If you want to write science fiction or fantasy, I recommend giving Orson Scott Card's How to Write Science Fiction & Fantasy a read, maybe multiple reads. This is a short guide, less than 140 pages of text, but it's packed with cogent advice. While most books on writing dwell on general skills, such as the mechanics of building sentences and creating effective dialogue, Card focuses on problems and skills at the story level targeted at issues particular to the science fiction and fantasy genres. For example, he devotes one of the book's five chapters to world building.
In the first chapter, he attempts to describe speculative fiction by defining its boundaries. He explains that science fiction and fantasy are labels defined by the publishing industry, sometimes useful in helping readers find your work and sometimes a way to pigeon-hole you. The terms also label a "fluid, evolving community of readers and writers" (p. 17) as well as a "ghetto in which you can do almost anything you like" (p. 17). His clearest definition states: "science fiction and fantasy stories are those that take place in worlds that have never existed or are not yet known" (p. 18). This covers a lot of works that would not ordinarily be considered speculative. However, if a story does not fit this definition in some way, it's not in the speculative genre. What about the boundary between science fiction and fantasy? Card provides a somewhat accurate rule:
If the story is set in a universe that follows the same rules as ours, it's science fiction. If it's set in a universe that doesn't follow our rules, it's fantasy (p. 22).In either case, the writer must define the limits of technology or magic early in a story and stick to them.
The longest chapter covers world creation. Card discusses where ideas come from, using some of his own works--Ender's Game and Hart's Hope--as examples. Hart's Hope began with the map of a walled city that Card drew to pass some time. He then asked himself questions about the city, named the various gates and determined their particular functions. Asking questions and then more questions, Card contends, is the key to world and story creation. Once you have the germ of an idea, Card emphasizes the importance of creating rules of time, technology, and magic for an invented world. Characters will have to contend with those rules just as we have to wrestle with the physical laws limiting our abilities. Card warns that readers will notice if a writer is sloppy with rules or breaks them. Those readers will feel betrayed. Card also comments on creating geographies and cultures.
The fourth chapter covers writing, namely exposition and diction. Card discusses how to guide readers into the strangeness of an invented world, using Octavia Butler's Wild Seed as an example. Later in the chapter, he discusses how to use appropriate diction for an invented world.
In the final chapter "The Life and Business of Writing," Card discusses markets, agents, and query letters. He comments on the usefulness of classes, workshops, conventions, and professional organizations. Keep in mind that How to Write Science Fiction and Fantasy was published in 1990. Much of the information in this chapter is dated as the internet has opened many new markets for speculative fiction writers. But some of Card's advice is timeless. Consider his amusing but apt comments on the writer's self-image. Card argues that a writer must believe two things at all times.
1. The story I am now working on is the greatest work of genius ever written in English.Perhaps holding contradictory opinions simultaneously is a sign of madness, but the writer has to call on both of these ideas to do his work, calling on number one when submitting the story to an editor and number two when revising it. Two points come up over and over again in How to Write Science Fiction and Fantasy, and if you get nothing else out of the book, you should at least remember to honor the rules you create for your world and honor your reader's expectations.
2. The story I am now working on is worthless drivel (p. 109).