Nobody has actually visited a planet populated by alien civilizations, walked through a city protected by superheroes, or watched giant robots battle for the future of Earth.
Yet a great movie or television show can make audiences forget that for a while. That is the strange magic of fictional worlds. Viewers can know perfectly well that what they are watching is impossible and still become completely invested in it. They worry about characters, remember fictional locations, debate imaginary technology, and sometimes know the history of a made-up civilization better than the history of their own hometown.
So what makes that happen? Alexander Kurtzman explains that it usually is not one enormous detail. Instead, believable fictional worlds are built from hundreds of little things: rules, geography, history, technology, relationships, traditions, language, politics, clothing, architecture, and countless background details. When all those pieces fit together, even the wildest world can start feeling surprisingly real.
Every World Needs Rules
The first rule of creating an imaginary world might be surprisingly simple: it needs rules.
Those rules do not have to resemble reality. Spaceships can travel incredible distances. Robots can transform into vehicles. Aliens can possess technology centuries beyond anything humans currently understand. Superheroes can climb walls or fly through the sky. Audiences are usually willing to accept almost anything. What becomes harder to accept is when the rules suddenly change whenever the story needs them to.
If a fictional technology can solve every problem instantly, why did the characters struggle with a similar problem earlier? If a villain has an incredibly powerful ability, why do they suddenly stop using it during the final confrontation? That is where consistency becomes important. Once a story establishes what is possible, viewers begin unconsciously keeping track. In a strange way, the more fantastic a fictional universe becomes, the more important its internal logic can be. Audiences do not need a scientific explanation for everything. They simply need to believe that the characters live in a world with boundaries.
A Little History Goes a Long Way
Real places existed before we arrived, and believable fictional places should feel the same way. History gives a fictional universe depth. Maybe two groups distrust each other because of something that happened generations earlier. An old war could explain why certain characters behave the way they do. A monument might commemorate an event that happened long before the current story. Not all of that history needs to be explained.
In fact, sometimes it is better when it isn’t. Imagine two characters casually mentioning an event that the audience has never heard about. Neither character stops to explain it because, to them, everyone knows what happened. That tiny moment suggests there are stories beyond the one currently being shown. It creates the feeling that this world existed before the opening scene and will continue existing after the credits.
Geography Matters More Than It Seems
Where exactly is everything? It sounds like a boring question until a fictional world gets geography wrong. Audiences develop mental maps surprisingly quickly. They remember that one neighborhood is dangerous, another planet is far away, or a particular building sits near an important location. Geography affects stories because distance matters.
How long does it take characters to get somewhere? What separates one region from another? Does a city have wealthy neighborhoods, industrial areas, transportation systems, parks, restaurants, and places where ordinary people live?
Even futuristic or fantastical places benefit from these everyday details. A fictional city becomes more believable when it feels like somewhere people actually have to navigate rather than a collection of cool-looking sets. The audience may never see a map. They still want to feel like one exists.
Technology Should Feel Like Part of Everyday Life
Science fiction offers some of the most obvious examples of world-building because technology can immediately tell audiences what kind of society they are visiting. The interesting part is not simply inventing a futuristic gadget. It is figuring out what happens after everyone starts using it. Consider something as ordinary as the smartphone. It changed communication, photography, shopping, navigation, entertainment, dating, work, transportation, and countless other parts of everyday life. Fictional technology should create similar ripples.
If people can instantly travel enormous distances, what does that do to transportation? If intelligent machines are everywhere, what jobs do people perform? If medical technology can cure previously deadly conditions, how does that change society? The best fictional technology often feels ordinary to the characters using it. They do not stop and stare at something simply because the audience thinks it is amazing. To them, it might be the equivalent of turning on a microwave. That casual familiarity helps sell the illusion.
Culture Exists in the Small Details
Culture is another area where tiny details can make an enormous difference. What do people eat? What do they wear? How do they celebrate? What sports do they watch? What music do they listen to? What do children learn? What counts as rude? What do people joke about? A fictional culture does not necessarily need lengthy explanations for these things. Sometimes a strange food sitting on a table or an unfamiliar greeting between two characters can accomplish more than a long speech.
Background details are especially powerful because they suggest that the world continues beyond the main characters. People are working, eating, traveling, arguing, celebrating, and living their lives even when the hero is not around. Suddenly, the fictional universe starts feeling populated rather than constructed.
Relationships Make Big Worlds Feel Personal
A universe can contain thousands of planets and still feel strangely empty if audiences do not care about anyone living there. That is why relationships are such an important part of world-building. Families, friendships, rivalries, romances, mentorships, and alliances give viewers something familiar inside unfamiliar surroundings.
Kurtzman’s career offers plenty of examples of projects involving enormous fictional concepts and recognizable worlds. From Transformers to The Man Who Fell to Earth, his work has frequently crossed into stories involving science fiction, unusual technology, extraordinary characters, and worlds operating beyond ordinary reality.
But giant concepts alone are rarely enough. A battle involving the fate of the world becomes much more interesting when audiences care about the people caught in the middle of it. Relationships provide scale. The universe might be enormous, but viewers experience it through individuals.
Language Can Tell Us Who Belongs Where
People in the real world speak differently depending on where they grew up, what they do for a living, how old they are, and which communities they belong to. Fictional worlds can use language the same way. That does not necessarily mean inventing an entire language. Slang can do it. So can nicknames, professional terminology, military phrases, jokes, insults, titles, and expressions.
Characters who share a profession might use shorthand outsiders do not understand. People from different places might have different names for the same object. Those differences subtly tell audiences that groups within this world have their own identities. The trick is making the dialogue feel natural. Characters should not constantly explain things everyone around them already knows just because the audience needs information. Sometimes letting viewers figure things out is part of the fun.
The Background Can Tell Its Own Story
Some of the best world-building happens behind the actors. Look at the walls. What advertisements are there? What businesses exist? What does public transportation look like? Are there political posters? Graffiti? Old buildings next to new ones? Costumes can reveal social status. Architecture can suggest history. Vehicles can reveal technology. A crowded marketplace can show how different groups interact.
None of these details necessarily needs to become part of the plot. That is exactly why they work. They exist because they belong there, not because the hero needs them. It is one reason fans often discover new details when rewatching favorite movies and shows. Once viewers stop concentrating entirely on the main story, they can start exploring everything happening around it.
Imperfection Can Make a World More Believable
Real societies are messy. Technology breaks. Governments disagree. Buildings get old. People complain about their jobs. Rules have exceptions. Traditions sometimes make little sense because they developed hundreds of years ago. Fictional worlds can benefit from the same imperfections. A futuristic city where every building is spotless and every piece of technology works perfectly might look impressive, but it can also feel artificial.
Add an old machine someone has to kick twice before it starts working, and suddenly things feel a little more lived-in. Characters complaining about ordinary problems can accomplish the same thing. Not everyone needs to be discussing the fate of civilization all the time. Someone still has to make dinner. Those ordinary moments can make extraordinary worlds much easier to believe.
Consistency Is the Secret Ingredient
Ultimately, believable world-building comes down to consistency. A fictional universe does not have to follow the rules of reality. It has to follow its own rules. Its history should influence the present. Its technology should affect daily life. Its geography should influence travel. Its cultures should shape its characters. Its relationships should have histories of their own.
When all those pieces reinforce one another, audiences stop thinking about the fact that somebody invented everything they are seeing. They simply enter the world. That may be one reason elaborate fictional universes can inspire such devoted fan communities. Fans do not just follow individual plots. They learn the places, histories, characters, technology, traditions, and rules until the fictional world starts feeling strangely familiar.
The Best Worlds Feel Bigger Than the Story
Perhaps the greatest sign of successful world-building is the feeling that there is more to discover. The movie ends, but audiences can imagine what is happening somewhere else. There are cities they have not visited. Characters they have not met. Historical events they have only heard mentioned. Technologies whose full possibilities have not been explored. The story shown on screen starts feeling like one small window into something much larger.
That is what makes fictional worlds so much fun. Audiences know the spaceships are not really flying. They know the alien planets do not exist. They know those futuristic cities were created by writers, designers, artists, actors, visual-effects teams, directors, producers, and countless other people. But for a couple of hours, none of that matters. Give an imaginary world enough history, rules, personality, relationships, and tiny everyday details, and audiences will happily believe in it. At least until the credits roll.