Meaning "specially-selected troops", the Sambyeolcho originated from a unit called the Yabyeolcho (야별초, 夜別抄, Special Night Unit), which was established to prevent burglaries and to provide night time security in the capital.
When a number of soldiers had been taken prisoner by the Mongols and then escaped, they were organized into a third force, the Sinuigun (신의군, 神義軍), and these three came to be known collectively as the Sambyeolcho.
The Sambyeolcho performed both police and military functions but were elements of the private army of the Ch'oe family.
The Sambyeolcho together with the Dobang (도방, 都房) comprised the means by which the Ch'oe family military dictators projected their power after their military coup usurped the royal power.
The Sambyeolcho was an army with a strong public character in combat with the police, and its conductor has also been assigned a national official such as Doryeong.