Multi-party access control is emerging to protect shared resources in collaborative environments. Existing multi-party access control models often lack essential features to address the challenges characterizing collaborative decision-making. Collaborative access decision-making requires mechanisms that optimally account for the access requirements of all parties without requiring user intervention at evaluation time. This work fills these gaps by proposing a framework for multi-party access control based on game theory. To this end, we identify the decision factors influencing access decision making in collaborative environments and propose two bargaining models -a cooperative model and a non-cooperative model- to investigate the impact of different cooperation assumptions on collaborative access decision-making. Our framework ensures fairness by considering the access requirements of all controllers equally, achieves optimality by relying on best response strategies, and guarantees termination. Our evaluation shows that different cooperation assumptions significantly impact the performance and outcome of collaborative access decision-making.