The need for new theoretical and experimental approaches to understand dynamic and heterogeneous behavior in complex economic and social systems is increasing. Computational and gaming simulations are expected to be able to reproduce complex phenomena in economics, and helps us to experiment with various controlling methods, to evaluate systematic designs, and to extract the fundamental elements which produce the interesting phenomena in depth analysis. We developed a simple agent-based simulation framework "ASIN" and its applications for economic and environmental studies including the international greenhouse gas (GHG) emissions trading. We also constructed a Web application for the gaming simulation of the emissions trading with human players to investigate and improve the behavior model for agents. We introduce a transaction procedure with state transitions in the hierarchical cycle whose design is well suited to this type of social experiment. We also utilize this management system in the Web-based gaming system.