This article focuses on the development and initial validation of the game-based psychodiagnostic tool “Architecture of Mindscapes”, designed to assess decision-making strategies. The primary focus is on developing a game-based tool to address the limitations of J. Bruner’s classical framework for studying decision-making strategies and on identifying quantitative indicators that characterize various decision-making strategies. The study involved 50 participants aged 15 to 23 years (M = 18.7; SD = 2.73), enrolled in various educational levels and fields. The data were processed using descriptive statistics, the Kruskal–Wallis H-test, and cluster analysis (Ward’s method). The analysis identified four strategy groups. The “Simultaneous Scanning” strategy is characterized by the fewest moves and hypotheses, while maximizing the time spent on their evaluation. Participants using the “Conservative Focusing” strategy demonstrated performance metrics close to the average. The “Successive Scanning” strategy was characterized by the highest number of moves and hypotheses, while the “Focus Gambling” strategy was associated with the shortest completion time and the shortest decision-making time. These results provide a foundation for further analysis of the dynamic characteristics of decision-making strategies, aiming to enhance the validity of the diagnostic tool.