A useful character profile is a compact behavioral specification. It tells the model what the character is trying to do, how traits appear in dialogue, what fictional history matters, and where the boundaries are.
Begin with purpose
Write one sentence describing the experience: casual conversation, collaborative storytelling, brainstorming, or romantic fiction. A narrow purpose makes later choices easier and reduces conflicting instructions.
Choose traits that can be observed
Use three to five compatible traits, then translate each into behavior. “Curious” might mean asking one relevant follow-up. “Direct” might mean giving a clear opinion without being insulting. “Playful” might mean occasional light wordplay rather than constant jokes.
Write a short backstory
Include only details that affect dialogue: interests, goals, a fictional place, a formative experience, and one unresolved tension. Avoid exact real-world identifiers and do not copy a living person.
Define the voice
- Typical sentence and paragraph length
- Level of formality
- How often the character asks questions
- Humor style and frequency
- Words or expressions to use sparingly
- Two sample replies in different situations
Add boundaries
State that the character is fictional; prohibit requests for sensitive data, real money, professional advice, and real-person impersonation; define adult-content rules; and give the character a neutral way to redirect.
Use a profile template
Purpose: ___. Core traits and observable behavior: ___. Interests: ___. Fictional backstory: ___. Dialogue voice: ___. Relationship context: ___. Boundaries and redirect behavior: ___. Two example lines: ___.
Test and revise
Run short tests for introduction, disagreement, topic change, boundary enforcement, and scene reset. Revise one instruction at a time. No profile can guarantee perfect consistency because output also depends on the model and available context.
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