The goal of this book is to get readers who are new to game AI to the point where they can usefully consume “regular” books on game AI. It is aimed at those who do not have a hard-core programming background, particularly those coming from other areas of game development. The book achieves this through a series of projects based on small and understandable games. Because AI is about decision making, the projects and topics selected for the book are measured against the question, “Can a beginner understand the decision-making process?” The projects may present some challenges, but with the help of this book, beginners should always be able to say, “I might have trouble getting the AI to act, but I have no trouble getting the AI to decide.”

The very basics of game AI are covered in the first three chapters of the book. Chapter 1, “What Is Game AI?” introduces game AI and Visual Studio. Chapter 2, “Simple Hard-Coded AI,” covers the simplest AI method of all. Chapter 3, “Finite State Machines (FSMs),” is about one of the simplest formal structures for AI, finite state machines. These chapters provide grounding in the most basic of AI techniques, but they should not be overlooked as these techniques are very widely used in game AI.

More-sophisticated techniques begin with Chapter 4, “Rule-Based Systems.” Chapter 5, “Random and Probabilistic Systems,” covers computing odds on the fly and random-selection decision making. Planning is introduced in Chapter 6, “Look-Ahead: The First Step of Planning.” The next step in planning, pre-planning, is covered in Chapter 7, “Book of Moves.” A relatively new topic for game AI is covered in Chapter 8, “Emergent Behavior.” Chapter 9, “Evoking Emotions on the Cheap,” opens the topic of emotions, keeping the material at an introductory but still useful level. Finally, Chapter 10, “Topics to Pursue from Here,” wraps things up with a look ahead at more sophisticated AI techniques that are beyond the scope of this book.

The projects use the Microsoft Visual Basic programming language. The Express Edition of VB is a free download from Microsoft. While most professional AI code is written in C++, VB is less threatening to people who do not have a hard-core programming background. Students, artists, animators, managers, and even producers who need to take their first steps in game AI should find the language easy to work with. All the code is included on the CD, which can save you a great deal of typing. If your typed-in code is not working, just consult the code on the CD. All the code for the projects is also included in the text of this book; if you lose the CD, you can still do all the projects.