A short, curated guide — not an automatic related dump. Figures come from SubMouse's safe-for-work directory when we have them.
r/worldbuilding (about 1.9M members, directory rank #571) is for creating new worlds and settings. Reading fantasy, reading science fiction and general writing craft each have clearer homes when you are not inventing a setting.
Stay on worldbuilding for maps, cultures and setting design. Use Fantasy for fantasy reading discussion, scifi for science-fiction media, and writing for prose craft beyond world design.
r/worldbuilding — Worldbuilding - Explore Every Impossibility
For artists, writers, gamemasters, musicians, programmers, philosophers and scientists alike! The creation of new worlds and new universes has long been a key element of speculative fiction, from the fantasy works of Tolkien and Le Guin, to the science-fiction universes of Delan…
Reddit Fantasy
When to choose it: Discussing fantasy books and media rather than building a setting.
Why it is here: Public description: r/Fantasy is the internet's largest discussion forum for the greater Speculative Fiction genre. Fans of fantasy, science fiction, horror, alt history, and more can all find a home (about 4M members, rank #240). Listed as related.
How it differs from r/worldbuilding: Fandom/reading focus versus world creation.
scifi
When to choose it: Science-fiction discussion rather than inventing a universe.
Why it is here: Public description: Science Fiction, or Speculative Fiction if you prefer. Fantasy too. Asimov, Bradbury, Clarke, Dick, Heinlein and other SF books. SF movies and TV shows. Fantasy stuff like Tolkien (about 4.5M members, rank #205). Listed as related.
How it differs from r/worldbuilding: SF consumption versus worldbuilding craft.
Writing
When to choose it: Writing craft, critique and process beyond setting design.
Why it is here: Writing community (about 3.4M members, rank #300). Neighbouring creative room for prose rather than maps.
How it differs from r/worldbuilding: Prose craft versus world/setting design.
Run the automatic finder for r/worldbuilding (results are matched from our directory; that page is not indexed): Find related to r/worldbuilding.
Members and public descriptions come from SubMouse's safe-for-work directory (as of 2026-11-02 UTC); 7-day growth measured from 2026-10-26. Posts/day and culture claims appear only when we have them — missing fields stay n/a. Directory rank is listing order. Communities outside the published Top 100 open in the info tool instead of a full community page. Guide updated 2026-11-07.