Two

이 (i) means “two” and belongs to the Sino-Korean number series (일, 이, 삼…). That series coexists with the native series (하나, 둘, 셋…). In Korean, Sino-Korean numerals are used for order and numbering: for example “2층” (second floor) and the jersey number “2번” are read with 이.

In kumdo the term appears mainly in 이도 (ido, 二刀), meaning “two swords”. It is the style of fighting with two 죽도 (jukdo, bamboo swords) of different sizes: the 대도 (daedo, long sword) and the 소도 (sodo, short sword). A Korean source says that in kumdo 이도 is the correct form rather than 이도류, because 류 (流) refers to a school or lineage.

• According to a Korean source citing the Japanese federation's criterion, the 정이도 (jeongido) holds the 대도 in the right hand and the 소도 in the left. The 역이도 (yeogido) is the reverse.
• The same source distinguishes 정족 (jeongjok) from 역족 (yeokjok). It is 정족 when the foot on the 대도 side steps forward and 역족 when the foot on the 소도 side does.
• The Korean Kumdo Association (대한검도회) gives equipment limits for 쌍도 (ssangdo, two swords): the 대도 up to 114 cm and the 소도 up to 62 cm.
• In the 코등이싸움 (kodeungissaum, guard-to-guard pushing), a player using 이도 must cross the 소도 under their own 대도. It is a foul if the 대도 is below and the 소도 above.

In rank rules, sources write the second dan as “2단”. It requires one year after the first dan (초단) and an age of 16 or over.

In the Korean Kumdo Association textbook, the cues for practice strikes use native numerals (「하나」, 「셋」), not 이.