Faked Rip Van Winkle

The hero is rendered unconscious and wakes up in an unknown place.

Seemingly benevolent people appear and claim that the hero has been unconscious for many years, sometimes decades. To back that claim up, the hero is presented various evidence like future dated newspapers, futuristic looking appliances, and even people who say they are older versions of individuals the hero knows.

Although he may initially be fooled, the hero either figures out that this is all an elaborate charade to take advantage of him, or an innocent discovers the situation and is taken hostage. In addition, the hero's friends may find him and expose the scam.

In the end, there is often a big battle as the hero tears the trickery down. Once he returns home, he may be relieved that everything is back to normal or he may harbor feelings about the very tempting world-that-could-have-been he was trapped inside.

There's also a lighter version where there's no elaborate hoax (and no harm done or attempted), just a prank that's quickly exposed with either a "just kidding" on the part of the perpetrator, or a "stop messing with him" from some third party.

See also Rip Van Winkle (duh). Compare Lotus Eater Machine.

Examples of Faked Rip Van Winkle include:

Anime and Manga

This is the plot of an episode of Science Ninja Team Gatchaman/Battle of the Planets, used to get the main hero to give the baddies some important information.
Elemental Gelade: the female lead is led to believe that she was sealed away (for the second time) for decades and everyone she knew has passed away. Rather than gathering any information, it's supposed to discourage her from leaving the facility and putting herself in danger, since she's part of a protected species of super weapons.
Kurama and Kuwabara do a weak version of this in Yu Yu Hakusho when Yusuke wakes up after the Four Beasts arc, briefly allowing him to believe Keiko died before he could smash the bug-whistle or while he was unconscious, and that this was discovered in the interim while they brought him out of Maze Castle and put him in Kuwabara's spare room. Just because they're dicks. Let it never be said that Kurama is always a serious or sensitive person.
Taken to extreme in Blood C. And poor Saya isn't a hero either, she's more akin to a monster.

Comic Books

This is the plot for a short Monica's Gang comic. Monica is told about the story of Rip Van Winkle, and after she falls asleep under a tree, the boys set up everything to make it seem as if many years have passed. She is fooled for a while (she's 6, after all), but finally figures out the plot when she sees Maggie, who wasn't in on the story and acts completely normal.
A story in Panini Comic's Batman and Superman magazine features this where Superman flies back to Metropolis and is engulfed in a white vortex. He finds himself in a now-ruined Metropolis and finds Jimmy, who tells him he was responsible for destroying Metropolis. It turns out really that Lex Luthor captured Superman by putting him into a simulation tank.
Huey, Dewey, and Louie pull one of these on Donald Duck in an old CarlBarks story, as part of a Zany Scheme to get out of a tropical vacation. It works.
An early post Byrne reboot story had Superman returning to Earth to learn that he was regarded as a monster, Lois was crippled because of him and eventually he starts to lose control becoming more violent and horrified at his own actions. It turns out, the whole scenario is a nightmare triggered inadvertently by telepathic contact with a crystalline alien entity who was trapped on the moon. The nightmare was the manifestation of Superman's worst fear, that he would lose control of himself or his powers and cause untold death and destruction. This fear has been a recurring theme for the character ever since.
The Ultimates: When Captain America first wakes up in the modern era in issue #3, he thinks this trope has happened to him due to the "colored" general (Nick Fury) standing in the room telling him 60 years have passed (Fury here is black and Cap met the highest ranking black person of his time, a captain), and immediately starts beating the crap out of everyone in sight. Justified in that he was fighting Shapeshifting technologically advanced aliens before he was frozen.
- In fact he was fighting them when he was frozen.

Film

The 1965 film 36 Hours, in which German agents use a Faked Rip Van Winkle on an American officer in an attempt to learn the details of the upcoming D-Day operation. It invented or popularised several common features including the "memory therapy" which is really a disguised intelligence debriefing, and the hero's realisation that he still has a minor injury that ought to have healed if so much time has really passed.
The 1990 Captain America movie had the Captain suspect an inversion of this when he notices that the Intrepid Reporter explaining things to him was driving a German car with a Japanese radio.
- Likewise, in the 2011 version, Cap suspects an inversion is happening when he comes to in a hospital room with a Mets game "broadcast live" on the radio - one he attended in person.

Folklore

Older Than Print: An old Japanese story tells of a daimyo and his bodyguard who stop at an inn run by a six-fingered young woman and her brother. They sleep there overnight, only to be greeted in the morning by a six-fingered old woman and her "grandson", who inform them the spirits have drawn them into the future. The old woman tells them she can send them back, but requires money to fund the ritual needed. Before the daimyo can send a message for the funds, however, his bodyguard works out that they're still in the present day—the nearby bamboo has grown only as much as one would expect it to in one day. The old woman was the young woman's grandmother—six-fingered hands run in the family (or, in some versions of the story, the girl simply used make-up).

Live-Action TV

Mission: Impossible: The IMF used this plot several times. Sometimes combined with a Fauxtastic Voyage, as a common excuse for the extended sleep was that the mark had been in an accident.
- "Invasion". A spy who had revealed details of holes in the US radar net was persuaded that he had been unconscious for several days, the invasion had succeeded, and he would be executed as an enemy agent unless he could prove his part in it.
- "Two Thousand". That same season, they conned a man into thinking a nuclear war had hit and he'd been in a coma for 28 years, and that the only way he could avoid execution was to reveal where he'd hidden a stolen cache of plutonium.
- "Operation Rogosh". When an enemy agent plans a biological attack on Los Angeles, the IMF must trick him into revealing the type and location of his devices. They convince him that it is three years into the future, that he is back in his own country, and that he is on trial for being an American spy.
- One time, they did it twice at the same time, a con within a con: They first faked a "futuristic" future, then let the suspected crook "discover" that he had only "slept" just long enough for the statute of limitations to run out, whereupon he went to his cache of loot.
- And they once convinced a retired gangster that he had dreamed the previous thirty or so years and he was back in the 30s as a young man.
F/X: The Series also faked one on a villain to coax him into revealing the location of a bomb the villain had planted.
- Also done in reverse when an imprisoned assassin develops a brain tumor that is causing him to lose his memories of the last few decades. He still vaguely remembers the time when he killed a US senator so the team takes him back to the small town where it happens and stages things to look like the day before the assassination and make him think that he dreamed of the killing and still has to complete the job. They do this so he is tricked into revealing the identity of the Big Bad who hired him to kill the senator. The assassin's deteriorating mental state makes him very confused and gullible and he does not figure this out till the Big Bad tells him.
Done to SG-1 in the Stargate SG-1 Season 2 finale "Out of Mind" by the Go'auld Hathor.
Star Trek: The Next Generation: "Future Imperfect" has Riker wake up to be told that he was recovering from an amnesia-inducing sickness some twenty years in his own future. The twist here was that the conspiracy was not, as it first seemed, an evil Romulan plot to find strategic information, but rather a lonely alien child who wanted someone to play with.
Inverted in the Star Trek: Enterprise episode "Stratagem". Captain Archer tries to get information out of an alien by convincing him that they are now friends and that years have gone by. The alien ship they have supposedly stolen is actually set up inside a small shuttle in the Enterprise landing bay. The small touches making the simulation seem real include tattooing both their arms with prison barcodes.
- Captain Archer suspects this trope in "Twilight"—unfortunately he really is in a Bad Future.
Done in reverse on Adam Adamant Lives in the Missing Episode "A Slight Case of Reincarnation". The villains try to convince Adam, a Human Popsicle, that he's back in 1902 and that his adventures in the 1960s have been a dream. They force his friends to play bit parts in this scheme under false identities, and even bring in a lookalike for his 1902 girlfriend. The telltale clue that it's a setup comes when he mentions Harold Wilson, the 1966 Prime Minister, and is told that he must be thinking of Woodrow Wilson. This is a slip because in 1902 Woodrow Wilson hadn't gone into politics yet.
Also tried on Buck Rogers in the 1950s series.
It's only a few months, but this is done to Stringfellow Hawke in the episode "Echoes from the Past" of Airwolf. A fake news story is created -- involving the divorce of Charles and Diana.
Another small-scale version turns up on the 1990 Zorro remake, wherein the entire pueblo, led by Don Diego, works to buy time for an unjustly accused man by pretending that the Alcalde's been delirious for a week and the hanging's already happened. That this elaborate scheme is unravelled by the Alcalde noticing that a recent wine stain on his carpet hasn't dried yet does not speak well of Diego's scheming ability (especially since he-as-Zorro caused the stain in the first place).
Hardy Boys-Nancy Drew Mysteries: "Sole Survivor", where Joe wakes up in a hospital room with no clue where he is or how he got there, only to be told that he's not only been in a coma for a year, but that his father and brother are dead. Cue fake newspapers, fake newscasts, and forged letters from all his surviving relatives and friends. Of course, Frank and Fenton are very much alive, and the whole thing is a Mind Screw to get Joe to reveal information on a defection attempt.
The Six Million Dollar Man is led to believe he was somehow put in a suspended animation chamber, and several thousand years have gone by. He's outside at night with one of the people involved in the plot, and he knows astronomy; the stars should have moved for it to be as far forward in the future as they claim.
Also reversed in an episode of Alias, where, in order to obtain vital information, Jack Bristow is made to think he is back in the 1980s. Sydney plays her mother (and his then-wife, before she turned out to be a Deep-Cover Agent), then has a Squick feeling when he attempts to get frisky with her- as he thinks she's his wife.
The 2004 Battlestar Galactica: Although not a strict version of this trope (as little time has passed), the episode "The Farm" when Starbuck is injured during an ambush, and wakes up in what she is told is a resistance hospital, is definitely in the same spirit. This was acknowledged in the podcast; the writers therefore played along with the audience's suspicions by making Starbuck equally skeptical, but too weak from her injuries to do much about it.
An episode of the 1970s Hardy Boys TV series had the bad guys do this to one of the boys. They dyed his hair to make him look older, but he caught on when a shirt that had supposedly been hanging in his closet for 10 years still smelled of his girlfriend's perfume.
In Doctor Who in "Invasion of the Dinosaurs", Sarah Jane is knocked out and then told she is on a spaceship which has been travelling for months to a new world. She realizes this is not true because she still has a fresh bump on her head.
In a short-term heroic variant, the team on Criminal Minds used clock-shifting and a fake news broadcast to get a captured terrorist to think his co-conspirators had already unleashed a WMD, so he'd boast about it and reveal the intended target.
In The Wayne Manifesto, Wayne's family pulls this on him to make him believe he's slept through Christmas and that it's the first day of school.
One clip on America's Funniest Home Videos had a twelve-year-old boy so tired from his first day of the seventh grade he came home from school and fell asleep. When he woke up at nine that evening, his dad tricked him into thinking it was the next day and he was going to be late for school. They were already driving before the kid learned from a neighbour it was all a prank.

Toys

In Bionicle, Sahmad is put into a Lotus Eater Machine where people claim he has been asleep for 750 years.

Web Comics

Happens very, very briefly in this Order of the Stick strip.
A similar example occurs in this Questionable Content strip.
And less briefly in Kevin and Kell. It starts here.
Sluggy Freelance used this for comic relief. Torg was nearly killed when the demon K'z'k showed up unexpectedly, and he was unconscious for the entirety of a long fight. His friends decided that in addition to filling him in on the details of the battle once he woke up, it'd be nice to break the tension by convincing Torg he had been in a coma for five years.

Torg: "'Hey, our friend is in a coma, let's freak him out if-and-when he comes to!' What's wrong with you people?"

Ctrl+Alt+Del: Ethan builds a "time machine". "Time machine" explodes. Roommates pretend to be in the future as a prank, 'cause Ethan's kind of a dick.
- Immediately inverted when it appears that the time machine actually did work, and a future version of Ethan contacts him with a "dire warning". He ignores... Err... Himself? assuming it's another prank.
This Brawl in the Family strip. "Now maybe you'll think TWICE about eating one of us!"
Ellen in El Goonish Shive wakes up after dreaming the first six years of memories of her alternate universe counterpart, and is momentarily scared that she slept through six years. (Elliot's "you're finally awake" comment doesn't help.)

Western Animation

An episode of G.I. Joe, "There's No Place Like Springfield," thrust Shipwreck into the future where he was happily living a life of civilian retirement with Cobra long defeated. He can't remember any of the apparent past 20 years and seeks out medical help. Turns out, he's not in the future, it's all an elaborate setup by Cobra, and the "treatment" he's receiving for his amnesia is actually an attempt by Cobra to get him to reveal the plans for a chemical-based superweapon.
DuckTales: Huey, Dewey, and Louie try this on the small-scale, convincing their Uncle Scrooge that he's slept through Friday in order to get their allowances before the end of a big sale. Unfortunately, when Scrooge McDuck thinks it's Saturday, the whole world must follow suit.
- This was used as a Recycled Script in another Disney Afternoon show, Tale Spin. Baloo bumps Becky's calendar ahead a day so she'll think it's Saturday and he won't have to work. (He also gets a radio show host to play along with the deception, running the Saturday show on Friday morning.) Thanks to Finagle's Law, the consequences of the prank spin out of control quickly with the end result that Becky almost ends up shot by a Thembrian firing squad made up of tanks.
Gargoyles: In the 2nd-season episode "Future Tense," Goliath finally returns to Manhattan, only to find that the repeated journeys to and from Avalon have taken 40 years of time in the "real world," and Xanatos has become an immortal tyrant in the meantime. He's conquered New York and turned it into a dystopia. The entire thing turns out to be an illusion created by Puck in an elaborate con to get Goliath to give him the Phoenix Gate.
This happens in the Futurama episode "A Fishful of Dollars" - in reverse. After being drugged, Fry awakens in a shoddily constructed pizzeria set, where "employees" have him convinced that he is back in the year 2000 in an attempt to get Fry's PIN number. Given Fry's ~~guileless~~ brainless nature, it works.
- Happens unintentionally in "The Cryonic Woman". Fry and his old girlfriend freeze themselves to go to the year 4000, and when they wake up in a deserted wasteland they assume civilization has collapsed. Only later do they find out that they were really only frozen for a week or two, and civilization is doing just fine. The wasteland is actually contemporary Los Angeles.
Happens in the animated series Buzz Lightyear of Star Command when Buzz is captured by Zurg and made to think he's in a museum hundreds of years later. Zerg plays him by having the "museum" get all manner of details hideously wrong, including his catch phrase (properly "To infinity and beyond!"), so of course he starts fixing details and soon is telling little kids stories about how he defeated Zurg on this or that occasion and how Star Command's weapons and security work. He only realizes the truth when he finds out that the museum's "copy" of his laser-equipped suit is the real thing (the laser destroys part of the set).
Played with in one episode of The Simpsons. Jasper uses the Kwik-E-Mart's freezer to cryogenically freeze himself so that he can see the wonders of the future. At the end of the episode, he thaws out (much to the chagrin of Apu, who was making huge business out of displaying him like some sort of freak show) and mistakenly thinks he is in the far future. ("Moon Pies.... what a time to be alive.")
- Minor example from the episode where Marge discovers the internet: she stays on the computer all night, and in the morning, Bart lies about the day, saying it's Saturday (it's a weekday, probably Friday or so).
An episode of the Diabolik animated series had Eva and Diabolik pulling this on an enemy of theirs after the latter two were involved in an accident which left the enemy unconscious. Part of the act had Diabolik pretending to have been rendered quadriplegic and catatonic after the accident so that the enemy would start taunting him with the information he was after.
In Dan Vs. "The Fancy Restaurant", Dan is knocked unconscious and wakes up in a dungeon. When he asks what happened to him, one of the other prisoners tells him he's been in a coma for twelve years, but another prisoner informs him that it's only been ten minutes.