ABSTRACT
Utility theory offers a powerful and compelling model for game AI. In a nutshell, available decisions are scored using some mathematical formulas, and the agent selects a course of action from among the best-scoring options. There are several available models for utility-based architectures described in existing literature and lectures. The specifics of building decision-making systems are often left as a proverbial exercise to the reader, often with vague allusions to "game-specific" details. This chapter explores some of the specific details, taking a tour of some of the decisions available to nonplayer characters (NPCs) in Guild Wars 2: Heart of Thorns. Each decision will be broken down into the considerations that affect whether or not the decision is considered optimal at any given point in time. The chapter focuses on the rationale for choosing each specific consideration. It concludes with a series of general-purpose tips that can be applied to consideration selection in any utility-based architecture.
