Trading cards consist of a single rule card and a plurality of character cards. The rule card is formed with a data recording area on its front surface. The data recording area of the rule card is mechanically readably recorded with rule program data determining a rule of an interactive game. Each character card is formed with a data recording area on its front surface. The data recording area of the character card is mechanically readably recorded with parameter data. An electronic game machine is loaded with a cartridge, and on the electronic game machine, the interactive game according to the rule program data read from the rule card and the parameter data read from the character card is executed on the basis of a game program of the cartridge.