Science fiction has been, and still is, a hugely popular genre that screenwriters constantly go back to. It works especially well in cross-genre stories. Stranger Things, for example, is a cross-genre science fiction and coming of age story. Alien is a science fiction and horror story. THX1138 is a science fiction and a prison break story (where the whole of society is the prison). George Orwell’s 1984 is a science fiction story (about a dystopian future) and a political thriller.
Science fiction transposes today’s fears and dreams into a new version of reality, one that’s usually set in the future, or the near-future. It’s a place with different technologiesm its own rules and cultures. Historical fiction does much the same thing by speculating on what life must have been like in the past.
The characters may enter an enlightened world with life enhancing technologies, or live in a repressive dystopian system that must be escaped from if the protagonist is to retain his or her humanity.
The space setting often reuses traditional story tropes in new ways: the classical quest, the band of heroes, and the journey through the wilderness (recalling the wagon trek across the old west), the prison break, the revenge story, the sherif in pursuit of outlaws, etc.
The genre often features a vehicle of some kind: a rocket, a spacecraft, a submarine, or a time machine. The spacecraft is a kind of high tech sailing boat with a captain and a crew. They come in different shapes and sizes: old rusty freighters carrying ore from mining planets, dazzling military battleships, and flashy muscle cars driven by rebellious young heroes.
It’s not just about technology — science fiction is also about people coping with new challenges, changes in technology, and the discovery of aliens and new cultures. Science fiction is a sociological fiction as much as technological one. Star Trek is not about warp drives, it’s about people, the crew arguing or getting along with one another, encountering new worlds and different peoples. Babylon 5 is not about a huge spaceport, it’s about migration, politics, human displacement, international relations, and people learning to make a new home.
Science fiction stories work well as what if...? scenarios. The Handmaid’s Tale is: what if we lived in a brutally repressive theocracy that viewed women as baby-making machines? Science fiction lends itself well to this kind of simplification: what if robots become our masters? What if we can travel in time? What if there’s no male or female? What if people lived forever? What if everyone in a society was executed at the age of 21? What if a deadly virus wiped out most of the population?
Science fiction frequently merges with fantasy fiction. Fantasy fiction is another story type that works well as part of a cross-genre package. Science fiction is usually thought of as being about aliens, robots, spacecraft and future cities (the rational), while fantasy is about unicorns, and castles in misty fairytale landscapes (the magical). The Jedi in Star Wars possess the kind of magical powers one might expect from a wizard in a fantasy adventure. And, conversely, there are elements in fantasy stories that are given rational explanations more akin to science fiction. The superhero story is a fusion of science fiction and fantasy.
The science fiction genre scales well. It works as a story about a wandering lone hero travelling through a wilderness (Mad Max, Book of Eli), stories about the village (The Village, Village of the Damned), the town (The Truman Show), the city (Cloverfield), the megalopolis (Judge Dredd), the planet, (War of the Worlds, Planet of the Apes), the galaxy (Star Wars, Flash Gordon).