Breaking Players' expectations: the Role of Non-player Characters' coherence and Consistency

2025-12-08

AI Summary

This study investigates how coherence and consistency in NPC design dynamically modulate player expectations and cognitive-affective evaluations. Two controlled experiments were conducted using a military first-person shooter, systematically manipulating two factors: (1) appearance–behavior congruence (congruent vs. incongruent) and (2) behavioral logic (coherent vs. incoherent), while collecting multimodal data—including self-reports, behavioral logs, and physiological measures (e.g., skin conductance response). Results demonstrate that coherent and congruent NPC designs significantly enhance perceived credibility and intelligence, whereas incongruent designs—though potentially useful for narrative tension—consistently impair intelligence attribution and acceptance. The key contribution is the first empirical identification of the “expectancy violation” effect as a double-edged sword: its valence and magnitude depend critically on the interaction between coherence and congruence. This yields a quantifiable cognitive mechanism model and a practical design framework for human–NPC interaction. (149 words)

Technology Category

• Humans and AI: Game Design — Virtual Humans, NPCs and Autonomous Characters
• Cognitive Modeling & Cognitive Systems: Social Cognition And Interaction
• Knowledge Representation and Reasoning: Preferences

Application Category

• User Modeling, Personalization and Recommendation: Metrics for user behavior and evaluating success
• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• Economics, Online Markets and Human Computation: Trust and reliance of crowd workers and data experts on GenAI

Abstract

In video games, non-player characters (NPCs) play a pivotal role in shaping players' experiences. The design of these characters, encompassing their appearance and behaviors, can be manipulated in terms of coherence and consistency to maintain players' expectations or, on the contrary, to surprise them. The extent to which NPCs' coherence and consistency influence players' evaluation of them remains to be unveiled. To address this knowledge gap, two experiments were conducted in the context of a military shooter game. Players' evaluations of NPCs' perceived intelligence and believability were measured, as these two dimensions are fundamental to players' adoption of NPCs and subsequent commitment to them. The first experiment investigated the impact of disrupting players' initial expectations on their evaluations of NPCs. The second experiment focused on the influence of NPCs' coherence and consistency on both players' expectations and evaluation of NPCs, using a combination of questionnaires and behavioral and physiological measures. The results of our study show that disrupting players' initial expectations influences their assessment of NPCs, with coherent and consistent design reinforcing expectations and incoherent design challenging them.

Problem

• Investigates how NPC coherence and consistency affect player expectations
• Examines impact of breaking player expectations on NPC evaluation
• Measures player perception of NPC intelligence and believability

Innovation

• Manipulating NPC coherence and consistency to shape player expectations
• Using behavioral and physiological measures to assess NPC perception
• Disrupting initial expectations to influence NPC intelligence and believability evaluations