The development of the insurance industry in Australia in the twentieth century was fundamentally shaped by a collusive code of conduct called the tariff. This arrangement, established to overcome problems of uncertainty, initially benefited both tariff and non-tariff firms by enhancing market stability. It also reduced competition. The collusive agreements gradually broke down, however, as new entrants and products entered the market in the 1950s. Self-regulation gradually gave way as the 'rules of the game' changed. The result was a period of instability before new competitive practices, and more direct and specific regulatory requirements emerged in the 1970s.