Though prevalent in practice, team charters have only recently received scholarly attention. However, most of this work has been relatively devoid of theory, and consequently, key questions about why and under what conditions team charter quality affects team performance remain unanswered. To address these gaps, we draw on macro organizational control theory to propose that team charter quality serves as a team-level “behavior” control mechanism that builds task cohesion through a structured exercise. We then juxtapose team charter quality with an “input” team control mechanism that influences the emergence of task cohesion more organically: team conscientiousness. Given their redundant effects on task cohesion, we propose that the effects of team charter quality and team conscientiousness on team performance (through task cohesion) are substitutive such that team charter quality primarily impacts team performance for teams that are low (vs. high) on conscientiousness. We test and find support for our hypotheses in a sample of 239 undergraduate self-managing project teams. Our study contributes to the groups and teams literature in the following ways: first, relative to previous studies, we take a more theory-driven approach toward understanding team charters, and in doing so, uncover when and why team charter quality impacts team performance; second, we integrate two normally disparate perspectives on team effectiveness (team development and team selection) to offer a broader perspective on how teams are “built”; and third, we introduce team charter quality as a performance-enhancing mechanism for teams lower on conscientiousness.