While online virtual worlds draw increasingly wider audiences of players and scholars alike, offline games continue to evolve into more complex and socially layered forms as well. This dissertation argues that virtual worlds need not exist as online, digital environments alone and probes three genres of non-digital gaming for evidence of the virtual: tabletop role-playing games, murder-mystery events, and localized alternate reality games. More broadly, then, this dissertation is about deliberate make-belief: practiced by adults, taken seriously by participants, engaged with for long hours at a time, performed in public, and integrated into everyday social relationships. Drawing on scholars who study games as social activities (McGonigal 2006, Montola 2012) and social institutions (Goffman 1974, Searle 1995), I present three ethnographic case studies that illustrate how complex forms of social gaming can conjure and sustain environments best understood as analog virtual worlds. Through the widespread use of mobile technologies and the concerted efforts of innovators, game spaces are increasingly permeating our everyday lives on- and offline. This dissolving boundary demands anthropologists to revisit questions of how, where, and with whom we play games. Dovetailing Martin Heidegger’s notions of worlding and poiesis to the semiotics of C.S. Peirce, this dissertation investigates how new forms of social gaming demonstrate the same qualities of shared intentionality, intersubjectivity, and performance essential to the production of new social meaning and cultural forms. Following, I situate the bold ethnographic case studies of make-belief in dialogue with scholars who figure exclusively online virtual worlds (Castronova 2005, Taylor 2006, Boellstorff 2008) and argue that analyzing both on- and offline virtual worlds together can help scholars better understand the fundamental nature of social interaction and shared intentionality, those everyday mechanisms that both sustain personal relationships on the one hand and maintain our broadest and most serious social institutions on the other.