With the development of jurisprudence, the institute of legal defenses gained strong positions in criminal law theory. The idea that a person should not be punished for realizing and protecting her rights or the rights of others is generally recognized and supported. However, because the theory of criminal law differs in different countries, so differs and the implementation of this institute.
The theory on the corpus delicti in China was borrowed from the Soviet Union when the new Peoples Republic of China was born. Therefore, it is related to Russian criminal law and studies on the components of crime, which determines many similar features in both legal systems. However, China borrowed theories of the Soviet Period without paying much attention to Russian pre-revolutionary studies. Furthermore, since the 1970s, both jurisdictions have been developing separately without much influence on each other.
One of the significant differences between Russian and China's criminal law is that in China's Law, unlike in Russian one, justification and excuse may have both statutory and non-statutory bases. In the Chinese criminal law, circumstances excluding criminality of act are stipulated in the same chapter with other circumstances excluding criminal liability. Article 16 of the Criminal Law of the People's Republic of China states that "although an act objectively creates harmful consequences, if it does not result from intent or negligence but rather stems from irresistible or unforeseeable causes, it is not a crime." The Law explicitly provides the following bases for defense: "legitimate defense that is undertaken to stop present unlawful infringement of the state's and public interest or the rights of the person, property or other rights of the actor or other people"; danger prevention; mental illness, coercion into participation in crime, ignorance or mistake. There also exist other circumstances for a lighter, mitigated, or exempted punishment. However, not all of them can be classified as justifications or excuses since some refer to circumstances that arise after the crime is committed and therefore do not influence the assessment of the criminality of the action itself. There also exist recognized non-statutory bases for defending such acts that are allowed by customs. For example, despite the general prohibition of carrying weapons, minority people are permitted to wear knives or swords as part of their traditional costumes.
The defense in Chinese law applies to the legal system in general, i.e., its scope includes criminal law and administrative law, civil law, and other sectors of legislation. Therefore, if criminal law justifies an act, it cannot be punished by administrative or civil laws. For example, article 181 of the new Civil Code states that "[a] person who causes harm to the tortfeasor out of a justifiable defense bears no civil liability." However, this article also states that in case of exceeding "the necessary limit" of "justifiable defense," a person "shall bear appropriate civil liability." The general rule is that a person who caused harm in the process of legitimate defense is not subject to criminal liability. However, defense is not an absolute justification. Therefore, "responsibility shall be borne where legitimate defense noticeably exceeds the necessary limits and causes great harm." Article 21 of the Criminal Law of the People's Republic of China provides that a person should not be liable for her actions to prevent danger in a state of emergency.
Besides circumstances excluding criminality of an act, Chinese law recognizes circumstances mitigating or obstructing punishment. The general rule is stated in article 63 of Criminal Law, which acknowledges a possibility of mitigated punishment in cases stipulated in the Law or even without such stipulations. The last needs the approval of the Supreme People's Court. The example of defense not explicitly provided by the law is "exercising a legal right." This justification is mainly used in defense from article 246 of Criminal Law, which provides legal responsibility for insult and libel. However, since citizens of PRC possess constitutional rights of "freedom to engage in scientific research, literary and artistic creation and other cultural pursuits” and "to criticize and make suggestions regarding any state organ or functionary," people who cause harm to other's reputation in the result of exercising the mentioned rights may be acquitted. The law tries to find a balance between freedom of expression and protection of personal dignity.