Keep Calm and Aim for the Head: Biofeedback-Controlled Dynamic Difficulty Adjustment in a Horror Game

Who said that violent video games cannot promote calm behavior? Could we reverse engineer the difficulty system of a horror game to encourage the player to stay calm as opposed to feeling under constant pressure? To explore the feasibility of the approach and its effectiveness, we created a horror game,Caroline, which uses the player’s biometric data to adapt the difficulty of the game: if the player is too stressed, the difficulty increases, and the opposite happens if the player is relaxed. We explored the effect of such an approach on players’ cognitive, emotional, performative, and decision-making challenge as well as their intrinsic motivation by comparing it to the base game without any dynamic difficulty adjustment (DDA). Our results showed that players felt more motivated when the gameplay was adjusted according to their heart rate. However, out of the four types of challenge, the only one affected by the DDA was the decision-making challenge. We discuss what these findings mean for video game design and research into affective computing and provide suggestions for future research.