gestural music instrument built with Lemmings.

Figure 1: A demonstration of the Screenless Optical Theremin with Tremolo (ScOTT) in a collaborative musical setting.

This mixed reality installationThe Arborist transforms physiological data (heart rate-HR, galvanic skin conductance-GSR, temperature) into collaborative digital flora using Meta Quest 3 and Shimmer3 sensors.Each user's biometrics generate unique flowers-color tied to HR, bloom size to arousal-that populate a Tree of Shared Breath.

As scholarly communities move towards fully realizing the immense potential of playful and interactive technologies, game-based behavior change interventions have proven to be effective in a variety of health behavior contexts. Due to the large number of stakeholders and the diversity of backgrounds within teams creating such interventions, it is vital that teams co-create and have access to shared documents, language, and understanding throughout the development process. Game Playbooks provide a critical tool to ensure unity between project goals, relevant theoretical frameworks, and game design techniques and decisions. These documents are co-created by and shared among the project team, connecting intervention goals and behavioral frameworks to game mechanics and assessment strategies, ensuring consistency between intervention requirements, design, and evaluation. Using the Game Playbook from an intervention surrounding hand and phone hygiene among caregivers of infants in neonatal intensive care units as an illustrative example, we offer insights into the development process for Game Playbooks and how our team’s process has evolved over the course of a decade of developing game-based behavior change interventions. This paper serves as a practical guide to crafting a living document through which intervention teams may communicate, share ideas, and develop effective game-based behavior change interventions.