50 World Building Prompts for Creating Planets and Moons

These world building prompts come from 3000 World Building Prompts, which you can get at Amazon. This section is focused on creating planets and moons, including habitable ones.

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  1. What is the name of the galaxy?
  2. What is the solar system’s name?
  3. Are there any comets and how often do they appear?
  4. Is there an asteroid field?
  5. If so, in between which planets is it found?
  6. How hard is it to pilot through it?
  7. Are there any destroyed planets in this system?
  8. If so, is the planet in pieces?
  9. Or is just devoid of livable conditions now?
  10. What kind of sun (yellow, red dwarf) is at the system’s center?
  11. Is it a binary star system?
  12. How many planets are in the solar system?
  13. Which planet are you creating (nearest, farthest, fourth)?
  14. Does the planet have a ring system (like Saturn)?
  15. Is the atmosphere breathable?
  16. Is this a rocky, icy, or gaseous planet?
  17. How many seasons are there and how often do they occur?
  18. Is the planet in a retrograde orbit of the sun?
  19. Does the planet rotate clockwise or counterclockwise?
  20. Are there other planets in the solar system?
  21. What do they look like to the naked eye from this planet, if they can be seen?
  22. How many planets are in the sun’s habitable zone?
  23. Can other planets be seen with the naked eye?
  24. Can other planets be visited via magic or technological means?
  25. Are any constellations important in your setting?
  26. Which constellations are visible in each hemisphere?
  27. Are there are dark constellations?
  28. Are there constellations associated with months, like astrological signs?
  29. Is this planet bigger or smaller than Earth and by how much?
  30. Has global warming occurred and to what degree?


  1. How many moons are there?
  2. Are any of the moons tidally locked?
  3. Is the planet and one moon tidally locked to each other?
  4. Are any moons in a retrograde orbit?
  5. Are any moons barren?
  6. Are any moons icy?
  7. Are the tides the moon(s) cause bigger, smaller, or the same as on Earth?
  8. How many moons are causing the tides? If more than one, how often do the biggest tides occur?
  9. Are there any conjunctions of moons, planets and the sun(s) and how often do these occur?
  10. Are any moons habitable? Which ones?

Habitable Moons

  1. Is the world you’re creating right now a moon?
  2. If so, what effect(s) does the planet have on it?
  3. How often does the planet cast its shadow over the moon in a penumbral eclipse?
  4. In a total lunar eclipse?
  5. In a partial lunar eclipse?
  6. How dark does it get during each of these eclipse types?
  7. For how long does this occur?
  8. Are there any natural events that take place then, such as creatures who only come out at that time?
  9. How does this impact sentient life on the moon?
  10. Are there any rituals or protections people plan for and make?
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