Tell it who to be
Role prompting assigns the model a persona, such as a patient tutor or a strict reviewer. The role shifts tone, vocabulary, and the level of detail, because it conditions the model on a slice of text where such a speaker would appear.
What a role controls
- Tone and register, from casual to formal.
- Vocabulary, steering toward plain words or domain terms.
- Depth and assumptions about what the reader already knows.
- Stance, such as skeptical, encouraging, or neutral.
Use it for style, not facts
A persona reliably changes how something is said. It does not reliably add knowledge the model lacks, and claiming an expert role does not guarantee correct expertise. Treat it as a style and framing knob, paired with real context for facts.
Keep it specific
Vague roles do little. A precise persona with audience and goal, such as explain to a beginner who fears math, steers far more than a bare label like expert.
Key idea
Role prompting conditions the model on a persona to control tone, vocabulary, depth, and stance, a reliable style knob that should be specific and paired with real context for facts.