2nd/10_Wiki/Topics/AI_and_ML/Procedural Narrative Generation.md

id, title, category, status, canonical_id, aliases, duplicate_of, source_trust_level, confidence_score, verification_status, tags, raw_sources, last_reinforced, github_commit, tech_stack

id	title	category	status	canonical_id	aliases	duplicate_of	source_trust_level	confidence_score	verification_status	tags	raw_sources	last_reinforced	github_commit	tech_stack
wiki-2026-0508-procedural-narrative-generation	Procedural Narrative Generation	10_Wiki/Topics	verified	self	PNG Story Generation Computational Narrative Drama Management	none	A	0.85	applied	narrative generative-ai games llm-applications		2026-05-10	pending	language framework Python / TypeScript LLM (Claude/GPT) + planner / state machine

Procedural Narrative Generation

매 한 줄

"매 algorithmic story authoring — symbolic planners 부터 LLM-driven emergent narrative 까지". 1970s TaleSpin / 1990s drama managers (Façade) 의 lineage; 2019 AI Dungeon 으로 LLM era 시작, 2024-2026 currently agent-based simulation (Smallville, Voyager, Genesis) 에서 narrative emerges from LLM agents interacting in worlds. Hybrid 가 winning: LLM creativity + symbolic constraints.

매 핵심

매 paradigm timeline

• Story grammars (1970s-80s): Propp's morphology, Rumelhart, TaleSpin (Meehan 1977).
• Planning-based (1990s-2010s): STRIPS planners author plot (IPOCL, MEXICA).
• Drama management (2000s): Façade (Mateas & Stern 2005) reactive narrative.
• Neural (2017-2020): GPT-2/3 generated stories, Plug-and-Play LMs.
• AI Dungeon era (2019-): open-ended LLM-driven IF.
• Agent simulation (2023-2026): Park's Smallville, Voyager, Genesis world model — believable agents whose interactions form narrative.

매 challenges

1. Coherence: long-range plot consistency (LLMs forget).
2. Causality: events must causally connect.
3. Character agency: characters with goals/personalities, not just templates.
4. Author's vs character's intent: meta-level narrative goals vs in-world goals.
5. Tellability: not every simulation is a good story.

매 modern hybrid stack

• World model: structured state (locations, items, NPCs, relationships).
• LLM as narrator: takes state + recent events → next beat.
• Symbolic planner: enforces causal constraints, beats arc.
• Memory / retrieval: vector DB of past events for consistency.
• Drama manager: monitors arc (rising/falling tension), nudges plot.

💻 패턴

LLM beat generator with state

def generate_beat(state, history, beat_target):
    prompt = f"""You are a narrator. Current state:
Characters: {state.characters}
Location: {state.location}
Inventory: {state.inventory}
Recent events: {history[-5:]}

Beat target: {beat_target}  # e.g., "rising tension", "reveal villain"
Generate the next narrative beat (2-3 sentences) and any state changes as JSON."""
    resp = claude.messages.create(
        model="claude-opus-4-7",
        max_tokens=400,
        messages=[{"role": "user", "content": prompt}],
    )
    return parse(resp.content[0].text)

Story-arc drama manager (Freytag)

ARC = ["exposition", "rising_action", "climax", "falling_action", "resolution"]

class DramaManager:
    def __init__(self, n_beats=20):
        # Map beat index to arc stage
        self.targets = ([ARC[0]] * 3 + [ARC[1]] * 8 + [ARC[2]] * 2
                        + [ARC[3]] * 4 + [ARC[4]] * 3)

    def next_target(self, beat_idx, tension_so_far):
        target = self.targets[beat_idx]
        if target == "rising_action" and tension_so_far < 0.3:
            return "rising_action_inject_conflict"
        return target

Goal-based character agent

class CharacterAgent:
    def __init__(self, name, traits, goals):
        self.name, self.traits, self.goals = name, traits, goals
        self.memory = []  # recent observations

    def choose_action(self, world_state):
        # LLM call: given personality + memory + state, pick action
        prompt = f"""You are {self.name}. Traits: {self.traits}.
Active goals: {self.goals}.
Recent: {self.memory[-10:]}.
World: {world_state}.
What do you do next? Output: action(target, args)."""
        return llm(prompt)

Causal consistency check

def verify_beat(beat, state):
    """Reject beats that violate world rules."""
    issues = []
    for change in beat.state_changes:
        if change.kind == "use_item" and change.item not in state.inventory:
            issues.append(f"{change.item} not in inventory")
        if change.kind == "location" and change.to not in state.adjacent_locs:
            issues.append(f"non-adjacent move {state.location}->{change.to}")
    return issues  # caller re-prompts on issues

Memory-augmented retrieval (Smallville-style)

def retrieve_relevant(query, memory_db, k=5):
    """Score = recency + importance + relevance (cosine)."""
    now = time.time()
    scored = []
    for m in memory_db:
        recency = 0.99 ** ((now - m.t) / 3600)
        relevance = cosine(embed(query), m.embedding)
        score = recency + m.importance + relevance
        scored.append((score, m))
    return [m for _, m in sorted(scored, reverse=True)[:k]]

Branching narrative (interactive fiction)

def turn(state, player_input):
    candidates = generate_n_continuations(state, player_input, n=3)
    chosen = drama_manager.pick(candidates, state.arc_position)
    state = apply(state, chosen)
    state.history.append(chosen)
    return state, chosen.text

Constrained generation w/ JSON schema

schema = {"type": "object", "properties": {
    "narration": {"type": "string"},
    "state_changes": {"type": "array", "items": {...}},
    "tension_delta": {"type": "number", "minimum": -1, "maximum": 1},
}, "required": ["narration", "state_changes"]}
# Use response_format=json_schema with Claude / GPT-5

매 결정 기준

상황	Approach
Short interactive story	Pure LLM w/ state in prompt
Long campaign (RPG)	LLM + structured world DB + retrieval
Strong authorial intent	Planner + LLM surface text
Emergent simulation	Agent-based (Smallville pattern)
Branching narrative game	Drama manager + tree-of-beats

기본값: LLM beat-generator + structured world state + drama manager + retrieval memory.

🔗 Graph

• 부모: Computational-Narrative · Generative-AI
• 변형: Interactive-Fiction · Drama-Management
• Adjacent: Large-Language-Models · Planning

🤖 LLM 활용

언제: games (RPG, IF), creative writing tools, simulation, training data for narrative tasks. 언제 X: factual reporting, deterministic content (ads/legal), regulated medical/legal narration.

❌ 안티패턴

• Pure LLM, no state: forgets at chapter 3, introduces dead characters.
• Planner-only, no LLM: prose feels mechanical.
• No drama curve: flat tension → boring.
• Unbounded creativity: LLM invents items/locations with no consistency check.
• Single-shot 100k-token story: better as iterative beats with state.

🧪 검증 / 중복

• Verified (Park et al 2023 Generative Agents UIST, Mateas & Stern 2005, Riedl & Bulitko 2013 survey).
• 신뢰도 A (theory) / B (rapidly evolving practice).

🕓 Changelog

날짜	변경
2026-05-08	Phase 1
2026-05-10	Manual cleanup — full PNG history + 2026 hybrid LLM/agent stack