Science fiction is the genre of consequences. You change one thing about how the world works, then follow it honestly, including to the places you did not want it to go.
Most weak science fiction fails at the second step. The idea is interesting and the world around it is unchanged.
One change, followed all the way
Pick your single premise: a technology, a discovery, a social arrangement, a physical law that differs.
Then ask what it breaks.
If people can upload memories, what happens to courts, to grief, to inheritance, to the concept of a witness? If a colony ship takes ninety years, what religion does it invent? If a machine can tell whether you are lying, who controls it, and what happens the first time it is wrong?
The second and third order effects are where the story is. The technology is the setup; the society that formed around it is the book.
A useful test: could this plot happen without the science fiction element? If yes, you have a mainstream novel in costume. That can still be good, but it will not satisfy readers of the genre.
How hard does your science need to be?
"Hard" and "soft" are a spectrum, not a judgement.
- Hard SF keeps the physics real and treats the constraints as plot. No faster than light, so travel takes decades and relativity is a story problem. Readers of hard SF will check your maths, and the pleasure is partly that it holds.
- Soft SF uses the science as a frame and puts the weight on people, politics or society. Faster than light exists because the story is about an empire, not about propulsion.
Both are legitimate. What is not legitimate is inconsistency. Pick your rules and never break them for convenience. A ship that takes three weeks in chapter two and three days in chapter nineteen because the plot needs it costs you the reader's trust in everything else.
The practical version: you do not need to explain how it works. You need to know what it costs, what it cannot do, and to be consistent about both.
The exposition problem
Science fiction has more to explain than any other genre except epic fantasy, and explaining is what kills it.
What works:
Deliver at the point of use. Explain the atmosphere processor in the scene where it fails, not on the page where the character walks past it.
Use the specific noun and move on. "She clipped the rebreather and went outside" tells you the air is wrong, the problem is routine, and the technology is mundane. Three facts, no paragraph.
Let people be casual about their own world. Nobody explains plumbing to their colleagues. Characters who are blasé about the extraordinary are the fastest way to make it feel real.
Put the explanation in a conflict. Two characters arguing about whether the reactor can hold is exposition the reader will actually absorb, because something is at stake in the answer.
What does not work: the briefing scene, the newcomer who asks convenient questions, the prologue that explains the war, and the paragraph beginning "In 2187, humanity...".
Make the future strange in small ways
Big changes are easy to imagine and easy to write. The texture comes from small ones: what people eat, what is rude, what jobs no longer exist, what children are taught, what nobody thinks about any more.
A character irritated by a trivial inconvenience that could only exist in your world does more than a page of description. This is the same principle as worldbuilding in fantasy, with different furniture.
Be careful with names and jargon. Readers will carry a lot, but front-loading twelve invented nouns in chapter one is the most common reason people bounce off a science fiction opening. Introduce them at the rate the story needs them, as how to start a novel covers.
The subgenres
- Space opera. Big scope, politics, war, found family on a ship. Carried by character; the science can be soft.
- Hard SF. Constraints are the plot. Smaller in scale, precise, often set close to home.
- Dystopian. A society built on one terrible premise. Needs the premise to be plausible and the resistance to be costly, not inevitable.
- Cyberpunk. Corporate power, body modification, information as the battleground. Voice and texture do most of the work.
- First contact. The central question is comprehension. Resist making the aliens into people in costume.
- Military SF. Procedure, hierarchy and competence. Readers in the field will check it.
- Climate and near future. Currently the most commercially active corner, and the most dependent on getting the details right.
Doing this in BookZeta
Front-load the rules. Write your premise and its limits into the story description before you generate anything, including what the technology cannot do. A synopsis naming the one change, its cost and its consequence produces a consistent book. One that names "sci-fi, space, adventure" produces a generic one. Writing a story description that gets good results covers the rest.
Then put the world itself in the Series Bible as entities: ships, corporations, technologies, factions, treaties. Each one takes a category and relationships to other assets, which is how you keep a political map straight across a long book without holding it in your head. Settings cover the places. Continuity and plot holes covers the pass that catches rules quietly expanding, which is the specific failure mode of science fiction drafts.
The science fiction page covers what BookZeta generates for the genre, and if the book is the first of several, how to write a book series covers keeping a future consistent across volumes.
