Afflict is a Half-Life 2 mod created for my senior thesis in Cognitive Science: Affective Gaming: Integrating Psychophysiology and Interactive Games. The project spanned eight months, with five months of research followed by three months of development. It concluded with a semi-functional prototype, a comprehensive report and a final presentation.

Afflict is a first-person puzzle game in which players’ emotional responses fundamentally affect the game experience. Heart rate and skin conductance become new input channels, alongside the keyboard and mouse. Afflict’s responses to player physiology are grouped into three categories: Perceptual, Intentional, and Stealth.

Perceptual: As emotions shift, subtle effects across graphics, sound and control take hold. For example, increased arousal introduces distortion to the ambient soundtrack. Decreased arousal reduces shadows and tints the screen blue. These low-level variations achieve a cumulative effect, establishing an emotional bond between player and game.

Intentional: At times, Afflict is explicit about what affective states its detects and desires. Players can then manipulate their emotions to achieve strategic goals. For example, certain doors can only be opened by increasing one’s arousal for three consecutive seconds.

Stealth: Player arousal immediately affects the sensing abilities of enemy AI. The player must remain calm to move undetected. Because the player’s strategic goals (stealth) are often at odds with their emotional states (stress), this dynamic can dramatically affect the experience.

The project spanned eight months, with five months of research followed by three months of development. It concluded with a semi-functional prototype, a comprehensive report, design specifications and a final presentation.

With Afflict, I asked how game design could respond to affective computing. This remains an open question. Given accurate emotional readings, how should the system respond? Should the game become easier with high arousal? Or should it accelerate to fuel the player’s excitement? These complex feedback loops continue to present fascinating design challenges.