeri Dominion to launch an invasion. What they didn't see coming was the return of Alduinthe World-Eater, the resurrection of the Dragons, and the arrival of the Dragonborn.
The Dragonborn can potentially end up throwing a huge wrench into the Thalmor's plans for Skyrim by siding with either faction: either they face a reunited and re-invigorated Empire, or a still fairly powerful and not-being-continually-drained Cyrodiil and a rather powerful and very hostile independent Skyrim, and either winner also gets a new ally in the form of a Physical God.
Hyperdimension Neptunia Victory: Mr. Badd's plan to neutralize all the goddesses in Gamindustri worked flawlessly, leaving him and his organization free to move in and take power. He didn't count on a foreign CPU to show up and derail the step of the plan.
In Silent Hill, Dahlia didn't count on Kaufmann having more than one vial of aglaophotis.
In Fallout: New Vegas, the Independent Path ends with the 4 year-long-struggle between the Legion and NCR for control over the Mojave, as well as the 200-year-old plans of Mr House, completely derailed by one lone package Courier.
While Mr House, the NCR, the Legion or Yes Man send the Courier to parley with the various minor factions to rally support for their side in the second Battle of Hoover Dam, the one faction none of them expected to get was an elderly contingent of Enclave Remnants from Navarro, whom your companion Arcade can introduce you to.
In the original [[Homeworld the Taidaan Empire fell due nobody anticipating the Kushan Mothership escaping the Kharakian Genocide, creating a powerful fleet and invading from the unguarded border as they were busy with a large rebellion.
Kale Williams utters those exact words in the Quetza Drake's Furthia High comic, when Campy shows up to the school dance with a male date.
Ashley averts it when she calmly replies, "I did."
In an XKCDcomic, some nerds figure out how to end all relationship drama (via a mathematic equation, naturally), but upon testing their theory in the real world, all the relationship drama, in fact, SPIKES, leading one to say "Holy shit... people are complicated!
The defunct webcomic Filthy Lies had one character daydream a Self Insert fic where he was a Jerkass Stu (using Felix Felicis, for example, to have a threesome with Hermione and Ginny) in the events of Harry Potter and the Half-Blood Prince...who, during the climax, ended up screwing everything up so that all the good guys died. He even took the big moment away from Snape by accidentally bumping Dumbledore off the top of the tower with poor broom handling before Snape could perform Avada Kedavra.
Snape: I did not see that coming.
In El Goonish Shive, when Abe disarmed the elf. Anybody who forgets he's fighting a wizard after having to overcome his spells just to get there deserves to be spammed by exploding crows on the spot.
A chain of these in Alanna. Tristan has forcibly bonded OB, the god of lightning and dissection, to himself, and EB, the god of Frost and Destruction, to the protagonist. All he needs to do is capture the protagonist, and he pretty much wins. He knows that the protagonist has a lightning sprite that can absorb his electrical attacks to become stronger, but considers it to be a non-factor because sprites are easily banished. He also knows that EB's creations will obey her, but isn't worried because he has a small army of Amalgams, and also knows that OB's creations can only function under OB's orders. However, he was completely unaware of several important facts: firstly, OB's creations had a small degree of autonomy, and had built a clone of OB to guide them; Tristan didn't know about this because Fake!OB was non-functional, but the protagonist managed to get it operational. In return, Fake!OB sent OB's creations against Tristan for the final battle, and also gave the protagonist's lightning sprite a warding that made it impossible for Tristan to banish. lastly, it gave her a means to communicate with the imprisoned Real!OB. Tristan's reaction to this is absolutely priceless. More importantly however, Tristan is unaware that there was a complication during EB's bonding. At the start of the story, "Spirit Guides" (Actually the readers, who give the protagonist suggestions on what to do) were bonded to the protagonist, occupying the place where EB was supposed to go, meaning that EB is actually bound to the readers, instead of the protagonist. Since we can sever our connection with the protagonist at any time, the readers are essentially provided with a big red button labeled "Screw Tristan's plans six ways to Sunday." And Tristan certainly couldn't have predicted the readers using this information to prove to the original OB that Tristan's plan couldn't work, and that this would cause OB to take advantage of Tristan's unstable mental state when he tried to go One-Winged Angel to leave his body.
In The Salvation War, this is the downfall of several figures in the story, not least of which include the antagonists Satan and Yahweh, while in contrast much of human military tech shown in the story is concerned with trying to prevent this. In particular, Generalof the ArmiesDavid Petraeus is shown on several occasions accounting for known unknowns.
Despite all of the completely ludicrous things they managed to pull off in Dr. Horrible, I still don't think anybody was expecting Bad Horse to be an actual horse.
In the "40K Rejects" series by Mini War Gaming dot com, in Episode 3 (The Tale of an Ork), Captain Slaughter and co. are looking for the five Ork Shokk Attack Guns. They capture several Orks in combat, and Slaughter interrogates them one by one. The first few are gibbering idiots, but the third is quite articulate. His intelligence and knowledge intrigue Slaughter, who is subsequently shocked to discover that the Ork is actually "the Warboss in disguise"!. Slaughter's reaction to it is priceless:
Slaughter: Out of all the unforeseen things I've ever seen!
Ranger has multiple times fallen victim to the first type in Comic Fury Werewolf. He's several times forgotten key facts which are public information due to focusing too hard on the details. One of the worst is how he's twice forgotten about the vigilantes, and even forgot about the alpha's ability to convert until he was dead and too late to warn the village.
In Twitch Plays Pokémon Red, the Mob came up with a cunning plan to make sure that Bird Jesus didn't get released or deposited when they went to the PC. If they fainted everyone in the party except for Bird Jesus, he couldn't be put in the PC because then Red would have no usable Pokemon, right? As it should so happen, this leads to variety five - in the first generation of Pokemon, you can deposit the only Pokemon in your party... leading to Red managing to black out inside a Pokemon Centre!
In an episode of Superman: The Animated Series, Brainiac is surprised when he blasts off Batman's suit and Superman is underneath it, having taken on the guise of Batman with Bruce Wayne having gone missing (due to Brainiac kidnapping and brainwashing him for his plans). His reaction is typically understated...
Brainiac: "Kal-El! ...This occurrence was highly improbable."
Lex Luthor: Did you really think you could take me all by yourself?
Amanda Waller: Actually, yeah. But on the off chance I might've been wrong...
[The founding Leaguers have entered through the window]
Which is immediately followed by another one: It turns out that Brainiac is underneath Lex's suit. And skin. I guess he learned his lesson...
Then, of course, there was the episode "Wild Cards." In the middle of Joker's bomb threat on Vegas being aired as a reality TV show, Batman manages to talk to Harley Quinn alone. He insinuates that Joker seems awfully close to Ace, the new henchgirl. Harley storms off toward her puddin' in a jealous rage, but not before throwing and landing a solid punch on Batman for enlightening her. Cue to a shot of Joker staring blankly at a television screen after the exchange is over.
Joker: Have to admit, I didn't see that one coming...
Fire Lord Ozai faces a couple in the last episode: an Unknown Known Aang regaining control of the Avatar State and then and Unknown Unknown Energy Bending.
Korra has a habit of landing in the middle of #3. Because she has no information on her enemy (and very few means of getting it), every episode or two, her enemies pull out something she didn't know about and proceed to hit her with The Worf Effect. The most brutal example was when Tarrlok turned out to be not only a bloodbender, but able to bloodbend under any moon phase, something established to be impossible in the original series.
The episode "Homie the Clown" has Homer unable to get the thought of Krusty's Clown College out of his head, even imitating the mashed potato scene from Close Encounters of the Third Kind (except he sculpts a circus tent) and seeing his family in clown makeup and waving ads. Eventually he stands up and declares "I'm tired of you people holding me back! I'm going to clown college!" Bart simply remarks, "I don't think any of us expected him to say that."
Invoked in the episode "Bart's Friend Falls in Love" where Bart and Milhouse get into a giant fight. Groping around for a weapon, Bart finds Milhouse's new Magic 8-Ball and clocks him upside the head with it. As he looks at the shattered hunk of plastic in his hand, Bart remarks "I bet [it] didn't see that coming."
In an episode of ThunderCats, Mumm-Ra and the evil Mutants had succeeded in capturing ALL the Thundercats - except Snarf. When the Mutants discuss whether they should get him too, they all laugh at the notion that little, dorky Snarf could in any way possibly affect their plans now that they've essentially won. Little did they realize Snarf's talent for communicating with animals, as well as being so small and weak to be ignored to begin with, turned out to be their undoing.
It was almost a Running Gag in Kim Possible how many bad guys would have Kim and/or Ron absolutely nailed to the wall, fail to account for Rufus chewing through their bonds or hitting the self-destruct for the Kill Sat, and then are absolutely stunned that their plans were foiled in the end. And they usually never learned otherwise no matter how many times it happened to the same villains. In an early episode Drakken did manage to spot Rufus in time to foil him (because a mind controlled Kim pointed it out) but he winds up underestimating Kim's brothers instead when he doesn't believe they have a portable version of a device that (as seen earlier in the episode) is normally the size of a refrigerator.
And then the villains in the Grand Finale face an awesome Unknown Unknown in the form of Ron's Mystical Monkey Power.
Applejack says this in "Swarm of the Century", when the voracious parasprites, instead of eating her apple crop, ate her barn instead.
The two things that Discord hadn't planned for were Celestia breaking Twilight out of her Heroic BSOD by sending her the letters her student had sent her the entire previous season and Twilight somehow reuniting her friends and breaking them out of Discord's Mind Rape so they could use the Elements Of Harmony to defeat him. The former is likely an Unknown Unknown he couldn't have expected and the latter is a Known Unknown: he knew about who was involved but hadn't foreseen how they could do anything to stop him at that point.
After Chrysalis's true form was revealed in front of Celestia and her plans explained, it was obvious that Celestia wasn't going to stay still about it. What wasn't obvious was that the queen of the Changelings had already gathered enough strength to beat the Princess. Not even Chrysalis expected that!
Done heartbreakingly so in Twilight's Kingdom Part 2 when Discord turns against the other ponies and captures the Mane Six (save for Twilight). Discord mentions that they should have seen it coming, only for a heartbroken Fluttershy to admit she hadn't at all — she was so convinced her friendship with him was ironclad, she never thought he'd turn his back on her. This turns into an Ironic Echo when Discord himself is betrayed by Lord Tirek and Applejack tells him the same exact thing.
Discussed by Edward's friend (voiced by Samuel Jackson) in The Boondocks. He talks about how there are known unknowns, things that we know that we don't know, and unknown unknowns, namely things that we don't know that didn't know, in order to justify how the plan that they had to capture a killer was so far going badly.
In the second to last episode of Teen Titans, during the Final BattleJinxswitches sides. Cyborg comments "I didn't see that coming". Control Freak nods in agreement while being pinned down by Cyborg.
In an episode of King of the Hill, Connie runs into the house sobbing and says that Bobby broke up with hernote Only not really, it's a ruse. Kahn's immediate response is "Wow, you just taught me the meaning of 'total surprise'."
In an episode of Foster's Home for Imaginary Friends has Bloo running against Mr. Herriman for the position of governing the house. This happens in response to Bloo's slander of simply saying "Herriman smalls like poo!".
In the Ed, Edd n Eddy episode, Boom Boom Out Goes the Ed, Ed says this after Eddy throw the TV Set at him for can realizing there’s a blackout.
Junior, intent on embarrassing Ted who hadn't brought back The Lost Shrine of Zagawa, is stunned (along with everyone else at the press conference) when George knocks down a dinosaur skeleton. "Wow. I didn't see that coming."
In the final story arc of Once Upon a Time... Space, both the Humanoids and the combined fleet of the Confederation of Omega were completely caught by surprise when The Precursors decided to show up and made a star go nova right as the Humanoid armada passed by. Goes close to Ass Pull, except one of the Precursors appeared saltuarily during the series to comfort Psi when she was in trouble, and the ship that shows in the final episode had already appeared in the first one and showed their technological superiority.
The submarine USS San Francisco once ran smack into an Underwater MOUNTAIN. Apparently, the captain and crew should have seen that coming if they were doing their jobs right (the captain ended up relieved of duty). So that would make this a case of unknown knowns.
During World War I, the Austro-Hungarian battleship SMS (Seiner Majestät Schiff) Szent István, which translates as "His Majesty's Ship Saint Stephen", was torpedoed and sunk by two Italian motor torpedo boats that just happened to pass in the area. This goes under the Unknown Knowns category, as the Austro-Hungarians knew that the Italians used motor torpedo boats and considered them a threat due their tendency to attack their fleet in the harbours. They just didn't expect them to be able to torpedo a battleship in the middle of the sea in spite of a destroyer and torpedo boat screen (and in fact thought it had been submarines until the Italians started bragging).
The Italians tended to be involved in this during the war. When they declared neutrality in 1914 they caught everyone by surprise, as Italy was in a military alliance with Austria-Hungary and Germany at the time. Only, it covered defensive wars, and technically Austria-Hungary attacked first. Falls into False Assumptions, as everyone had thought Italy and Austria-Hungary had managed to put aside their border dispute (Italy hadn't).
In 1916 the Italians were completely caught by surprise by the Austro-Hungarians attacking: doing some math they had figured the enemy didn't have the manpower to fight Russia on one front and mount an offensive on the other, and the Austro-Hungarian nearly broke through. Then the Austro-Hungarians were caught on the receiving end of this: the Russians attacked en-masse, forcing them to move all the attacking troops on the other side of the country. Both falls into Unknowns Known: the Italians had noticed the massing of troops but dismissed it, and the Austrians should have seen the Russian attacking that fast.
Italian artillery was another False Assumption: given the state of Italian industry, everyone expected the Italians to be unable to produce a lot of guns, only for them to field the second largest artillery park of any power in the war, to the Austro-Hungarians' growing horror.
The Battle of Caporetto contained a few of these. First the Austro-Hungarians and Germans broke through due the Unknown Known of the new German tactics and the False Assumption gas didn't work in high mountain, helping the breakthrough. Then the Austro-Hungarians ran into the Unknowns Unknown of the multiple reserve defensive lines that Cadorna and some of his subordinates had passed the previous year predisposing just in case: while a Modern Major General wasted an artillery trap that could have annihilated a prong of the assault and the Italians (whose army had almost completely dissolved under the pressure of the enemy attack and the low morale, with many soldiers deciding they would just return home) didn't get to the Tagliamento river in time to stop the enemy, by the Piave river the Italian soldiers had decided that the invader was to be defeated, reformed the army and held the line, and on the north the Austro-Hungarians discovered that a good chunk of the immense Italian artillery park had been placed on a mountain they couldn't cut off from supplies.
1918 has the Battle of Vittorio Veneto, a massive case False Assumption. By that point everyone had figured that the Allies would win the war, and the plan was for Austria to negotiate peace and Germany to fight through the winter to get better peace conditions. Then the Italians surprised everyone (including their own allies) by launching a sudden and massive offensive that they weren't supposed to have the morale and will for. Thanks to this and the Italian artillery being brought Up to Eleven, when the Italians were finished the Austro-Hungarian army had been annihilated as a coherent force and was running, the Austro-Hungarian Empire had barely managed to surrender unconditionally before collapsing, and Germany had to beg for peace before the Italians marched through Austria to attack them from the south.
Finally, the very last of the war: by the time the armistice on the Italian front took effect and the Austro-Hungarian Empire had started collapsing, the Austro-Hungarian Army hadreformed as a coherent fighting force. This falls under False Assumptions, as everybody had assumed that no army could do this... In spite of the Italian Army doing almost the very same thing exactly a year before. The Italian high command was very happy that the armistice had taken effect as the Austro-Hungarian Army proved they had outlasted the empire they served and laid down their arms (not surrendered) a regiment or division at time.
Overlapping with Unknown Knowns and False Assumption, the sinking of the Titanic has this trope written all over it.
Technically untrue with regards to the intelligence services. It wasn't so much that 9/11 was unexpected, at least by counter-terrorism professionals - between them, the CIA and FBI had enough intel to sweep the attackers up, but for "the Wall", a bureaucratic device that limited cooperation between the two agencies - Mohammed Atta even put the actual name of his hotel on his landing card! It is just that the attack happened before people expected it to, so more a case of Known Unknown. Of course, the US public was totally blindsided.
Related: US Secretary of Defense Donald Rumsfeld's attempt to explain the "Unknown Unknowns" concept at a wartime press conference was widely mocked by the ill-informed and malicious. Of course, as this was regarding the apparently absent WMD's in Iraq, the criticism may have been warranted. Those phrases became so strongly associated with Rumsfeld that he even named his published memoirs "Known and Unknown".
Mount Vesuvius was the first experience Roman civilization had with a full-fledged volcanic eruption. They had to invent a word to describe what happened.
The end of the era of isolation of Japan in the 19th century happened because of this: The Japanese assumed that no European superpower was going to waste their valuable resources in trying to invade Japan after the country isolated himself in the medieval era, since they would have to go around Africa just to avoid the Middle East (then one of the few ways to reach the Far East, and in that era, it was ruled by the Ottoman Empire) and by the time the Europeans could reach Japan, the Japanese could have enough time to fight back. The Tokugawa Shogunate didn't consider the American continent, as their knowledge of the world was limited to Europe and Asia, and since the United States didn't have to worry about dealing with Africa and the Middle East, instead traveling straight through the Pacific Ocean to Japan, it was too late for the Tokugawas when Commodore Matthew Perry forced the Japanese to open to the rest of the world.note It turns out the Americans (and by default, Perry) studied a lot about how Japanese culture works via the Dutch and previous Western contacts with Japan, and also by entering previously in Japan using Dutch flags, taking into account the Japanese could not distinguish between an American and a Dutch. Had the Japanese found out about this deception previously, the history could be different. This happened again in World War II when Japan attacked Pearl Harbor and didn't expect the U.S. and the rest of the world to fight against them to the death. This time, the result was even worse.
The whole rise of the Internet (the commercial one) can be considered one for the entire human race, as nobody considered how important the net was going to get in so few years, and many companies and even entire industries sunk thanks to, and also because of the Internet, to the extent that many governments and industries now seem hellbent on trying to tame it with mixed results.
All the Scandinavian countries were into this in 1814. In Norway, nobody expected the Treaty of Kiel, being handed over to Sweden without questioning. In Sweden and The British Empire, nobody dreamt of the Norwegians actually going as far as declaring independence, actively resisting a union with Sweden. The Norwegian Constituent Assembly made a drastic impact on every setup made in January 1814, changing the rules completely come November that year.
If you watch the video of the Army-McCarthy hearings, it is obvious that "Tailgunner Joe" is completely blindsided by Joseph N. Welch's "have you no sense of decency" speech. He can barely speak for a few moments.
The whole Ukraine crisis between Russia and the rest of the world was completely unexpected for everyone, since it reverted the situation to the Cold War-era levels and it's now causing LOTS of unexpected changes around the world.
In the "Wild West", an unarmed sheriff marched up to a very-much armed man and demanded he surrender his guns. The man laughed. The sheriff knocked him out with a punch to the face.
Two Subversions happened in Italy in 1970 with the Golpe Borghese. The Golpe's main armed component came from the Corpo Forestale dello Stato (the park rangers. To be fair, they have light infantry firepower) because nobody would expect it... Except the government not only knew of the attempted coup, they knew exactly who was trying it, and the army was fully mobilized and waiting for them. Also, the government expected the conspirators wouldn't see the government suppressing the coup and using it as excuse to declare martial laws, but their leader Junio Borghese found out and aborted the coup just in time.