Restraint or danger, actually inflicted or impending, which is sufficient in severity or apprehension to deprive a person of free choice, destroy his volition, or obtain consent only in form.

Under the law, a person is not guilty of a crime if he participated only because he believed, and had good reason to believe, that he would be seriously harmed if he did not participate and had no other way of escaping serious harm. The burden is on the government to prove the defendant's guilt beyond a reasonable doubt. To find someone guilty, therefore, there must be proof beyond a reasonable doubt that when he participated in the offense, he did not have a reasonable belief that such participation was the only way he could save himself from serious harm.

An actual or a threatened violence or restraint of a man's person, contrary to law, to compel him to enter into a contract, or to discharge one.

Some divide duress into two sorts:

First. Duress of imprisonment, where a man actually loses his liberty. If a man is illegally deprived of his liberty until he signs and seals a bond or the like, he may allege this duress, and avoid the bond. But, if a man is legally imprisoned, and either to procure his discharge, or on any other fair account, seal a bond or a deed, this is not by duress of imprisonment, and he is not at liberty to avoid it.

Second. Duress per minas, which is either for fear of loss of life, or else for fear of mayhem, or loss of limb,; and this must be upon a sufficient reason. In this case, a man way avoid his own act. Lord Coke enumerates four instances in which a man may avoid his own act by reason of menaces: 1. For fear of loss of life; 2. Of member; 3. Of mayhem; 4. Of imprisonment.

Duress and Violence

It is not every degree of violence or any kind of threats, that will invalidate a contract; they must be such as would naturally operate on a person of ordinary firmness, and inspire a just fear of great injury to person, reputation or fortune. The age, sex, state of health; temper and disposition of the party, and other circumstances calculated to give greater or less effect to the violence or threats, must be taken into consideration.

A contract by violence or threats, is void, although the party in whose favor the contract is made, and not exercise the violence or make the threats, and although he was ignorant of them.

Violence or threats are a cause of nullity, not only where they are exercised on the contracting party, but when the wife, the husband, the descendants or ascendants of the party are the object of them.

If the violence used to be only a legal constraint or the threats only of doing that which the party using them had a right to do, they shall not invalidate the contract. A just and legal imprisonment, or threats of any measure authorized by law, and the circumstances of the case, are of this description.

But the mere forms of law to cover coercive proceedings for an unjust and illegal cause, if used or threatened in order to procure the assent to a contract, will invalidate it; an arrest without cause of action, or a demand of bail in an unreasonable sum, or threat of such proceeding, by this rule invalidate a contract made under their pressure.

All the above articles relate to cases where there may be some other motive besides the violence or threats for making the contract. When, however, there is no other cause for making the contract, any threats, even of a slight injury, will invalidate it.