With increased participation of non-state actors in global governance, the inclusion of vulnerable groups in making sustainability regulations remains a relevant challenge requiring more research. Based on an ethnographic study on creating the Nagoya Protocol on Access and Benefit-Sharing of biological resources and knowledge, we advance a new multi-dimensional view of inclusion that integrates sustained access, involvement, and influence in the intergovernmental negotiation meetings. We elaborate the concept of decisive spaces, that is, less accessible settings where diverse actors interact in a deliberative way to co-produce recommendations and solutions to an issue that highly influence the regulatory and governance decisions. We argue that the inclusion of vulnerable actors depends on their continuous access to and involvement in these decisive spaces for creating and implementing transnational regulations. Our findings advance the understanding of inclusion for addressing challenges facing transnational governance of environmental, equity, and social justice issues.