The Jianghu (江湖) (Cantonese: Kong Woo), which means “rivers and lakes” literally, refers to the world of martial arts.
The jianghu is an alternate universe. It consists of several martial artists gathered in the wulin (武林), usually congregated in sects, clans, disciplines and various schools of martial arts. It is also inhabited by others such as youxia (wandering heroes), nobles, thieves, beggars, priests, healers, merchants and craftsmen. The best wuxia writers draw a vivid picture of the intricate themes of honour, loyalty, love and hatred between the individuals and communities within this milieu.
A common aspect of the jianghu is the tacit suggestion that the courts of law are dysfunctional. All disputes and differences can only be resolved by use of force, as such, predicating the need for the code of xia and acts of chivalry. Law and order within the jianghu is maintained by the various orthodox and righteous sects and heroes. Sometimes, these sects may gather to form an alliance against all evils within the jianghu.
A leader, called the “wulin mengzhu” (武林盟主), is elected from amongst them to lead the sects to ensure law and order within the jianghu. The leader is usually someone with a great reputation for righteousness and a high level of mastery in martial arts, even though he is often involved in some conspiracy or killed. In some cases, the leader may not be among the greatest martial artists in the jianghu. The protagonist of the story may also become the leader by coincidence, while in some other cases such as in the television miniseries Paradise, the position of the leader is hereditary. The leader is an arbiter who presides and adjudicates over all inequities and disputes. The leader is a de jure chief justice of the affairs of the jianghu.
The term jianghu is linked to cultures other than those pertaining to martial arts in wuxia stories. It is also applied to societies where there is no law and order. For instance, the Chinese triads, secret societies and gangs use the term jianghu to describe their world of organized crime. Sometimes, the term jianghu may be replaced by the term “underworld”, with reference to the “criminal underworld”.
In modern day terminology, jianghu may mean any circle of interest such as show business, sports, etc. Colloquially, retirement is also referred to as “leaving the jianghu” (退出江湖). In wuxia stories, when a reputable fighter decides to retire from the Jianghu, he will do so in a ceremony known as “washing hands in the golden basin” (金盆洗手). He washes his hands in the golden basin filled with water, signifying that he will no longer be involved in the affairs of the jianghu. When a reclusive fighter who had apparently retired from the jianghu reappears, his reappearance is described as “re-entering the jianghu” (重出江湖). Source; wiki
Also some metaphysical and supernatural events can occur in Martial art worlds. Many high level and master martial artists have some super natural powers. In this side, Wuxia stories may be similar with modern comics where super heros exist. But there is a clear differences between them; in the Wuxia world, heros don’t get the power (either natural or super natural skills and abilities) by being mutated coincidently or inherited family wealth. They learn the technics by a master or self teaching, then after lots of paractice, they can get some super natural powers thanks to their hardworking.