Chapter 8 — AI Cognition

Part III — Simulation Systems

How actors think.

Topics

• Beliefs — what an entity thinks is true (subject, key, value, confidence, source)
• Memories — recorded events with emotional tags and decay
• Morale — emotional state influencing behavior
• Perception input — how observed events feed into beliefs
• Intent selection — choosing actions based on beliefs and personality

The Belief Model

belief: player_hostile
confidence: 0.7
source: combat.contact.hit

AI entities act on beliefs, not objective truth. A ghoul that believes it was attacked will respond aggressively — even if the actual attacker was someone else and the ghoul only heard the noise.

Intent Profiles

Built-in profiles shape how entities choose actions:

• aggressive — prioritizes attack, low retreat threshold
• cautious — prioritizes investigation, high retreat threshold

Custom profiles can weight any combination of goals, fears, and morale thresholds.

How Cognition Connects to Other Systems

Cognition receives input from:

• perception-filter — what the entity actually observed
• environment-core — ambient conditions affecting alertness
• combat events — direct experience updates beliefs immediately

This means AI behavior emerges from the simulation rather than being scripted per encounter.

Campaign Memory

The @ai-rpg-engine/campaign-memory package extends cognition with persistent, cross-session NPC memory. While cognition-core tracks real-time beliefs and decay, campaign memory tracks long-term relationships and significant events.

Relationship Axes replace boolean hostility with four graduated dimensions:

Axis	Range	Meaning
trust	-1 to 1	Distrust → Trust
fear	0 to 1	Unafraid → Terrified
admiration	-1 to 1	Contempt → Admiration
familiarity	0 to 1	Stranger → Intimate

Memory Consolidation models how memories fade:

vivid → faded → dim → forgotten

Each NPC’s memory bank tracks salience (how important the memory is to them) and emotional charge (positive or negative). Salience decays over time; when it drops below thresholds, memories shift consolidation stages. The campaign journal persists significant events with 12 categories, enabling NPCs to reference past interactions during dialogue and decision-making.