This article investigates beliefs concerning the legitimacy of the traditional customary practice of payback in the New Guinea Islands; a practice that has been illegal for more than a century. The practice of payback is described and contextualized and a conceptual framework of norm internalization in a legal transplant society is developed. The empirical results highlight a stark urban–rural divide in attitudes. Yet, against expectations, those in urban environments (and in closer proximity to the state criminal law) are more likely to agree with the use of payback. An expected relationship is found between the ability to speak English and not agreeing with the use of payback. The empirical results suggest that the criminal law may be a weak force and that non-legal channels may be more effective in transforming society.