Rules are fundamental to the implementation of conservation policies, but cannot change behavior if they are not known or understood. Despite this, few studies have investigated knowledge of conservation rules or factors influencing it. Here, we quantify the effects of involvement with tourism and community-based natural resource management, education and demographic factors on local people's awareness of Madagascar's species protection laws. Knowledge of the laws was generally low. However, those who worked as tourist guides, hosted tourists, and were involved in local forest management committees were almost twice as likely to classify correctly a species as protected compared with individuals not exposed to conservation messages in this way. This year marks 50 years since Madagascar introduced its first species protection law. It is time to recognize that rules are necessary, but not sufficient, for species protection and to devote more attention to the communication, and enforcement, of conservation rules.