Compare Confucianism's emphasis on virtue and proper relationships with Legalism's emphasis on strict law as competing answers to the chaos of the Warring States period.
By the 400s BCE, Zhou royal authority had crumbled, and rival states fought constantly in what historians call the Warring States period (475-221 BCE). Out of that chaos came a burst of competing philosophies, later called the "Hundred Schools of Thought," all wrestling with the same urgent question: how do you restore order? Confucius (Kong Fuzi), who lived from 551 to 479 BCE, taught that order comes from virtue and from proper relationships -- ruler and subject, parent and child, husband and wife, older and younger sibling, friend and friend -- each carrying its own responsibilities. He emphasized education, respect for elders and ancestors, and a golden-rule-like idea: do not do to others what you would not want done to yourself. His students collected his teachings after his death into a book called the Analects.
Confucius believed people could be guided toward good behavior through moral example and proper conduct rather than through fear of punishment. A rival school, Legalism, argued the opposite: philosophers such as Han Feizi believed people are naturally self-interested, and that only strict laws with harsh, consistently enforced punishments -- backed by a powerful central ruler -- could keep a state stable. This direct disagreement, virtue versus law as the true path to order, would shape Chinese government for the rest of ancient history: the very next dynasty you will study chose Legalism first, and the dynasty after that chose a version of Confucianism instead.
Mastery looks like: They can accurately state Confucianism's and Legalism's different answers to restoring order and explain that both arose from the same Warring States crisis.
Common stumbles: Confusing which philosophy favors virtue and which favors strict law, or assuming one was obviously right and the other obviously wrong.