The term sān gāng (the Three Bonds) refers to a foundational concept in classical Confucian ethics, describing three fundamental hierarchical relationships that uphold social harmony and moral order: ruler-subject, father-son, and husband-wife. Each bond prescribes mutual responsibilities — especially loyalty, respect, and righteousness — though historically it emphasized the subordinate’s duty to obey and honor the superior. The character sān means 'three', while gāng literally means 'main rope' or 'guiding principle', metaphorically signifying the central, binding moral pillars of society.

Though rooted in ancient texts like the Book of Rites, sān gāng is rarely used in modern daily speech; instead, it appears primarily in academic, historical, or philosophical discussions about traditional Chinese values, ethics education, or critiques of hierarchical thinking. Understanding this term helps learners grasp how Confucian thought shaped interpersonal expectations, family structure, and state governance for over two millennia.