Abstract: The Guild System implemented some regulations on working life to provide security and stability to its members. Solidarity among guild members was prioritized. While protecting its members against external risks, the Guild also provided assurance against the risks caused by the internal competition within the system. Guilds insured their members especially against unemployment and loss of earnings problems. At this point, it can be seen that the Orta Fund system has a central importance in realizing these aims. This study analyzes the interaction between the guild and the tradesmen using game theoretical models and evaluates the impact of the basic functions of the Orta Fund on Ottoman working life. For this purpose, a repeated game-theoretic model and a public good provision model are constructed. In addition, the institutional economic efficiency level of the Ottoman Guild system is evaluated in terms of economic efficiency criteria. The findings indicate that tradesmen had a high willingness to establish an Orta Fund with the incentive to develop together. For the Orta Fund system, tradesmen were willing to bear a common cost, which increased the externality effect. Thus, the sustainability of social life could be ensured. The fact that the Guild System functioned effectively for a long time in the Ottoman Empire is the most important indicator that the tradesmen were successful in this regard.