From the ancient times to Three Kingdoms Period, universal conscription was in place. In time of peace, people went on with their lives mostly as farmers and were summoned only for an emergency, similar to the militia system of Swiss.
During Goryeo Dynasty, foreign enemies frequently invaded the country, and in order to cope with such military situations at that time, a dual system of professional regular army and mandatory reserve forces was adopted. Therefore, a minimal regular military force was maintained by each province, enabling people to carry on with their lives, and people were mobilized only during an emergency.
At that time, people were enlisted in the military registry regardless of sex and age, and all the men between 16 and 60 years of age were conscribed if necessary. During Joseon Dynasty, the system was changed to a universal conscription of men of age between 16 and 60 years old, even in a time of peace. At times, the military service requirement was waived in exchange for paying the government with fabrics, and this system was changed due to the heavy burden on the people by reducing the amount of fabrics up to half and replacing the shortfall with tax on fishery, salt and ship.
After the Japanese Invasion of Korea in 1592, the military service requirement was expanded to include private servants for whom the requirement had been waived until then. During Late Joseon Period, the concept of universal conscription was diluted by exempting aristocratic class from military service requirements.
Even more, the government brought on a public criticism by registering the deceased and infants in the military service in order to levy more tax on the people, which became one of the reasons for the fall of the Dynasty.
The political reform of 1894 was an attempt to reform such conscription system in a modern way. Towards the end of the Dynasty, a patriotic martyr named Hong Beom-shik offered his vision of reforming the conscription system as a part of reforming the state affairs. In July 1907, the Recruiting Law was promulgated and came info force, and in August of the following year, the Military Enlisting Rules were established.
These rules were a framework for the modern conscription system detailing age, roles, time limit of the service, and recruiting plan in time of peace and war, but became a dead law by the Japanese Annexation of Korea in 1910.