In the presence of certain circumstances, the actions of the subject, as a result of which the harm is caused, will not be regarded as a crime. Exemption from liability occurs if necessary defense and extreme necessity have taken place. Criminal law contains special rules governing such cases. Let's consider them in more detail. 
Clarification of concepts
What is necessary defense and emergency? Article 37 provides for the release of the subject from liability for damage caused to the attacker, if the attack was accompanied by violence that poses a threat to the life of the defending or other citizen or with an immediate threat of its use. Thus, the actions of a person are recognized as legitimate. Necessary defense and urgent need The Criminal Code of the Russian Federation is considered as specific circumstances in which the subject is located. Art. 39 provides for the release from liability of the person who caused harm in the process of eliminating the danger that directly threatened the defended or other citizens, state or public interests, if it could not be eliminated by other means. Moreover, the norm stipulates that the subject in his actions should not exceed the limits of emergency. Thus, harm is considered to be lawful if a person is in such a position that he is forced to do less damage to other rights to eliminate the danger to one interests. 
Essential Defense and Extreme Necessity: Similarities and Differences
The subject can be in different conditions under which the harm caused to him can be regarded as legitimate. The necessary defense and the state of emergency have differences and a number of common features. The main one of the latter is the fact that the legislation officially allows any harm to one’s interests or citizen to preserve the life, rights or health of another entity. Along with this, the norms indicate specific conditions under which the necessary defense and extreme necessity take place. Practical examples show that even murder will not act as a crime if the established conditions for the lawfulness of the defense are met. Thus, the deprivation of life of an alarmist on a sinking ship can prevent panic among other citizens, keep their minds, which can later help them escape. Necessary defense and extreme necessity require a choice between lesser and greater evil. This thesis contains the moral aspect of the problem. In society, sacrifice is perceived quite normally by a lesser good for the salvation of more. The legislation only fixed this axiom officially.
Right and duty
Necessary defense and extreme necessity appear as states that in the general case do not oblige the subject to anything. Every citizen has the opportunity to use his right. However, the legislation does not establish any liability for refusing it. Meanwhile, there are a number of exceptions. Certain categories of persons are required to exercise this right in appropriate cases. This, in particular, applies to employees of the fire service, military, police, employees of other units of the police department and other citizens whose professional activities are related to situations in which they must protect someone else and their interests. 
The specifics of the assault
Necessary defense and extreme need take place in specific conditions. The law stipulates that the actions of the subject can be recognized legitimate in the presence of serious encroachment or danger. In this case, it is understood that the threat must appear, exist and not end. With a complete or probable future encroachment or danger, the necessary defense and extreme necessity cannot arise. For the legitimacy of the harm, the threat must be real. It should exist not only in the representations of the defender or acting in extreme necessity, but also in objective reality.
Scope of the exercise of law
Protection, in case of emergency, and with the necessary defense must coincide with the encroachment or threat in time. The framework for the exercise of law is determined by the initial and final moment of danger. Delayed or premature protection has nothing to do with circumstances precluding the unlawfulness of the act. One of the key common features of the conditions under consideration is the concept of going beyond the bounds of extreme necessity and necessary defense. Protection will be lawful if the limits have not been exceeded. In legislation, there is a reservation. The norms say that deliberate actions that are committed in the defense process are exceeded. 
Difference between concepts
The general features possessed by the necessary defense and extreme necessity were considered above. The differences between these concepts, meanwhile, are quite substantial. One of them concerns the source of danger. With the necessary defense, they are the actions of another subject. Direct reference to this is present in the law. As for extreme necessity, here the sources of threat are not only the actions of people. It can be:
- Natural forces, elements, objective processes occurring in natural conditions (avalanches, snowfalls, hurricanes, earthquakes, floods and so on), creating a danger to property, health, life of the population.
- Animal attacks.
- Faulty mechanisms.
- Pathological, physiological processes (disease, hunger). For example, a person who has lost his way in a forest kills an animal or bird, for which hunting is prohibited in order to feed itself.
- Conflict of dangers. For example, a witness summoned to court remains with a sick relative.
Features of harm
With the necessary defense, damage is done only to the encroaching subject and exclusively to the person, and if absolutely necessary, to the person, as a rule, not associated with the danger that arose. In the latter case, harm is caused to interests protected by various regulatory enactments. With the necessary defense, the attacker for a certain time gets out of the protection of the law and returns under it only after the end of the actions of the defender. The latter will not be considered criminal if the damage they caused is less than, equal to or slightly more than prevented. The defender does not need to take care of the harm done. However, he must remember the limits of his actions. 
Necessary defense and extreme need for civil law: examples
The legislation provides for operational measures by which an impact is made on the violator. They are such legal means that are used by an authorized person acting as a party to the relationship, without contacting the competent authorities for protection. These measures include:
- Unilateral withdrawal from the contract violated by another member.
- Delay in the delivery of goods to the receiving entity until they make the necessary payments, etc.
The necessary defense and the extreme need for civil law are not actual, but legal in nature.They always entail a change in the scope of opportunities and responsibilities, primarily for the violator.
Key features
First of all, operational measures are considered law enforcement. They can be applied only if the obligated entity has committed any violation. For example, a person has not taken appropriate actions on time, regularly delays payments and so on. It should be noted that the measures provided for in legislation are always one-sided. The party whose interests are violated, there is no need to seek help from the competent authorities. This is what their name determines - operational. The unilateral nature also determines the specifics of guarantees for the correct application of measures. First of all, they can be used only when they are expressly provided for by agreement or regulation. At the same time, the application of measures does not exclude the possibility of the obligated subject to challenge their application in court. 
Classification of measures
The actions taken by the entity in relation to the offender may be different. However, in practice, the following types of measures are distinguished:
- Associated with the performance of obligations at the expense of the debtor. General rules regarding this measure are provided for in Art. 397 Civil Code. In accordance with the norm, if the debtor fails to fulfill the obligation to manufacture and provide the thing, perform some work / provide the service, the creditor may entrust the third party to fulfill it within a reasonable time for a fee or do it yourself, unless otherwise provided by the agreement, the essence of the relationship, the law or other regulatory acts. At the same time, he has the right to demand compensation from the obligated person for expenses and other losses.
- Concerning the provision of counter-satisfaction. The rules regarding the application of this measure are formulated in Art. 395. The norm stipulates that a creditor who has a thing that is subsequently to be transferred to the debtor or to the citizen indicated by him may, in case of non-fulfillment of the obligation to reimburse storage costs or to pay it, hold it until the conditions of the agreement are realized.
Additionally
There are also precautionary measures. The rules for their application are established in Art. 328 (paragraph 2) of the Civil Code. Such measures include the cancellation of the contract, the adoption of improper performance, in mutual satisfaction due to incomplete performance of the obligation. According to Art. 328, paragraph 2 of the Civil Code, in case of violation of the terms of the agreement, the second party, which is the debtor for offsetting, has the right to suspend the implementation of the contract unilaterally or to refuse it. It may also require compensation for losses incurred as a result of the improper performance of obligations by the violator. 
In this case, it should be borne in mind that in case of a unilateral refusal to implement the conditions partially or completely, if permitted by law or by agreement, the contract will be considered terminated or amended.
