Chapter 3. Reactive Approach

Key Topics

• Definitions

• Behaviors: Planning Versus Reactive

• Reactive Techniques in Game Development

• Architectures

The AI techniques and behaviors used in this book share a common trait: They are all reactive components. The reactive approach is ideally suited to computer games because it's so simple and efficient. The predictability is also a tremendous advantage for design and testing. Contrary to popular belief, mostly reactive systems can be made to be extremely competent, rivaling approaches based on planning. This chapter shows how to achieved this in the design of the AI system, combining reactive components together.

This chapter covers the following topics:

• The definition of the term reactive, in mathematical and practical terms

• The difference between reactive techniques and planning, and two different approaches to solving similar problems

• The numerous benefits of reactive AI in games

• Reactive architectures that combine reactive behaviors and techniques

Reactive techniques are the most successful in the field of AI and have been demonstrated in a great majority of computer games. Before this discussion turns to the benefits and pitfalls of this approach, we need to understand the capabilities of reactive AI.