In Chinese history, Legalism (Chinese: 法家; pinyin: Fǎjiā; Wade–Giles: Fa-chia; literally “School of law”) was one of the main philosophic currents during the Warring States Period (and before), although the term itself was invented in the Han dynasty and thus does not refer to an organized ‘school’ of thought. Legalism was a utilitarian political philosophy that did not address higher questions like the nature and purpose of life. The school’s most famous proponent and contributor Han Fei Zi (韓非子) believed that a ruler should use the following three tools to govern his subjects:
Fa (Chinese: 法; pinyin: fǎ; literally “law or principle”): The law code must be clearly written and made public. All people under the ruler were equal before the law. Laws should reward those who obey them and punish accordingly those who dare to break them. Thus it is guaranteed that actions taken are systematically predictable. In addition, the system of law ran the state, not the ruler, a statement of rule of law. If the law is successfully enforced, even a weak ruler will be strong.
Shu (Chinese: 術; pinyin: shù; literally “method, tactic or art”): Special tactics and “secrets” are to be employed by the ruler to make sure others don’t take over control of the state. Especially important is that no one can fathom the ruler’s motivations, and thus no one can know which behaviour might help them getting ahead; except for following the 法 or laws.
Shi (Chinese: 勢; pinyin: shì; literally “legitimacy, power or charisma”): It is the position of the ruler, not the ruler himself or herself, that holds the power. Therefore, analysis of the trends, the context, and the facts are essential for a real ruler.
Definition courtesy Wikipedia.