Game AI is at a turning point.
For decades, NPCs have followed scripts-predictable, brittle, and ultimately lifeless. But a new paradigm is emerging. One where characters don't just react... they reason.
Building Agentic AI in Unity takes you inside that shift.
This book explores how to design and implement truly autonomous NPCs by combining local large language models with reinforcement learning-entirely offline, fully under your control. You'll learn how to replace rigid state machines with goal-driven agents that think strategically, act fluidly, and adapt to unpredictable player behavior in real time.
Rather than relying on cloud APIs or black-box solutions, this guide walks you through a clean, production-ready architecture that runs directly inside Unity. Strategy and execution are separated. Intelligence and performance coexist. And every system is built with scalability, cost control, and long-term viability in mind.
This isn't about hype. It's about building AI that feels alive-using tools you can ship.
KEY FEATURES- Offline, local AI using Llama 3-no cloud dependency
- Agentic architecture that separates reasoning from execution
- Deep Unity integration with ML-Agents and Sentis
- Practical C# implementations, not theory
- Real-time NPC decision-making with structured intent
- Local memory systems using RAG and embeddings
- Performance-aware design for real shipping games
Most AI books stop at concepts or rely on remote services that don't scale for games. This book is different. It shows how to own the entire stack-from local inference and memory to real-time movement and decision execution-inside Unity. The result is a future-proof approach to game AI that is cost-effective, offline-capable, and designed for modern production realities, not demos.
Who This Book Is ForThis book is written for Unity developers, technical game designers, and AI-curious engineers who want to move beyond scripted behavior and build systems that genuinely think. If you're comfortable with C#, interested in modern AI, and serious about creating believable NPCs that can ship in real games, this book was built for you.
What You'll Gain- Design goal-driven, agentic NPC architectures
- Run Llama 3 locally inside Unity
- Combine LLM reasoning with ML-Agents execution
- Eliminate cloud costs and online dependencies
- Build NPCs that adapt, plan, and remember
- Create AI systems that scale to production
- Future-proof your game AI skillset