Chapter 43. Emergent Complexity

Key Topics

• A Definition of Emergence

• Emergent Behaviors

• Smarter Environments, Simpler Behaviors

• Emergence in Functionality

Emergence is a particularly popular topic in both the artifi cial intelligence (AI) and game-development communities. Emergent phenomena are particularly interesting yet somewhat mystical. AI researchers are keen to capture emergence properties to improve their intelligent systems, and designers are keen to increase the entertainment of their games.

As game AI developers, our interests lie in producing more efficient nonplayer characters (NPCs) with simpler techniques and producing more interesting behaviors. The combination of the emotional system with intelligent capabilities—generating fascinating scenarios—is a good example of an emergent system. We want to understand and reproduce such phenomena.

This chapter covers the following topics:

• The concept of emergence, its intricacies, and the different types of emergent patterns.

• The most popular example of emergence in games: behaviors at the individual and the collective level

• One particularly popular form of emergence that involves smart environments providing functionality to simple AI creatures

• The emergence of functionality as the general case, and various techniques from AI and modern software engineering to harness the power of chaos

First, a clarification of the concept of emergence is in order.