<p> In this dissertation, I seek to define strategies designers might use to enhance the effectiveness of their game&rsquo;s message. To do so, I adopt a rhetorical approach to impact that recognizes identification between the designer&rsquo;s view of the world and that of the player as critical to achieving impact. Based on a review of relevant literature drawn from the fields of rhetoric, interactive narrative, and game studies; interviews with prominent game designers Tracy Fullerton and Jesse Schell; case studies of <i> Undertale, That Dragon, Cancer</i>, and <i>Papo &amp; Yo</i>; and a design project creating a game to increase empathy for people with ADHD, I endeavor to present a framework for impact design that delineates major concerns relevant to the act of identification. This framework recognizes abstraction based on clearly presenting the designer&rsquo;s message and agency based on encouraging the player to engage with that message as the cornerstones of promoting impact through identification. From their intersection, I extrapolate three related design concerns: authenticity, affectivity, and ambiguity. Authenticity captures the degree to which the game rings true to both the developer&rsquo;s own beliefs as well as those of the player; affectivity describes the player&rsquo;s emotional connection to the game; and ambiguity invites players to seek their own meaning by completing the game through their act of play. Throughout my work, I expand upon these three concerns to identify how they can serve as useful heuristics for impact design, suggesting concrete strategies at the level of a game&rsquo;s mechanics, aesthetics, and narrative. I believe in the potential of games to improve people&rsquo;s lives and make the world a better place, and I see my research as contributing to that greater effort. </p><p>