Impulsivity and emotional dysregulation are two core features of borderline personality disorder (BPD), and the neural mechanisms recruited during mixed-strategy interactions overlap with frontolimbic networks that have been implicated in BPD. We investigated strategic choice patterns during the classic two-player game, Matching Pennies, where the most efficient strategy is to choose each option randomly from trial-to-trial to avoid exploitation by one's opponent. Twenty-seven female adolescents with BPD (mean age: 16 years) and twenty-seven age-matched female controls (mean age: 16 years) participated in an experiment that explored the relationship between strategic choice behavior and impulsivity in both groups and emotional dysregulation in BPD. Relative to controls, BPD participants showed fewer reinforcement learning biases, increased coefficient of variation in reaction times (CV), and more anticipatory decisions. A subset of BPD participants characterized by high levels of impulsivity and emotional dysregulation showed increased reward rate, increased entropy in choice patterns, decreased CV, and fewer anticipatory decisions relative to participants with lower indices, and emotion dysregulation mediated the relationship between impulsivity and CV in BPD. Finally, exploratory analyses revealed that increased vigilance to outcome was associated with higher reward rates, decreased variability in SRT, and fewer anticipatory decisions. In BPD, higher levels of emotion dysregulation corresponded to increased vigilance to outcome, and mediated its relationship with choice behavior. Together, our results suggest that impulsivity and emotional dysregulation contribute to variability in mixed-strategy decision-making in BPD, the latter of which may influence choice behavior by increasing attention to outcome information during the task.