Contemporary Norms create the entitlements of customary landowners that are the justification for claims to share benefits in project developments governed by the Government of PNG. However, the complexity of Customary Norms and its impact on successful benefit sharing arrangements is not well understood, particularly how reciprocity and the three systems of customary land tenure and inheritance practiced in PNG, patrilineal, matrilineal, and cognatic systems, impact benefit sharing. Overall, this study proposes that the customary systems of benefit sharing, and reciprocity should be better reflected in contemporary benefit sharing arrangements. It is necessary to make the two normative systems more compatible with the circumstances of societies and communities within each resource project area and nationally.