Multi-Agent NPC Planning with Hierarchical Task Networks

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Solution Overview

Problem

Existing game development technologies face challenges in creating complex, multi-agent narratives that require significant technical expertise and are time-consuming, especially when managing interactions between multiple AI-controlled characters and players, with current AI solutions lacking efficient scripting and runtime implementation for seamless multi-agent scenarios.

Innovation Solution

A method using an authoring tool to generate a data set of transcripts that define tasks for non-player agents, transformed into a hierarchical network of tasks, orchestrated by a director component to manage multi-agent interactions, including dialogue and physical actions, leveraging HTN planning for dynamic game environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional scripting methods are used to manage multi-agent behaviors, then basic NPC interactivity can be achieved, but the system becomes extremely time-consuming and expensive to develop, requiring significant technical expertise

Engineering Contradiction:
Improveease of scripting multi-agent behaviorsVSAvoiddevelopment time for multi-agent narratives
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent introduces an intermediary planning system that sits between the game engine and NPCs, automatically generating and coordinating multi-agent behaviors. This planner translates high-level narrative goals into coordinated actions for multiple agents, eliminating the need for manual scripting of complex interactions while reducing development time and technical barriers.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system enables NPCs to autonomously plan and coordinate their own behaviors through the integrated planning system. Each NPC can independently generate plans and interact with others' plans, allowing the system to self-organize complex multi-agent scenarios without requiring external scripting for every interaction detail.

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If AI-based solutions like LLMs are used to generate game content, then more robust planning of interactivity is enabled, but the ability to efficiently script and run-time implement narratives for multi-agent scenarios is still lacking

Engineering Contradiction:
Improverobust planning of interactivityVSAvoidefficient scripting and runtime implementation
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges AI-based content generation capabilities with a formal planning system that specializes in multi-agent coordination. The system combines the adaptability of LLMs for generating narrative content with efficient algorithmic planning for runtime implementation, creating a unified solution that handles both creativity and execution efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The planning system dynamically adapts to runtime conditions by continuously monitoring game state and adjusting NPC plans accordingly. The system can generate, modify, and coordinate plans in real-time based on player actions and environmental changes, enabling efficient runtime implementation of adaptive multi-agent narratives.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple NPCs are allowed to interact with each other and the player, then more immersive game experiences are created, but the complexity of managing and coordinating their behaviors increases significantly

Engineering Contradiction:
Improvemulti-agent interaction capabilitiesVSAvoidcomplexity of managing multi-agent behaviors
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the complex task of multi-agent coordination into individual plan management for each NPC. Each agent maintains its own plan independently, and the system coordinates them through a structured planning framework that breaks down global coordination into local plan interactions, reducing overall system complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The planning system serves multiple functions simultaneously: it generates individual NPC plans, coordinates interactions between agents, adapts to runtime conditions, and manages plan revisions. This universal planning framework handles all aspects of multi-agent behavior management through a single integrated system, reducing the need for separate management mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS12403402B1Multi-agent planning system for controlling non-player agents in a game
Publication Date: 2025.09.02 BITPART AI INC
  • US12403402B1 patent drawing
  • US12403402B1 patent drawing
  • US12403402B1 patent drawing

AI summary

A method of managing a game platform. Using an authoring tool, a data set for a game narrative is generated. The data set includes transcripts that define tasks of non-player agents, such as Non-Player Character (NPC) agents, in a game session in which a player is operating under the control of a game engine. The data set is transformed into re-composable combinations of tasks structured as a multi-modal hierarchical network of tasks, wherein an individual path in the hierarchical network of tasks represents a plan that is a particular implementation of a task that having multiple ways of being implemented. During the game session, and using a director operating in association with the game engine, behaviors of one or more non-player agents are then orchestrated by receiving a set of observations occurring in the game and, in response, implementing a set of plans in the hierarchical network of tasks.