Roleplay system prompts

The system prompt is the most important setup for getting good roleplay from an AI. It tells the AI what kind of writing you want, how fast the story should move, how much detail to use, and which rules should apply to every reply.

Museris includes a basic default system prompt, so you can start right away. Write your own when you want roleplay that better fits your story, characters, and tastes. The system prompt works with your characters, lore, and chat instruction. It should guide the writing, not repeat every fact about the scene.

Start with the result you want

Be clear about the experience you want instead of using broad labels like “be creative.” A good system prompt often covers:

• Writing job: Write one in-character roleplay reply.
• Style: Choose a mood, point of view, length, and level of detail.
• Perspective: Say whether the AI should write in first person or third person.
• Formatting: Say how dialogue, thoughts, actions, or other text should look.
• Pacing: Say whether you want the story to take its time or move quickly.
• Player agency: Tell the AI not to speak or act for your character unless you ask it to.
• Focus: Name what matters most, such as dialogue, action, emotion, mystery, romance, or world detail.

For example, you might write:

Write in third person. Put spoken dialogue in quotation marks and actions in asterisks.

You could instead ask for first-person replies, thoughts in asterisks, or plain prose with no special formatting. Pick one clear style and use it throughout the chat.

Set the mood and level of detail

You can use the system prompt to ask for the kind of storytelling you enjoy. State what you want in plain words:

Keep the writing warm, character-focused, and emotionally honest.
Let conversations unfold naturally instead of rushing to the next plot point.
Describe meaningful reactions and physical details when they fit the scene.

For more personal, romantic, frightening, or intense scenes, name the tone and detail level you want. You can also say what should stay off-screen, be handled gently, or be avoided. Clear direction helps the AI match your comfort level and your story's mood.

Put each kind of detail in the right place

Use the system prompt for rules that should apply throughout the roleplay. Keep other details where they are easiest to reuse and change:

Put it here	Use it for
System prompt	Writing style, response length, pacing, player agency, and general content limits.
Character definition	Personality, history, relationships, goals, and character-specific voice.
Lorebook	World facts, locations, factions, history, and other shared setting details.
Chat instruction	Specific instructions for a single chat.

This keeps the prompt easier to understand. It also means you can reuse the same character in stories with different styles and moods.

Keep it short, then improve it

Start with a few strong directions. Long lists of repeated rules can make the result less reliable.

Test the prompt by editing it, then using Regenerate Message to make a new swipe of the latest AI reply. This lets you compare the old and new results in the same scene. If it is not giving you what you want, change one part at a time. For example, ask for shorter replies, slower pacing, more dialogue, or clearer attention to a character's feelings. Small changes make it easier to learn which direction helped.