Used as a ranking system to quantify skill level in a specific domain, it was originally used at a Go school during the Edo period.

Today, this ranking system is part of the hallmark, landscape, and cultural "adhesive" of modern Japanese society.

[citation needed] The Chinese character for the word dan (段) literally means step or stage in Japanese, but is also used to refer to one's rank, grade, or station, i.e., one's degree or level of expertise, knowledge and seniority.

The dan ranking system in Go was devised by Hon'inbō Dōsaku (1645–1702), a professional Go player in the Edo period.

[5] There was still no external differentiation between yūdansha (black belt ranks) and mudansha (those who had not yet attained a dan grade).

Different athletic departments within the Japanese school system were already using markers of rank, most notably in swimming, where advanced swimmers wore a black ribbon around their waists.

[citation needed] At that time, these obi were not the belts that karateka and jūdōka wear today; the students were still practicing in kimono.

This means that players will have to show good results in tournaments or pass exams to be awarded a dan rank.

In addition to dan and kyū, an Elo-type rating system is also used by the Japan Amateur Shogi Association for the tournaments it organizes.

The ranking system used by the Japan Shogi Association (JSA) for professionals uses similar terminology, but is actually quite different in terms of ability.

Shōreikai 3-dan players who either win or finish runner-up in one of the two 3-dan league tournaments held each year are awarded the rank of 4-dan and granted professional status.

In modern times, a dan-ranked practitioner of a style is usually recognized as a martial artist who has surpassed the kyū, or basic, ranks.

The higher dan grades usually require years of experience and contribution to the relevant modern martial art.

In martial arts such as iaidō, kendō or jōdō, no external signifier of rank is worn, though a black belt is by far the most recognizable symbol to the general public.

In other styles, the dan ranks are not the highest level that might be attained, with instructor certification and judge/judgment authorization being understood as higher-level or more sophisticated.

Blue with a red stripe is sometimes worn for Renshi (錬士) or for a person recognized by the older Ryu Kyu Kingdom title of Shinshi (from Shenshi, 紳士), a general Confucian term for a resident Chinese scholar and emissary.

[12] In the early 2000s, different Okinawan styles started using the stripes to designate individual dan grades above godan.

Generally, the lower dan grades are achieved by gaining greater knowledge and understanding of the art along with physical skill.

The higher the dan grade, the more leadership ability, teaching experience, and service to the style play a role in promotion.

The dan system and the well-known symbol of a black belt have been absorbed into common usage to represent a person with above-average or highly trained skills in a particular discipline.

Starting from 5th Duan, there has to be proof of a scientific work in wushu research, i.e. publications, DVD, training of Duanwei examined students.

In some Korean schools, most notably in Kukkiwon-style Taekwondo, there is also a poom system in place (품, 品; "pum" using standard Romanization).

Political tensions having to do with status and rank, predate the introduction of the Dan grading system by centuries.

[15] However, the introduction of the Dan ranks has led to the creation of new and specific types of 'rank politics' and social conflicts, which sometimes afflict martial arts schools and organizations.