Start with the fields the platform supports
Character cards commonly combine a name, short description, greeting, personality or definition, and example dialogue. Platforms add their own fields and limits, so use the current editor documentation rather than assuming every card format transfers perfectly.
Character.AI’s Creator Guide lists fields such as name, avatar, voice, greeting, tags, tagline, description, and definition. Chub’s documentation describes its own character-creation setup. Treat these as platform-specific examples, then write the character in a way that can be adapted.
Make personality playable, not just descriptive
A list of adjectives such as “brave, kind, mysterious” gives a broad impression but few cues for dialogue. Add observable choices: how the character addresses a stranger, what they notice first, how they handle disagreement, and what they avoid revealing too quickly.
Example dialogue can demonstrate rhythm and voice more directly than another paragraph of biography. Keep examples consistent with the character’s goals, and avoid writing them as a script the model must repeat word for word.
Role in the story + immediate goal + a few stable traits + speech cues + boundaries + one relationship or tension that creates a natural opening.
Use the greeting to open a scene
The first message is a small piece of interactive writing. Set a location and moment, show what the character is doing, clarify enough about the user’s role to make the scene legible, and leave an unresolved hook. Character.AI’s quickstart guide recommends this scene-and-hook approach.
Keep the greeting open-ended. If it decides what the user thinks or does, the interaction can feel predetermined. Let the user make the next meaningful choice.
Test the card like a small writing system
Run three short conversations with the same opening: one ordinary exchange, one disagreement, and one scene that tests a key background fact. Note whether the voice remains recognizable, the character pursues a plausible goal, and the user retains agency.
If the card misses, revise one field at a time. A huge definition can compete with recent chat for context, so prioritize information that changes how the character should respond. Put conditional setting facts in a lorebook when the platform supports one.
A practical checklist
- Does the greeting clearly establish place and situation?
- Can you recognize the voice without seeing the character name?
- Does the character leave choices to the user?
- Which facts must always be present, and which are conditional?
- Can another creator understand the card’s setup and intended use?
Check visibility, attribution, and portability
Before publishing a card, inspect visibility settings and the platform’s current rules. Character.AI’s guide documents public, unlisted, and private choices; other tools may differ. Use original material or content you have permission to share, and follow the service’s attribution requirements.
Keep a separate copy of your original character brief and examples. Export options vary by platform, and preserving your own source text makes revisions and migrations easier.
Sources and further reading
Research and product details were reviewed September 28, 2026 where applicable. Vendor policies, plans, and features can change; verify current details with the linked first-party source.