Like Reality Unless Noted

""Robert Heinlein once wrote that the best way to give the flavor of the future is to drop in, without warning, some strange detail. He gives as an example, 'The door dilated open.' Mention it once, and never mention it again, except to satisfy the needs of continuity. And your readers know, from these subtle details, that they aren't exactly dealing with the real world anymore."

- Larry Niven, in his essay "Building The Mote in God's Eye"

The general assumption that all of the unstated details of the setting of a work of fiction that remotely resembles Real Life can be filled in by the audience's knowledge of the world in which they live, except in areas where the fictional world explicitly or by necessary implication deviates from Real Life.

So, for example, if the characters note that they've just gotten back from Paris, the audience can safely assume that this is the capital city of France complete with Eiffel Tower, even if this is never made explicit in the narrative. If a character mentions reading War and Peace, then even without further details, it can be assumed to be the lengthy Russian novel by Tolstoy. If a character expresses admiration for Winston Churchill without additional explanation, that can be assumed to be a reference to a man who was among other things the British Prime Minister during most of World War Two.

Such assumptions are still expected even if the setting has obvious deviations from Real Life, such as the presence of superheroes, vampires, aliens, or a fictional President of the United States. The setting, after all, is Like Reality Unless Noted; the obvious fictional elements are the part that's been noted, and In Spite of a Nail the rest of the world is still assumed to be identical to Real Life.

When it becomes explicit that the setting is Like Reality Unless Noted in some aspect, that's Truth in Television. On the other hand, the audience's subconscious assumption that the setting is Like Reality Unless Noted may be suddenly and obviously disproven for The Reveal that it is actually an Alternate Universe or Alternate History, which may serve as a Tomato Surprise.

Even when stories are not set in the Present Day, they are still assumed to be Like Reality Unless Noted with the necessary adjustments. Historical settings are Like Reality Unless Noted with regard to their particular time period. Similarly, stories set in The Future are assumed to have at some point in the past been Like Reality Unless Noted and moved on from there. Even completely fantastic settings that have their own fictional history, geography, and culture, are probably assumed by the audience to be Like Reality Unless Noted with regard to a number of biological and physical facts. For that matter, even Alternate History stories that are explicitly set in a world not like our own may feature people and events that happened in reality to a far greater extent than mere chance would lead one to expect.

The accusation that a writer Did Not Do the Research is entirely based upon the premise that works of fiction should be Like Reality Unless Noted, and that an incorrect fact is not meant to be correct within the context of the fictional world. For example, it's not uncommon for readers to assume that a superficially Medieval European Fantasy world has the same customs, values, etc. as Medieval Europe. But this fails the logic test for two reasons; one, historical Medieval Europe had no wizards or dragons, and was not on a planet with seven moons and a lavender sky. And two, Medieval Europe covers dozens of cultures evolving (and interacting with dozens of other cultures) over a thousand year period so there was tremendous variation in the prevailing assumptions and values.

(Of course, if the book claims to be factually correct in some or all areas then it pretty much falls under Dan Browning.)

A work that is Like Reality Unless Noted has strong External Consistency. The Celebrity Paradox is an exception to Like Reality Unless Noted. Contrast Call a Smeerp a Rabbit, where people may use the same terms as they do in reality, but to describe entirely different things. See also the Sliding Scale Of Like Reality Unless Noted.

Anime

 * In its first episode, Code Geass claims that Brittania invaded Japan in order to get access to its vast natural resources. Some viewers called foul on this, since in the real world Japan is a fairly resource-poor nation. It takes several episodes before viewers discover that 1) the world of Code Geass is an alternate history set in our equivalent of 1962, rather than a future version of our own Earth, and 2) the resource Brittania wants from Japan is "sakuradite," a fictional mineral that can be used as an isothermic superconductor or energy source rivaling nuclear power, and its discovery in the middle ages caused technology to develop along a very different path.
 * The setting of any given Super Robot is Like Reality Except That One Phlebotinum, from Mazinger Z to GaoGaiGar to Full Metal Panic. The few settings that aren't that tend to be some sort of adventure or journey (Combat Mecha Xabungle, the first half of Tengen Toppa Gurren Lagann). Real Robots, on the other hand, tend to be set.
 * TTGL is hinted to be in the near future. The near evolutionary future. When the map of the world is seen very briefly in one episode, it looks like a future map of the world where the continents have shifted a bit.

Comics

 * Most comic book settings are like this, just with an incredibly extensive "noted" category. Superpowers, magic, alternate pantheons, the confirmed existence of the soul, contact with multiple alien races, and yet everything else is the same as our world.

Film

 * Inglourious Basterds:
 * The town in UHF. It's a normal city with normal people watching their normal Channel 8... but when you see the odd content being aired on Channel 62 and realize all these people and things must have been out there already before they got TV shows, it makes you wonder what anyone found weird or odd about George at the beginning of the movie.
 * It becomes even weirder when you know that almost everything was filmed at recognizable Tulsa, OK landmarks, and the Channel 8 studio was later used in real life by the station that helped the production crew build it.

Literature

 * A more generous interpretation of Dale Brown's work involves this. After all, the setting has clear elements of Alternate History already, such as Wings of Fire predicting the deposing of Gaddafi way before it actually happened.
 * In Anathem, the world presented seems to be a post-apocalyptic Earth. There are lots of mentions of Greek philosophy and mathematics with only the names changed. And there's even a reference to Spock during an early discussion about the different ways Extramuros (normal people) view Avout (people living in the monastery who only come out once every ten years.)
 * Toyed with briefly in Robert Harris' Fatherland, set in an alternate 60s in a Nazi-ruled Europe. There are a couple of mentions of a President Kennedy (who one naturally assumes to be John F Kennedy), but his unlikely characterisation and issues with the timeline are allowed to build up before a minor Reveal that it's actually Joseph Kennedy, his father.
 * In Stephen King's novel, The Long Walk, the setting appears to be America in the 1980s, except for a few blink-and-you'll-miss-it details dropped in the narrative, namely that the "German air-blitz of the American East Coast during the last days of World War II", and the existence of April 31st and a 51st state.
 * A. Sapkowski wrote in his essay Pirog that critics once attacked him for the "anachronism" of placing batiste panties on an ex-princess he mentioned in one of his novels. And added that once that tempest in a teacup subsided, one young author still reacted with cold haughtyness, showing his research on such a subject in his heroine's disrobement scene -- but the effect was "hopelessly spoiled by the description of intercourse that followed, ludicrous beyond any measure and imagination".
 * Inverted in The Restaurant At the End of The Universe, one of the books in increasingly inaccurately named The Hitchhiker's Guide to the Galaxy trilogy. An incident is described in which a reader of the Guide (which more-or-less purports to be a sort of encyclopedia) sued the publishers over one of the more outrageous bits of inaccuracy contained within the guide. The publishers stand by the disclaimer that when reality contradicts what is written in the Guide, then it is reality that is in error. To defend their case, they hired a lawyer who argued that what was written was more beautiful than the "correct" version and truth is beauty.
 * The Thursday Next series plays fast and loose with this. Because it's set in an Alternate History (later becoming an Alternate Present Day), some things happened while others didn't, and vice versa. The problem is that some of the events and books that were "changed" are so obscure, especially to non-Britons, that many readers will have no clue which is which half the time.
 * Some are obvious, of course, such as the presence of the People's Republic of Wales and cheese being a controlled substance with prices in the hundreds. Also the cloned neanderthals and other extinct species.
 * Interestingly though, it seems that as the series progresses, it moves slowly into our reality. For example, Neanderthals can't breed so will soon all be extinct again, and time travel no longer exists. However, there is mentioned in one of the books an "alternate universe" that has been discovered, which sounds just like ours, implying that the whole series is actually set in a different universe anyway and nothing to do with us.
 * Used explicitly in Jack Chalker 's "Wonderland Gambit" trilogy, which is about alternate histories created within some gargantuan virtual reality game. To save computational space, all elements of reality not explicitly changed by the premise are Like Reality Unless Noted--but if magic exists or people are unisex centaurs, an awful lot of Reality may be Noted.
 * Used explicitly in Jack Chalker 's "Wonderland Gambit" trilogy, which is about alternate histories created within some gargantuan virtual reality game. To save computational space, all elements of reality not explicitly changed by the premise are Like Reality Unless Noted--but if magic exists or people are unisex centaurs, an awful lot of Reality may be Noted.

Live-Action TV

 * The remake of Battlestar Galactica runs on this trope despite being set in an extrasolar system partway across the galaxy.
 * The average man's technology and culture remain just like reality in Power Rangers despite humanity having made First Contact and developing hyperadvanced ranger technology. The only noted exception is that the ludicrously rich can afford antigravity craft and such (but never use them in public) and universities now have majors in areas like "Galactic Myths and Legends".
 * In at least one episode of The Twilight Zone, an otherwise normal-looking world turns out to be an almost-perfect duplicate.
 * Ugly Americans is set in a modern version of New York where nonhuman "creatures" (demons, giant apes, etc.) exist as minorities. Spattered throughout the series are hints of how this has created an Alternate History, such as a human-zombie war having taken place in The Sixties.

Meta

 * Can be considered the root cause for a setting having such elements as Anti-Magic or PowerNullifiers which specifically act to counter other setting elements that make it less "like reality" and thereby restore the "mundane" status quo.

Professional Wrestling

 * Not only is Professional Wrestling Like Reality Unless Noted, but, generally speaking, the characters the wrestlers play are like themselves unless noted.

Video Games

 * Ace Combat does a variation. The series is set on an alternate Earth, the proper name for which is Strangereal, where the continents and countries are, to say the least, different. History is similar, but often times, events anywhere from Strangreal's 1995 to 2015 have obvious parallels to real history; Belka is blatantly World War One and then World War Two style Germany, for example. Other nations have clearly visible similarities to the cultures and geography they are based on, e.g. : Characters from Estovakia or Yuktobania are easily mistaken for Russians / Eastern European nationalities. Many fighter planes featured in the series are real planes (licensed from their real-world manufacturers by the game developers, no less) but with twists; the SU-47 Berkut was built as a proof-of-concept machine. On Strangereal, the Berkut went to mass production and became a high-end fighter jet for several militaries before 1995.
 * Doubly-subverted in Custom Robo: At one point, you are asked whether the world is flat or round. If you answer "round," your teammates scold you for joking - revealing that you've actually been on a flat world the whole time - and the promptor asks the question again. When you answer "flat," though, the promptor then reveals that you had been lied to your whole life and that the supposedly flat plane you'd been living on was actually a closed-off portion of a round planet the whole time.
 * The fact that the main character can give the "wrong" answer to this and a similar question is actually Justified, despite how that makes it sound.
 * There's some weirdness here with the Fallout series. The official explanation is that the Fallout world is exactly the same as ours, until sometime in the nineteen-fifties, where the two timelines split. Our world became what we know today, Fallout's world became a world of Zeerust, essentially what America thought 2050 would be like in 1950. Then the bombs dropped. This is just compounded by the fact that the games take place quite a bit After the End. In Fallout 3, you can meet an American History fanboy who honestly believes that the Declaration of Independence was created by the Second Judgemental Congress and sent to King George by airplane.
 * Mega Man Battle Network has an alternate Earth with odd country or region names like "Electopia" for the Japan-equivalent, "Netopia" ("Amerope" in the original Japanese) for an America-Europe equivalent etc. Of course, the main difference is in the series premise, with the different way of browsing the 'net and all.
 * The Metal Gear series can be quite confusing with this. About half of the past events that is referred to in the games actually happened and the other half is made up.
 * It's interesting to note that some of this comes from most of the games' being set Next Sunday AD, and the present day continually catching up to it. Metal Gear Solid released in '98, takes place in 2005. Sons of Liberty released in 2001, takes place in 2007 and 2009. Guns of the Patriots released in 2008, takes place in 2014.
 * At first, The Sims looks very similar to real life.... until you find out that over the various installments of the series and their expansion packs, the games have featured vampires, robots, time travel, magic, alien abduction, werewolves and the Grim Reaper. Why? Rule of Cool, that's why.
 * Star Wars is remembered 500 years in the future, and it seems most things stayed the same without Bungie's existence (or at least Marathon and Halo) in the Halo universe.
 * Although most of the Touhou series occurs on the inside of the Great Hakurei Border, there is a very obvious Outside World that is believed to be a parallel of our own time line alongside the All Myths Are True wonderland, consistent chronologically until at least the moon landing. Of note: the strange college majors of the two popular outsiders are Maribel Han, Relative Psychology, and Renko Usami, Super Unified Physics. Bonus "alternate reality" points if its sister series Seihou is the same Outside World.
 * Then again, there's quite a bit of indication that Renko and Maribel's in the future (commercial moon trip, amongst other things), and Yukari does imply in Curiosities of Lotus Asia that the DS is popular in the outside world.

Web Comics

 * If you write down the latitude and longitude coordinates provided in Homestuck and put them into Google Maps, they are in fact real places. This makes  all the more unsettling...
 * Questionable Content lives in a world where up-to-date indie music references coexist with sentient, anthropomorphic personal computers. The town that it takes place in, Northampton, also appears accurate to modern day save for a few eccentricities.