Artificial intelligence can be one of the most challenging aspects of video game development. Game AI encompasses difficult concepts such as spatial reasoning, pathfinding, movement, awareness, and decision making, all with the goal of combining these concepts into a realistic and lifelike experience for the player. It's no wonder that so many game developers put off AI development to the end of the project. This is a shame, because good AI can make or break the game experience and great AI can make a player fall in love with your game and keep them coming back again and again.

In recent years, AI has become more important than ever. Although the quality of AI in games has increased steadily over time, the results have come more from added attention and effort on the part of developers, rather than from significant breakthroughs in technology. The impact of this is that "good" AI in games has often been limited to projects and teams with large budgets and access to high-end tools. Unity changed the industry by making high-end game development tools available to all developers, big and small. Today's indie developers are creating player experiences that rival those of AAA companies. Until recently, they lacked the tools, knowledge, and know-how to add AI-driven characters that have the same fidelity as the rest of the game. Now this has changed too, with the very best AI tools becoming accessible to every developer.

This book serves an important role in the rise of AI in Unity. In these pages, you will find the guidance, techniques, and examples you need to become a great AI developer. For beginners, the book walks you step by step through the fundamentals of concepts such as pathfinding, patrolling, and creating behaviors for common scenarios such as attacking and crowd movement. You will also be introduced to the numerous tools available for Unity that you'll need along the way. For experienced developers, the book gives you access to best practices, tips, and techniques that will take you from good to great.

I'm incredibly excited about the future of AI and its potential impact on games in the coming years. Game developers are often at the forefront of innovation, and their contributions to filling the world with believable AI will be significant. Go forth, reader, and join the growing ranks of AI programmers!

Bill Klein (aka Prime)

CEO, Rival Theory