A peasant kneels in the mud, clutching a smear of rice, while a clerk flips through a list of names. The clerk finds the suspect's family line, and the punishment shrinks.
In the eighth century Silla began to write its laws down in a serious way. King Gyeongdeok (경덕왕) pushed officials to copy Tang models and put penalties on paper. The new codes looked like fairness, but the lines they drew followed blood and marriage, not equal guilt.
The Samguk Sagi (삼국사기) keeps examples that make you wince. A commoner caught stealing might get lashes, exile, or conscript labor. A noble who stole or killed often got a fine, loss of rank, or banishment to a temple instead. The law named who could be punished harder, and that list tracked the bone-rank system (골품) more than the act itself.
Over in Balhae, the mood was different. Dae Joyeong (대조영) set up a state that Chinese histories said kept written codes and standing courts. The Old Book of Tang (舊唐書) notes judges who handled merchants and foreigners, and records of appeals. That helped settle trade fights and cross-border disputes without everything ending in swordplay.
So both polities brought paperwork to punishment, but with different goals. Silla used law to lock social order into place. Balhae used it to run a mixed society and keep markets moving. In both places the law was a political tool you could plead, bribe, or marry around if you had the right name.
Laws looked like neutral rules, but they often protected the powerful. If you think modern legal immunity is new, imagine a clerk changing your fate after he reads your family name.