The jiang hu or gong woo world is the fictional environment in which many wu xia stories are set. The term jiang hu (江湖) can be translated literally as "rivers and lakes"; metaphorically, it refers to any wild or unsettled region. In medieval China, outlaws often fled to the frontiers, returning only to prey upon the straight world.
The roots of jiang hu wu xia go back at least as far as the 12th-century novel The Water Margin (水滸傳), in which a band of noble outlaws retreat to a swampy hideout and mount wrong-righting sorties against corrupt officials.
In modern days, the term jiang hu is still frequently used to refer to the society among gangsters. A 2004 movie titled Jiang Hu starring Andy Lau, Jacky Cheung was about the gangster societies in Hong Kong.
JiangHu members recognized each other via a complex system of secret signs and signals - a newcomer visiting an inn, for example, could arrange chopsticks and teacup in a certain pattern on his tabletop if he wished to contact the local affiliates.
Stories of the JiangHu emphasize the complex web of obligations and feuds that proliferated in the shadow world and were refered to as "the love/hate relationships of the martial world".
Although the JiangHu society operated outside of the law and not only tolerated but also plotted with and protected lawbreakers, a segment of the membership took it upon themselves to offer protection from evildoers, perhaps operating on the maxim that "it takes one to know one".