Digital games have become a social medium. Players are often socially motivated to play games and actively seek out games that offer social interactions. Early studies on games such as World of Warcraft demonstrate that players can form meaningful bonds within the game. Catering to this trend, most game titles now include multiplayer experiences in their gameplay. Despite the growing popularity of social elements within play, we still have little empirically-founded guidance on how to effectively design for social experiences. If we want to design for social play, we have to understand what makes games social. What are the properties of play that are responsible for facilitating social ties between players? We address this question by synthesizing the exiting literature on design recommendations for social play into identify overarching properties of play that we think are the most prolific in literature: cooperation and interdependence. We perform two experimental studies demonstrating how games facilitate trust between players and how cooperation and interdependence are crucial properties of social play. Furthermore, we validate our framework in a field study, investigating the experiences within games that predict in-game social capital. We demonstrate that interdependence and toxicity are strongly linked to the social capital our participants experience in their gaming communities. We also illustrate how in-game social capital is negatively associated with feelings of loneliness and positively associated with need satisfaction of relatedness outside of the context of play. Overall, our findings emphasize how strongly the experiences within the game affect the social ties that emerge from play, suggesting that informed design choices are crucial for the success of social games. This dissertation also contributes to the ongoing debate about the effects that in-game relationships have on the player’s mental health—we show a strong positive link between in-game social capital and markers for psychological well-being. It is easy to disregard in-game relationships, as they are fundamentally distinct from the in-person ones we think of as natural. Yet we cannot ignore the emergence of digital games as a social medium. The more we understand the underlying elements of social play, the better we can design games that bring people closer together
