Massively multiplayer online role-playing games like World of Warcraft are ideally suited to encourage and facilitate second language development (SLD) in the extramural setting, but to what extent do the language learners' actual trajectories of gameplay contribute to SLD? With the current propensity to focus research in digital game-based language learning on vernacular games, or commercially available games that are designed with entertainment in mind, it is vital to focus on the extramural setting in which these games are designed to be played, while still being subject to rigorous and empirical analysis. This article examines the extramural gameplay and language-learning trajectories of four university German-language learners as they play World of Warcraft with native German speakers. Positioning learners' experiences within a complex adaptive systems framework (Larsen-Freeman & Cameron, 2008; de Bot & Larsen-Freeman, 2011), the change that each learner undergoes while playing the game over the course of four months is explored in detail. Understanding the game environment as an affinity space (Gee, 2005) helps to substantiate how a game, independent of instructor guidance or classroom intervention, can still promote SLD amongst language learners of varying experiences and proficiencies. The results of this study suggest that numerous factors influence the success of a language learner's extramural gameplay experience, but that these factors must be analyzed in conjunction with the emergent internal and external resources of the complex adaptive system as language learners play and interact with other players in a context removed from the traditional classroom.