Modern professional networking relies on social media. To take advantage of this fact, we present CHI PLAY-GUE, a conference game designed to facilitate interaction among strangers and encourage social networking to create a community. The game integrates digital technology (mobile devices and large displays) within the space of the conference venue, combined with a mixed-reality narrative and people's social interactions to facilitate the emergence of social dynamics. By providing a platform for large-scale, playful interaction, the game creates an experience that fosters the development of mutually beneficial, personal, and professional relationships among players.