This document discusses cognitive strategy and flow theory for game design. It explains that cognitive strategy refers to how people solve problems using reasoning, planning and other mental processes. The document then outlines Mihaly Csikszentmihalyi's flow theory, which describes an optimal state of intrinsic motivation where people are fully immersed in an activity. It provides a 4-step approach to applying flow theory to game design: setting goals, engaging the player, providing feedback, and removing distractions. The conclusion states that considering cognitive flow strategy is essential for creating a successful game.