You have a friend, who has never actually done whatever task you need to do, but hey, (s)he has read all about the subject so they are going to attempt it anyway. What could possibly go wrong... right?
This trope is the literary equivalent of I Know Mortal Kombat and Taught by Television — that is, the character in question gets their knowledge by reading about it. A character with only book knowledge of a subject may be the Closest Thing We Got in an emergency situation. Contrast Taught by Experience, where a person lacks formal knowledge but dives in headfirst into the thing to be learned.
- "I'm not a doctor, but I play one on TV."
- Similar to this is a hotel series, where someone steps up to a problem, is asked if they're an X, and replies "No, but I stayed at a Holiday Inn Express last night."
- Battle Royale uses this for two of Kazuo Kiriyama's Crowing Moments Of Awesome, both in Flashback. The first has him breaking the arms, nose, and jaw of a bunch of bullies, with the explanation that "I simply used the information I learned from this book" * shows a human anatomy text* . The second has a mean judo coach with a penchant for humiliating his students pick Kiriyama, reading a book in back, for the next spar. Kiriyama closes his book with the title facing the reader: "Introduction to Judo".
- When Gohan of Dragon Ball Z has to play baseball in high school, he notes that he has read about it after admitting that he never played it before. Of course, being a superhuman half-alien who spent a sizable portion of his life in Training from Hell, any physical activity is pretty much a cakewalk for him, once he understands what he's supposed to be doing.
- Eyeshield 21: The Amino Cyborgs team do only a middling amount of training, and spend more time getting juiced up and reading books on how to play football. This leaves them with low stamina and a poor grasp of football fundamentals when they play the Devil Bats.
- Yuu from Holyland first learnt boxing from a book. As this manga has a very realistic slant, he trained a lot before even thinking to use the most basic moves.
- In Noir, the Action Girl Kirika reads a book on making tea and henceforth enjoys it to no end. Which is kinda cute, once you consider that making tea is the only thing she can do well besides killing people, and the only thing she ever learned on her own.
- In Pokémon Adventures, the main reason Platinum went on her journey was to try out first hand the many things she read about. That said, sometimes she initially sucks at whatever she's trying out even when she recites whatever the book told her on the subject, like when she kept falling down when she was on a bike for the first time in her life.
- During sports day in Don't Become an Otaku, Shinozaki-san!, Kaede thinks she can play baseball after reading manga about it. She quickly gets beaned in the head by a fly ball.
- This was the shtick of the Golden Age DC Comics character Genius Jones (created by Alfred Bester). Jones was stranded on a desert island with 734 books. He read all of the books and memorised all of the information in them, before eventually setting fire to them to attract the attention of a passing ship. Once back in civilisation he sets himself up as the Answer Man, a costumed hero who answered questions and solved crimes for one dime, using the information he had gained from the books.
- Literally the power of the Marvel superhero called Gwenpool. Or at least one of them. She has read many of the comic books starring the characters she is now physically interacting with. She gains a momentary advantage over the current Thor by shouting out her real name.
- In A Delicate Balance, Twilight Sparkle's attempt to ask Applejack out is informed by copious amounts of How-To-Pick-Up-Girls style advice books. It goes about as well as one would expect.
- Twilight Sparkle finds out that this also applies to magical combat in Duel Nature.
- DJ Croft of Neon Exodus Evangelion is suspiciously good at sex, considering he's supposedly a virgin — he learned the how-to from a book and filled in the gaps with just-that-awesomeness.
- Ume from Sugar Plums uses this as an excuse for the skills she learned from her previous life. She's called out on it at least twice by another character, though the second time she actually throws a user manual at the character to explain that she did indeed read a book about what she was going to do.
- Aliens. Gorman's only been on two real drops. Counting this one.
- American Beauty. The 14-year old isn't the slut as she makes herself out to be.
- Anthony Hopkins plays a millionaire publisher in The Edge. He knows all about survival, but only from books, and finds himself having to put his theoretical knowledge to use when his plane crashes in the woods. It serves him surprisingly well.
- The climax of Executive Decision involves two of the protagonists having to land a Boeing 747 after the pilots are killed by terrorists. One of them has incomplete private pilot training, and they rely on the aircraft's manual to run through the process of landing the aircraft. Incidentally, such manuals being kept aboard planes is Truth in Television because modern aircraft are very complex, and experience has shown that forgetting a step either in flight or in maintenance can have disastrous consequences.
- In The Flight of the Phoenix (1965), one of the characters says he has experience building and designing aircraft. He later reveals he works with model aircraft, but it turns out the principles are much the same, just on a smaller scale.
- The Muppet Movie:
Kermit: Where did you learn to drive?Fozzie: I took a Correspondence Course.
- In the first Short Circuit movie, Number 5 reads everything in Stephanie's house (including the entire encyclopedia) before his adventures. The next day he reads the User's Manual (Not Driver's Training) for Stephanie's van immediately before driving it.
- The difference, for those who don't themselves drive, is the the User's Manual usually kept in a vehicle is information about things like how to check and add oil, how to operate the air conditioning, where the seat postion controls are located,etc - not the rules of the road, which vary from state to state and country to country.
- A subversion in that he's still an abysmal driver, and nearly gets himself and Stephanie killed several times within a span of a couple minutes. Since he only knew how the car was supposed to work, and not the rules of driving, it's still this trope.
- In Teenage Mutant Ninja Turtles (2014), given that the Hamato Yoshi backstory was adapted out for the Project Renaissance experiment, Splinter teaches ninjitsu from a book he found, instead of getting their Italian renaissance names from one. Shredder lampshades this during his fight that it might not be the best way to learn. Not that it stops him from actually putting up a good fight.
- In Three Days of the Condor, based on the novel Six Days of the Condor, Joe Turner's job for the CIA is to read books, newspapers, and magazines from around the world, looking for hidden meanings and new ideas. When the Call to Adventure comes to him, he uses his book learning to survive.
- In Train of Life, the driver of the locomotive had to teach himself from a book. Actually, it works.
- Julius Benedict in Twins knew all about driving from reading about it, and having read the car's manual, he knew he could shut off the alarm by lifting it up from the back, thereby tricking it into thinking it was being towed. Of course it only worked because of his extraordinary strength.
- In Those Magnificent Men in Their Flying Machines, Colonel Manfred von Holstein attempts to teach himself how to fly by reading the official German army handbook on piloting; while he is flying. He does surprisingly well until he drops the book.
- Horatio Hornblower is constantly reinforcing his Badass Bookworm status by reading. That and the fact that he is very Good with Numbers. The Midshipman stories in particular often have young Hornblower comparing his new, actual experiences of sailing and war to what he's read about in books.
- In Wintersmith, Roland believes that he will be an expert swordsman because he has read the fencing manuals and fought many imaginary swordfights in his mind.
- The Rupert in Monstrous Regiment does the same thing. He actually cuts his own hand practicing out of a book.
- His sword hand, in fact. Do not ask how.
- King Verence and Queen Magrat order a lot of text books, too. Misreading the word "martial" makes for all sorts of fun.
- Don Quixote is a very old example; he read tons of books about knights and then thought he could be one.
- Scriber Jaqueramaphan from A Fire Upon the Deep by Vernor Vinge; he also tends to be pretty incompetent in most of the things he's read about. Terrifying the hell out of his friend when they're about to sneak through the army of a feared warlord; Scriber is a spy, and is therefore assumed to have experience in this until he says:
"Don't worry. I've read all about doing this sort of thing!"
- Heinrich Dorfmann in The Flight Of The Phoenix instructs the survivors on how to rebuild the crashed plane... even though he's only ever designed model aeroplanes
- In Harry Potter, Dolores Umbridge states that just having a theoretical basis in Defense Against the Dark Arts should be enough to prepare the students to successfully take their exams. (In a subversion, though, the real reason for the dumbed-down, book-taught Defense Against the Dark Arts class is to ensure the students don't have any practical knowledge.)
- Hermione gets a few of these. Most of the time, it actually is enough.
- David from the novel version of Jumper when he finally loses his virginity. Millie asks if he's really a virgin, and he replies, "I told you, I read a lot." (It's a running gag, the "read a lot" thing).
- Masked Dog by Raymond Obstfeld. The villain is a convicted criminal used to test an experimental drug which gives him Super Strength and the ability to retain vast amounts of information. After using his skills to escape, he decides to become a master assassin, but while his new powers make him dangerous, his application is often flawed. For instance he reads a book on lockpicking, but when trying to pick a lock, he loses patience and just smashes down the door.
- Twilight's Edward Cullen. While the rest of his family was having housebreaking sex, he was by his lonesome spending his sleepless nights studying everything there is to study. For example, he cooks perfect meals for Bella on his first try, despite never having a reason to cook before.
- He often Lampshades this fact when he talks about human emotions like jealousy and lust.
- In The Day of the Triffids by John Wyndham, a character known only as "the radio man" learns to fly a helicopter by reading books and practicing for half an hour.
He seemed to have complete confidence that his instinct for mechanism would not let him down.
- Thoroughly averted in The Lay of Paul Twister. Paul is from modern-day America, and he's stranded in a Standard Fantasy Setting. He's read books about a lot of things, but he only has about as much understanding of how modern technology works as any modern person would pick up from Popcultural Osmosis. So when he wants to get something new invented, he has to get some researchers and engineers who actually know what they're doing and point them in the right direction.
- In the All in the Family episode "Edith Writes a Song," Mike tries to placate two African American burglars whom Archie has racially insulted, by explaining that Archie doesn't know what it's like to grow up in the inner city. One of the burglars responds, "Oh, and you do?" Mike sheepishly replies that he learned about it in his sociology course.
- On The Big Bang Theory, Sheldon Cooper attempted to learn to swim on the internet. And to rock climb.
- He's actually pretty good at the climbing. It's when he looks down that it all goes wrong. (He's afraid of heights).
- He also tries to find a book on how to make friends. All he can find is a children's book, Stu the Cockatoo is New at the Zoo, but he figures he can extrapolate the skills to fit his needs.
- Invoked unsuccessfully in A Bit of Fry and Laurie when they try to fly a plane with no experience, not even reading about it.
- Hugh: Right now, Sir Peter, you've never flown an aeroplane before?Stephen: Never flown in my life, Johnny, no.Hugh: And you've never had any lessons?Stephen: Oh I've had lessons, maths, geography ...Hugh: But not in flying?Stephen: No.Hugh: And I've never flown before. Is this something you've always wanted to do?Stephen: Not particularly. So when you rang up I just leapt at the chance.Hugh: Right.
- In Buffy the Vampire Slayer, Wesley bragged that in the new Watcher training, he had even taken on two vampires "under controlled circumstances, of course". Giles quickly countered that he wouldn't encounter those in Sunnydale... controlled circumstances, that is.
- Manuel in Fawlty Towers. "I speak English well. I learn it from a book."
- Parodied with Dave in Flight of the Conchords, who acts like an expert in all things, especially being a ladies' man. Judging by his tendency toward malapropisms and the way he (deniedly) lives with his parents...
Jemaine: You'd better watch out. Bret knows karate.
- Also taken to a logical extreme:
Bret: Yeah, I've got a book on karate. But I haven't actually read it yet.
- New Tricks: Dan Griffin is widely read and has a lot of esoteric knowledge. But this trope really comes into play when he demonstrates mad skills at five-a-side football despite never having seen a match. He explains that when he learned they were going to be playing, he read several books on the subjects and the rest was "basic physics". However, he does fall for an obvious feint, because he has no way of knowing what one is.
- Star Trek: Voyager, "Rise." When trying too hard to impress Tuvok, Neelix claims to know everything about orbital tethers (flexible columns going from a planet to an orbiting station, so you can take a Space Elevator to it). Tuvok is not impressed when Neelix eventually admits that he really only worked with models. Very detailed models as he's quick to claim, but still models. The practical knowledge he has is more than everyone else's put together, though—and it's enough to avert disaster.
- The X-Files: "I play Dungeons & Dragons. I know a thing or two about courage"
- Read About Love by Richard Thompson would be an inversion: the character portrayed has "read about love" and doesn't understand why he makes girls cry.
- Figures into the plot of "Counting Out Time" from the Genesis album The Lamb Lies Down on Broadway. The main protagonist, Rael, has read a book about erogenous zones, and he thinks that's all he needs to get his date to sleep with him. However, all he ends up getting is a slap.
- The Factotum class (dungeonscape) in Dungeons & Dragons has this as it's premise. As a result its class skills are "All", even obscure class specific ones are treated as class skills for a factotum.
- This is actually a knack in Scion. Basically means that the Scion has read so much about stuff they can try them even if they have no training.
- Pretty much any CRPG will contain skill books for those all important extra skill points.
- In Dragon Ball Online, Gohan writes a book called "Groundbreaking Science," which explains the concepts of ki control, helping saiyan hybrids to learn how to fly/shoot ki blasts/etc by reading a book.
- A guard in Paris in Girl Genius seems to think that having read about Reverents will prepare him for a fight with a large group that's surfaced in Paris. An older veteran disagrees saying there's nothing which could prepare the uninitiated.
- Parodied in Family Guy:
Peter: It'll be okay Brian, I read a book about it.Brian: Are you sure it was a book? Are you sure it wasn't...nothing?Peter: Oh yeah.
- My Little Pony: Friendship Is Magic, "Fall Weather Friends": Grade-A bookworm Twilight Sparkle enters a big marathon, the Running of the Leaves, alongside her more athletic friends Applejack and Rainbow Dash. The two of them scoff when Twilight claims she's read a book on running techniques in preparation for the race, but in the end she manages a respectable fifth place for a first time race by pacing herself, while Applejack and Rainbow Dash end up tied for dead last because the two of them were too preoccupied with making sure the other doesn't win.
- This is a large part of Twilight's personality (A common Fan Nickname is 'Purplesmart Bookhorse'). Between Super OCD, checklists to track checking her checklists, and apparent access to L-Space to be able to find a book on anything anywhere. She had a how-to book on slumber parties, in an episode about them, for example.
- Ted from Daria turns out to be good at a VR game because he read manuscripts on swordplay. It's almost the inverse of I Know Mortal Kombat.
- In one episode of TaleSpin, Baloo's pilot's license is suspended, so Rebecca keeps the business going by teaching herself to fly the Sea Duck from a book.
- Steven Universe: Peridot has only read up on a few hundred years worth of gem history reports on Earth (Gems as a species can be so old that the younger ones can fall under Time Abyss). Despite this, she didn't know there were still gems on the Earth other than The Cluster and its prototypes.
- The entire reason for the Dummies (Wiley), Complete Idiot's Guide (Alpha Books), Teach Yourself (Hodder & Stoughton), and Everything Guide (Adams Media) series' success, as well as websites like eHow and Howcast. Don't underestimate the value of practice though — "instinct" isn't.
- There was a parable in the Eighteenth century about the need for this in a military officer and the fact that street smarts isn't necessarily enough. It goes roughly like this, "There was a mule who served in the army for ten campaigns. At the end it was-a mule."
- But mules don't learn military tactics by experience on the battlefield; people do.
- For the matter of that, the mule probably did learn how to carry stuff around which is of course what mules are for.
- But mules don't learn military tactics by experience on the battlefield; people do.
- Subversion. According to C. S. Lewis in The Discarded Image (a series of lectures about the cultural background of Medieval literature) many medieval beliefs, even those that sound like holdovers from primeval superstition were in fact simply because somebody had read a book about them. Books were so expensive and such fine pieces of craftsmanship that no one could really quite make themselves believe that a book could actually be wrong.
- Among the many lesser-known things the U.S. government habitually does is pay for the creation of (often mind-numbingly) detailed publications and manuals on pretty much any random thing a citizen might need to know how to do. For example, cooking a turkey or safely cutting down an evergreen tree with a chainsaw. Said publications are cheaply (cost of printing and postage) or freely available, especially with the rise of the Internet, and there have been accounts of people (usually in the bureaucracy, who know about them and can find given topics) who learn skills mainly from these.