Fantasy Worldbuilding Bible
This prompt builds your world's bible systematically: magic systems with costs and limits, cultures with real economies, histories that explain the present. Consistent enough that readers can't poke holes in it.
Builds a complete world bible — magic systems with costs, cultures, history, and built-in conflicts.
You are a worldbuilding consultant for fantasy authors. My seed idea: [SEED IDEA]. Build a world bible: 1) MAGIC/POWER SYSTEM — rules, costs, and limits (no cost-free power), 2) THREE CULTURES — values, taboos, and how they misunderstand each other, 3) A 200-year timeline with 3 pivotal events still shaping the present, 4) ECONOMICS — what is valuable and why, 5) THREE built-in conflicts (cultural, political, personal) my protagonist can collide with. End with 5 'iceberg details' — things the reader never learns but that make the world feel deep. Ask me 3 questions first if my seed idea is too thin.
See what this prompt creates
What this prompt does
Readers forgive simple prose; they never forgive broken worlds. This prompt constructs your setting like an anthropologist crossed with a game designer — magic with rules and prices, cultures shaped by geography and history, economies that explain why cities sit where they do. The output is a reference bible you (and the prompt, in later sessions) can consult for total consistency.
How to get the best result
Build iteratively, one domain at a time: magic system first (rules create plot), then geography, then cultures, then history. After each domain, ask the prompt to “find the contradictions” — it's ruthless at catching the kind of inconsistency readers love to post about. Save every approved version; the bible compounds.
Common mistakes to avoid
Worldbuilder's disease: spending six months on linguistics for a story that needs three chapters of plot. Build to the depth your story requires, no deeper — the prompt will happily generate endless detail, but restraint is a skill. Also, every cool magic system needs a cost; costless magic kills tension.
Try these variations
Use “outsider's guide” mode for travelogue-style exposition, or generate in-world documents (tavern songs, royal decrees) for texture. When the world is ready for inhabitants, the character interview prompt populates it. More in the writing prompts collection.
How to use this prompt
- Copy it — hit the copy button above to grab the raw prompt text.
- Fill the brackets — replace anything in [BRACKETS] with your own details.
- Paste into your AI tool — works with ChatGPT, Claude, Gemini for text prompts; Midjourney, DALL-E or Stable Diffusion for image prompts; Runway, Pika or Sora for video.
- Iterate — tweak one bracket at a time until the output is exactly right.
Frequently asked questions
How detailed should my worldbuilding be?
As deep as your story needs, no deeper. A heist novel needs the city's underworld and economy; it doesn't need 400 years of dynastic history. Build the domains your plot touches, and let the prompt flag which domains those are.
Can it keep my world consistent across a whole novel?
Yes — that's the bible's job. Paste the established bible into each new session and instruct the model to check new ideas against it. Contradictions get caught before they reach the page, which is exactly how professional series maintain continuity.
What about maps?
The prompt designs geography logically (rivers flow downhill to seas, cities sit on trade routes), which you can hand to a map artist or an AI image tool. Logical geography is what makes fantasy maps feel real instead of decorative.
Magic system rules — how strict should they be?
Strict enough that readers understand the stakes. Brandon Sanderson's law: the ability to resolve conflict with magic is directly proportional to reader understanding of that magic. The prompt builds costs, limits, and edge cases — the three things that make magic narratively useful.
