r/SciFiConcepts↗
Science Fiction Concepts, Ideas, Plots, and Worldbuilding
scifi ideas and concepts. These science fiction concepts can be based in hard sci-fi or can come from science fantasy. The only thing that matters is that the concepts could be reasonably found in a SF book, film or short story. If you have too many ideas to write about or are just looking for discussion then this is the right sub for you. Post your scifi concepts, ideas, plots and worldbuilding
31k subscribers115 posts / mo in Sep 2026 (incl. ~1% by known bots)96 authors / mosince 2010
r/SciFiConcepts has 31k members (+27% over the last 12 months). It gets about 115 posts a month from 96 people. Top topics: Alien Invasions, Space Travel Adventures and Alien Encounters and Human Futures.
When to post on r/SciFiConcepts
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How r/SciFiConcepts has grown
Subscriber growth
Subscribers over time
Monthly activity
Posts, comments and authors per month
Topics and brands on r/SciFiConcepts
Top topics
Share of the subreddit's posts
- Alien Invasions1.3%
- Space Travel Adventures1.1%
- Alien Encounters and Human Futures1.1%
- Humanity in Space1.0%
- Alien Encounters0.9%
Brands people mention
Most-mentioned brands and sites, last 12 months
- Atomic Rockets
- Orion's Arm
- Substack
- Medium
- IMDb
Everything else about r/SciFiConcepts
Posting rules and account requirements, how often posts get removed, who writes here (age, gender, countries), what people ask for, how they talk, and related subreddits — all in the full report.
Posts and activity for Sep 2026. Members from Reddit's subscriber counts. Read from the same data the app runs on. Our research