In the modern world, many important tasks have become too complex for a single unaided individual to manage. Teams conduct some safety-critical tasks to improve task performance and minimize the risk of error. These teams have traditionally consisted of human operators, yet, nowadays, artificial intelligence and machine systems are incorporated into team environments to improve performance and capacity. We used a computerized task modeled after a classic arcade game to investigate the performance of human–machine and human–human teams. We manipulated the (...) group conditions between team members; sometimes, they were instructed to collaborate, compete, or work separately. We evaluated players' performance in the main task (gameplay) and, in post hoc analyses, participant behavioral patterns to inform group strategies. We compared game performance between team types (human–human vs. human–machine) and group conditions (competitive, collaborative, independent). Adapting workload capacity analysis to human–machine teams, we found performance under both team types and all group conditions suffered a performance efficiency cost. However, we observed a reduced cost in collaborative over competitive teams within human–human pairings, but this effect was diminished when playing with a machine partner. The implications of workload capacity analysis as a powerful tool for human–machine team performance measurement are discussed. (shrink)