World-building depth vs. exposition
The paradox of second world fantasy is that the more fully you have built your world, the less of that building you should show on the page. Readers come for a story, not a geography lesson. The world-building work belongs in the writer's notes, not in the opening chapters. What appears on the page is the world as characters experience it — through sensory detail, through the assumptions embedded in dialogue, through the things characters find unremarkable that readers find fascinating. Exposition is a last resort. Readers can absorb an enormous amount of unfamiliar information if it arrives through drama rather than description.