The modern, simplified character is 法. Its traditional form, 灋, tells a richer story.
The simplified character 法 combines the water radical (氵) with “to remove” (去). A simple way to remember it is: the law is like water (氵), which fairly and impartially removes (去) wrongdoing.
The concept of 法 is central to one of China's most influential and controversial philosophies: Legalism (法家, fǎjiā). Flourishing during the Warring States period (475-221 BC), Legalism argued that a strong state depends not on the moral virtue of its ruler (as Confucians believed), but on a strict, publicly known, and impartially enforced system of laws. This philosophy was famously implemented by the state of Qin, enabling it to unify China and establish the first empire.
Beyond politics, 法 also entered China with Buddhism, where it's used to translate “Dharma” (佛法, fófǎ), meaning the cosmic law and order, or the teachings of the Buddha.
法 is an incredibly versatile character used in many contexts.