The present study investigates if and how a US-Mexico border role-immersion simulation creates conditions for authenticity in an intermediate Spanish classroom. Aiming to promote whole-person engagement within a rich contextualized scenario, 16 undergraduate students adopted the roles of real-world cultural identities and were tasked with achieving individual and collective goals aimed at curbing the problems of drug trafficking and violence at the border. Learners participated in a variety of activities including becoming familiar with the scenario, selecting and developing character roles, and engaging in a set of learner-managed class sessions in which they collectively devised solutions to problems. In order to understand how the dynamic interplay among the various elements in the simulation influenced learners’ subjective perceptions, I adopted an ecological vision of the classroom and used a qualitative approach, collecting self-reported and interactional data. Following Charmaz’s (2006) Constructivist Grounded Theory, I conducted a line-by-line coding of the pre- and post-simulation questionnaires and two post-simulation interviews and then derived categories based on recurrent themes. As for the interactional data, I video-recorded and transcribed two learner-managed classes. After translating these verbal exchanges as well as learners’ virtual communications on the technology platform Google Plus into English, I coded the data in terms of agency, as operationalized by van Lier (2008), and analyzed it, drawing on complexity theory. Findings showed that a majority of learners likened their simulation experience to being immersed in real-world circumstances. These learners also exhibited high degrees of both intellectual and affective (i.e., personal) engagement during the simulation. Learners who only displayed one of the two were less likely to consider their classroom experience authentic. These results suggested that adopting an ecological perspective to explore relationships among the many dynamic elements present in the simulation uncovered the potential of this role-immersion simulation to cultivate in learners a sense that they were engaged in authentic linguistic and cultural encounters. However, data also indicated that learners’ capacity to perceive their experience as authentic and personally meaningful may be contingent on the particular nature of their encounters and their incoming views and experiences related to the communities under study.