System Prompt Examples

# System Prompt Examples & Best Practices

This page belongs to the [System Prompt Workspace](../basic/system-optimization.md).

It answers one question:

**what kind of content is best written into a system prompt.**

## First rule of thumb

If your goal is to answer questions like these, system prompt mode is usually a good fit:

- who should the model behave as?
- which long-lived rules should always apply?
- what must never happen?
- should the output structure stay fixed?

If your goal is only “write an email” or “summarize this text”, user prompt mode is usually better.

## Pattern 1: role + rules + boundaries

### Basic version