in Editing
Exposition in speculative fiction without the info-dump
Readers of fantasy and science fiction will work to understand a new world, provided you do not make them sit through a lecture first.
Speculative fiction has a particular problem. Its readers are entering a world with its own history, rules, technologies or magic, and they need some of that to follow the story. Yet the more a writer explains, the more the story stops. The info-dump, a block of explanation that halts the narrative, is a familiar problem in the genre.
Trust the reader
Readers of fantasy and science fiction are used to not understanding everything at once. Many of them enjoy piecing a world together from context. An unfamiliar word used confidently, in a sentence where its meaning can be partly inferred, is often more engaging than the same word followed by a definition.
Say a character "checked the charge on her sidearm before stepping through the gate". We do not know what the gate is, but we know it matters and that it may be dangerous. That uncertainty pulls us forward. A paragraph explaining the history of gate technology would satisfy a curiosity the reader has not yet developed.
Give information when it is needed
The most reliable principle is to explain things at the moment the reader needs them, and not before. If the magic system has a cost, readers do not need to know about it until a character pays it. If the political structure matters, it can emerge when a character runs up against it.
Information delivered at the point of need has context and stakes. The same information delivered in advance is just a list to remember.
Avoid the "as you know" conversation
A common workaround for exposition is to put it into dialogue. This can work, but only if the characters have a reason to say it. Two characters telling each other things they both already know, for the reader's benefit, is transparent. "As you know, the Council has ruled for three hundred years" is a line readers rarely believe.
Dialogue exposition works better when one character genuinely does not know, when there is disagreement about the facts, or when the information is revealed under pressure. A newcomer, an argument or a confession all give characters a reason to explain.
Let the viewpoint character filter
Characters take their own world for granted. Someone who has lived with a technology all their life does not think about how it works; they notice when it fails. Writing exposition through a character's ordinary experience, rather than stepping outside to explain, keeps the reader in the story and makes the world feel lived in.
This also means some things never need explaining at all. The reader can accept that the trains run on something other than coal without learning what.
Look for any passage of more than a paragraph or two that describes history, systems or rules without anything happening. Ask whether the reader needs it now, whether it could be broken into smaller pieces spread across later scenes, and whether some of it could go entirely.
The world-building notes behind a speculative novel are often extensive, and should be. Most of them belong in the writer's files rather than on the page. What reaches the page is the part the story uses.