Polycentric governance systems involve multiple decision-making forums where policy actors frequently interact. While previous research indicates that forums where actors invest more time and resources are perceived as more effective, this study, using behavioral game theory and the Ecology of Games, suggests a trade-off. Analyzing survey data from water governance systems in Tampa Bay and the California Delta, the study finds that increased participation in one forum improves its perceived effectiveness but can negatively affect the perceived effectiveness of linked forums due to behavioral spillovers.