# Languages and rules, how the AI behaves

Source: https://lunafic.ai/docs/rules-and-ai-behavior | Published: 2026-10-07T03:33:36.471Z | Updated: 2026-10-07T04:55:12.672Z | Author: Lunafic Team | Tags: Create a Playable World

> Set the languages of the world, and write the rules the AI follows on every reply.

This step tells the AI how your world behaves. Rules you write here are passed to the AI as high-priority instructions on every reply, and the AI has to follow them.

## Languages

At the top you set the character language, the narrative language, and the dialogue format, the same three dials every story uses. They save as you go.

[The three dials are explained here.](/docs/narrative-settings)

## Rules of the world

Rules are the things that always happen here. Players cannot break them and the AI does not forget them. Each rule has a title, up to 240 characters, and an optional detail, up to 240 characters.

For example, The rain never stops after midnight. If you are out of ideas, the step suggests starters like Magic has a price, No one dies in this city, and The last train is a rumor.

You need at least one rule to release.

## Write rules that get obeyed

- Write them as commands. **One sentence each.**
- Keep them few. **Five rules the AI obeys are worth more than twenty it ignores.**

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Read this on Lunafic: https://lunafic.ai/docs/rules-and-ai-behavior
More from Lunafic: https://lunafic.ai/docs
What is Lunafic: https://lunafic.ai/ai-roleplay
AI characters you build stories with over long memories. You play as your character, the AI plays everyone else, and stories stay private by default.