Often in media, the creator wants to tell a story about people who aren't like the majority of the target audience, but worries that said audience won't be able to relate to those different people. So they will put in a protagonist or point of view character who is like the presumed audience, and therefore "relatable". The hope is that the audience will then transfer their ability to care for the protagonist to the group of people the story is actually about.
In a mainstream Hollywood film, for example, the protagonist is likely to be a white male, middle-class, heterosexual/heteroromantic, cisgender, able-bodied, high-school and college educated person, while the majority of the characters are anything but those categories. A film aimed primarily at black people will substitute "black", etc for "white", a Japanese film would have a Japanese person as the point of view character, and so forth. Sometimes this can be stretched a bit; a mainstream Hollywood film might have a middle-class able-bodied black man as the protagonist in a story about wheelchair-using urban youth, for example.
While this storytelling device is often used in situations involving discrimination, it is not confined to those by any means.
Usually, the audience-like character has their own subplot within the story, overcoming their prejudice or romancing a member of the unlike-audience group. If handled poorly, this can become a Plot Tumor that takes time away from the film's supposed focus story.
However, handled well and in moderation it can be a good thing. It's true that many people relate better to a protagonist/point of view character they can identify with on some level. But it can also come across as insulting both to the target audience (if the story assumes the audience knows absolutely nothing about the outside group) or to members of the outside group (suggesting that that group would not be able to handle their own problems without the intervention of an in-group person, especially irritating if the POV character is either completely made up or a "normalized version" of an outside group member.)
Common subtropes of this are Homegrown Hero (where a 'representative' for the makers' (or audience's) culture or country fills some screentime for no other reason than familiarity), Foreign Correspondent (where a person from "our country" goes to "their country" and gets involved in local affairs and issues), White Man's Burden (where the protagonist (usually white) works to uplift disadvantaged people of the outside group) and Black Like Me (where a member of the audience's group goes undercover as a member of a different group to discover what life is like for the other group). Examples that are purely one of these subtropes should go on those pages.
Compare Vanilla Protagonist (which is about the more general use of ancillary characters who are more interesting than the lead), First-Person Peripheral Narrator (which is built on some of the same logic as this trope and also involves focusing on a character who isn't actually the protagonist), Audience Surrogate (where one character is designated to ask the sort of questions the audience would logically be asking during the story), Escapist Character (where the protagonist differs from the audience, but in positive, wish-fulfilling ways that the presumed audience finds relatable) and This Loser Is You (when the executives believe that a character with major flaws will be easier for the audience to identify with, because the audience members themselves are similarly flawed). Also compare with The Watson (whose job in the narrative is to ask the questions that the audience is likely to have so that another character can explain them) and contrast The Everyman (where the main character is so bland they have no character). See also But Not Too Foreign, But Not Too Black, and But Not Too Gay (or But Not Too Bi), where a character is part of a demographic that's not the same as the majority of the audience, but is still pretty close to being in their demographic.
Contrast Mighty Whitey, in which a person from the presumed audience's culture goes somewhere and is better at what the natives are good at than the natives themselves, and Exotic Backdrop Setting which is what happens when someone from the audience's culture goes somewhere, and the exotic people/culture there only serves as a backdrop to the protagonist's actions, with local affairs and issues largely irrelevant to the plot.
- Yuu Haruna of Fuuka is a black-haired, middle-class, high school Japanese boy with an average build and an unremarkable reputation, surrounded by more exuberant and distinguished individuals. He also appeals to modern audiences by being more interested in social networks than in the real world and has no idea where to take his life after he finishes high school.
- Real: While the later manga volumes widen the focus to be more about the team members themselves, the initial viewpoint character is an able-bodied high school dropout who becomes involved with the world of wheelchair basketball after a chance encounter. Also has a parallel storyline about a "normal" athlete becoming handicapped and having to learn about being in a wheelchair.
- While he isn't the main character, Yami Sukehiro of BlackClover is a Japanese-styled man living in a western-styled country. This gives the (originally Japanese) audience a relatable character. In addition, his mentor relationship with Asta and the way he teaches him Ki heavily influences Asta. Actually, much of the training Asta was doing on his own resemble Japanese techniques.
- Superdreadnought Girl 4946 is about a Cute Giant named Mana (4946 is her height in centimeters) who fights monsters of a similar size. Because it's a shonen manga, though, Mana's page time is split with her love interest, the Tiny Schoolboy Tobita.
- Sonic X: Presumably, this is the reason why the human kid Chris Thorndyke was added to the main cast. Unfortunately, most real-life kids don't live in big fancy houses, nor do they have personal butlers or maids, so it didn't really work.
- The Last Samurai: A white American army officer is sent to Japan to modernize their military and comes to admire samurai culture. (In Real Life, the equivalent person was French, but the movie was made for Americans.)
- Writer Marissa Lee noted that this practice is extremely common for Hollywood works set in Asian locales. The white lead actor is usually justified by having the character be adopted (White Devil), an exchange student or visiting foreigner (Lost in Translation, The Fast and the Furious: Tokyo Drift), or just Fake Mixed Race (Kyo in The King of Fighters movie, Kai in 47 Ronin).
- The Help: A white woman interviews black women working as maids in the Deep South in The '60s and becomes involved with their personal lives and struggles.
- Blind Side: The story of a young black man who overcame poverty to become a successful professional football player—told from the perspective of the white family that helped him.
- Rain Man is purportedly about autistic Raymond, but is told from the POV of his non-autistic brother.
- Red Tails notably averts this trope; George Lucas had trouble getting funding for years because he had the radical notion that a film about the heroic Tuskegee Airmen should be about the Tuskegee Airmen being heroic, rather than the noble but conflicted white officer who teaches them how to be heroic.
- Dances with Wolves tells of the plight of Native Americans through a white male lead.
- The Ramen Girl: An American woman is stranded in Tokyo after breaking up with her boyfriend. She ends up in a ramen shop.
- Many documentaries use this device: the interviewer or narrator is from the audience's culture, introducing and examining the lives of more "exotic" people.
- This is exactly the reason why Raymond Burr's scenes as a Foreign Correspondent were added to Godzilla: King of the Monsters!.
- 2013 movie The Impossible has an English family struggling to survive after the 2004 Indian Ocean tsunami. The real people the story is based on were Spanish, but British people were thought to be more relatable to the target audience.
- Django Unchained is supposedly about Django and the struggles slaves in the American South had, but as Will Smith commented, "Django wasn't the lead, so it was like, I need to be the lead. The other character was the lead!" (The other character being the white guy.)
- Part of the problem there is Smith was going by the original script, which had a more generic ending and a truncated third act. After that ending was shot, Tarantino et al. realized it wasn't enough in light of everything that had gone before, so a new ending was conceived and the third act greatly extended, this time focusing almost entirely on Django.
- 12 Years a Slave is the story of slavery told, not from the perspective of those born into it, or of those kidnapped from Africa and forcibly shipped to the Americas, but of a free, educated black man from the north.
- The Forest (2016) is a horror movie about the famous Aokigahara Forest in Japan, but the principle characters are white Americans.
- Even though many of the real people involved in the Stonewall riots were black or Latino and a number of them were transgender women, Stonewall focuses on a fictional cisgender white teen from Indiana. The specific justification given was that a White Male Lead from the American heartland would be more relatable to the audience. Unfortunately, audience reaction (and thus box office reaction) to this justification was... shall we say... poor.
- Averted with Crazy Rich Asians, but not without some arguing. Early on, there was a push to get a white actress to play Rachel (the film's lead), as some of the prospective producers were worried that having an entirely-Asian cast would alienate white audiences.
- The Forbidden Kingdom is unabashedly about Jet Li and Jackie Chan running around in mythological ancient China, but the actual protagonist is some ordinary white kid who was barely even mentioned in the marketing materials.
- A Walk with Ian, a children's book about a non-autistic girl named Julia taking a walk with her autistic brother Ian.
- The book One Flew Over the Cuckoo's Nest is an inversion. The story is about how a "normal" person changes the lives of a group of mentally disturbed people, but the point of view character and Unreliable Narrator is one of the group being affected. The Film of the Book uses this storytelling device straight.
- Archie Goodwin, The Watson and narrator of the Nero Wolfe mystery stories. Compared to Wolfe, who is a veritable smorgasbord of eccentricities, quirks and intellectual pursuits in a manner fitting for a Great Detective, Archie is basically an average working stiff who happens to work as the Great Detective's personal assistant, and tends to puncture his grandiosity with sarcastic comments.
- The Tyra Banks Show: Tyra would often disguise herself and go undercover for a day to see what life was like for non-supermodels. She put on a Fat Suit, she dressed as a man, she went homeless, and was a stripper.
- Orange Is the New Black has a very diverse cast that reflects the realities of its prison setting, but the protagonist is as stereotypical a middle-class white girl as you could come by minus her bisexuality, and her crime was a more 'understandable' minor offense committed 10 years before her arrest. The creators have confirmed that the show couldn't have been made unless they had a protagonist like her. Although in this case it's just a happy coincidence that the real-life person she's based on happens to be this way too.
- Leverage: Nate Ford is an honest man who runs a crew of thieves. He talks about living a normal life and having a normal job throughout the show.
- OnceUponATime: Emma Swan grew up in our world and is introduced to the fairy tale world alongside the viewers.
- Eureka: Marshal Jack Carter and his daughter are average people living in a town of super geniuses.
- Dispatches From Elsewhere: The four protagonists are very different people, but the show makes very clear that anyone can empathize with them to some small extent. The narrator outright exhorts the audience to put themselves in the characters' shoes.
- The Office (US): Jim is a laid-back, sensible young man in a firm populated by lunatics, fascists, and buffoons.
- It would be a safe bet to suggest that every fighting game in existence has an American fighter in it, mostly to ensure that a huge portion of the game market have one character that represents them. The Soul Series posits a unique challenge because it is set in the 16th Century and the USA doesn't exist yet. The solution? Rock Adams, an Englishman stranded in the new world as a boy and raised by Native Americans, so he fits nicely into the role of the "American" character.
- Age of Empires III has the Black family:
- Morgan, an English Hospitaller Knight, in a secret mission to the New World at a time when there weren't English colonies there (the Hospitallers are only playable in campaign mode).
- John, a Colonial American frontiersman during the French and Indian War.
- Nathaniel, John's half-Iroquois son fighting in The American Revolution (his campaign is the Iroquois civ's one).
- Amelia, Nathaniel's daughter, an early American railroad developer in the US and South America.
- Chayton, Amelia's half-Lakota son during the Great Sioux War (Sioux civ campaign).
- Katawa Shoujo: Hisao, a "normal" boy, develops an "invisible" physical handicap and must attend a school for the physically disabled, learning about their issues and struggles. Downplayed in that his arrhythmianote does factor into the plot and sometimes limits what he - and by extension the player - can do.
- Examined in this Cracked.com article, specifically the item titled, "Sci-Fi Needs a Straight Man Like a Laurel and Hardy Routine".
- This is why most Transformers shows have the giant alien robots hanging out with human kids.
- Futurama: Set in a delivery company in 3000 AD New York owned by a senile 160 year-old scientist that employs a one-eyed female alien, a jerkass robot, a Jamaican manager, a Chinese-Martian Valley Girl-like student, a Space Jew alien lobster-thing and the protagonist, an unfrozen 20th century White Male School Dropout.