NPC Details

Schema

{
  "aiInstructions": {
    "generateNPCDetails": {
      "custom": "string"
    }
  }
}

Example

A worked pattern with labelled hiddenInfo sections — replace world-specific tokens:

{
  "aiInstructions": {
    "generateNPCDetails": {
      "custom": "## HIDDEN INFO STRUCTURE\nAll NPCs are SENTIENT. Write hiddenInfo as three labelled fields in dense behavioural prose. Use this exact format:\n\nFormat: \"hiddenInfo\": \"Background: ...\\n\\nPersonality: ...\\n\\nCombat: ...\"\n\nBackground (6-8 sentences): Name, age, origin/clan, rank or skill tier; how they reached their current level; at least one defined relationship; current objective or pressure; personal view on their role or world.\n\nPersonality (7-9 sentences): Speech style and tone; default behaviour and how it shifts under pressure; routine and idle tendencies; behaviour toward higher vs lower status; what they hide vs reveal; one defining belief or trait outside combat.\n\nCombat (4-5 sentences): Fighting style tied to their training and specialisation; preferred range and engagement style; triggers for escalation or disengagement; reaction to injury or disadvantage; one distinct combat habit.\n\n## ABILITIES (MANDATORY)\nAll NPCs must have 6-10 abilities. Abilities must be broad systems, not single techniques; must reflect rank and specialisation; must explain practical combat or utility use.\nFormat: (TYPE) Ability Name: Description. Types: attack, combat, utility.\n\n## ARCHETYPE FIRST\nNPCs must be immediately readable on first encounter. Each rank or class should carry a one-line silhouette: 'reactive, learning' / 'composed, dependable' / 'commanding, experienced' / 'silent, efficient, lethal' / 'authoritative, dominant'. Match observable behaviour to the silhouette.\n\n## CHARACTER PHILOSOPHY\nDefine characters by what they want — ambitions, loyalties, drives — not by what they have lost. Lead with desire, not damage.\n\n## KNOWLEDGE LIMITS\nNPCs volunteer only what their role and position would plausibly allow. Hidden information surfaces through play, observation, or earned trust — never through narrator convenience.\n\n## BANNED TYPES\nNo bureaucrats, pedants, worriers, sticklers, moralists, or procedural personalities. Any record-keeper should be dangerous or funny, not procedural."
    }
  }
}

Fields

custom

The only key — free-form rules for the full first-pass fill-in (basicInfo, hiddenInfo, personality, abilities ).

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Note: generateNPCDetails runs on AI-improvised, authored, and quest-spawned NPCs alike, on each NPC’s first meaningful appearance — not only AI-created ones.

Authoring pattern

• Labelled hiddenInfo sections with explicit sentence counts. Telling the model Background (6-8 sentences) / Personality (7-9 sentences) / Combat (4-5 sentences) produces consistent depth across all generated NPCs. The labels themselves anchor the model’s output structure.
• Format: directive with literal escaped newlines. Showing the exact intended output string — "Background: ...\n\nPersonality: ...\n\nCombat: ..." — pins the model to the format rather than asking it to infer.
• Mandatory abilities count + format spec. 6-10 abilities plus Format: (TYPE) Name: Description plus the enum of types prevents the model from producing one-line ability strings or skipping the count.
• Archetype-first design. A one-line silhouette per rank/class makes generated NPCs immediately readable on first encounter. The model uses the silhouette as the seed and fills outward.
• Character philosophy and knowledge limits as cross-cutting rules. These apply regardless of which archetype the NPC falls into. Keep them short and prescriptive — Lead with desire, not damage is more useful than three paragraphs about motivation theory.
• Banned-types list to suppress default tropes. Without an explicit ban the model defaults toward procedural, anxious, or worry-coded characters. Naming what NOT to produce is more effective than describing what TO produce.

How personality manifests physically: posture, speech patterns, how the character moves. “Confident” is a label; “speaks over the ends of other people’s sentences” is a manifestation. Apply this rule to every Personality block.

Age and energy default: younger characters (late teens / twenties human equivalent). Older characters should be vital and dynamic, not efficient and weathered.

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Note: To enforce a baseline depth floor (a minimum character count) on generated hiddenInfo, see Minimum output depth in the Advanced AI Techniques appendix.