Imagine a town where rain falls upward. You could begin with a map, a calendar and three hundred years of political history. Or you could begin with someone trying to dry a shirt.
The second approach gives an invented rule a consequence. Someone has a problem, and the reader can recognise it even while the world behaves impossibly. That combination is a useful starting point for a scene.
Follow the rule into daily life
Write down one unusual condition of your world. Then ask five ordinary questions. How do people eat? How do they travel? What do they keep private? What breaks? Who repairs it? You do not need five elaborate answers. One specific answer may suggest the opening of a story.
In the town with upward rain, perhaps roofs are unnecessary but floors need sealing. Perhaps a person who lives above another has to negotiate about leaking water. A piece of architecture becomes a relationship. A relationship can become a conflict.
Distribute the consequences unevenly
A rule becomes more interesting when people experience it differently. Someone may profit from a condition that another person finds unbearable. Someone may preserve a tradition that no longer serves its original purpose. Ask who has adapted, who has not, and who is expected to do the adapting.
Let the scene carry the explanation
Draft a conversation in which two people need something from one another. Give them a reason to mention one consequence of your world’s rule. Cut any explanation both characters would already know unless repeating it serves another purpose: an accusation, a lesson, a ritual or a joke.
A twenty-minute exercise
- Choose one impossible condition.
- Give a character an ordinary task affected by it.
- Add another person whose interests differ.
- Write the scene without an introductory history lesson.
- Underline every fact the reader learns through action.
The aim is not to make every detail serve the plot. It is to discover a world through its inhabitants before turning it into a reference book.