noun
family code; house rules
Refers to the traditional rules, precepts, or code of conduct established within a family or household, often passed down through generations.
この家には代々伝わる家法がある。
This family has a family code that has been passed down for generations.
家法に従って、長男が家を継いだ。
In accordance with the family code, the eldest son succeeded the household.
Compound of 家 (house, family) and 法 (law, rule). The exact historical derivation is uncertain, but the term has been used since pre-modern times to denote the internal regulations of a family or clan.