Worldbuilding is the creation of a fictional world, with its places, history, cultures and rules, that feels believable and consistent within the story.
Where the term comes from
Merriam-Webster defines world-building as the creation of a fictional world, especially in science fiction and fantasy, that is believable and consistent within the context of the story. The Wikipedia article on worldbuilding describes it as constructing an imaginary world or setting, with qualities such as history, geography, culture and ecology, and says that before 1900 most of it was done by novelists, who could leave part of the imagining to the reader. Brandon Sanderson, in his third law of magic, offers a caution for working writers: expand what you already have before you add something new. He also describes worldbuilder's disease, the habit of practising worldbuilding at length while neglecting prose, characterisation and plot, and warns that exposition can bury a story.
An example
In Harrowmere, rain falls only in the two weeks after midsummer. A writer who decides this has to follow the consequences. Everyone stores water in sealed cisterns, so the richest family is the one that owns the deepest cellar. Children are named for the rain they were born in. A wedding in the dry season is a statement that the couple expect to be provided for. Not one of these details needs a lecture. They surface when a character refuses a guest a second cup of water, or when a farmer notices who was not invited to the rainy-season feast.
Common mistakes
- Explaining the world in long blocks before the reader has a reason to care.
- Inventing details that never touch a choice. If a custom never changes what anyone does, readers will treat it as scenery.
- Letting the rules drift. A world that is consistent in chapter two and loose in chapter twenty teaches readers not to trust it.
- Adding new features when a deeper use of the existing ones would do, which is Sanderson's warning in action.
- Spending years on maps and histories while the story waits.
How to check your manuscript
Choose ten invented elements: places, customs, objects, laws. For each, find a scene where it changes what a character does or says. Mark the ones that never do. Then list the rules of your world as short sentences and search the manuscript for places that break them. Finally, read an opening chapter and mark every sentence of explanation, and ask whether the reader needs it now or could learn it later from a character's behaviour. The guide to worldbuilding goes through the main layers, and the worldbuilding template offers a place to keep them. A story bible is the usual home for the finished answers.
In Musael, world and characters keeps places, objects and events in one codex that links back to the manuscript, and continuity checks test the rules you set against the text.