Necessity and duress (compulsion) are different defenses in a criminal case. The defense of duress applies when another person threatens imminent harm if defendant did not act to commit the crime. The defense of necessity applies when defendant is forced by natural circumstances to choose between two evils, and the criminal act is the lesser evil.
Saudi law regards contracts entered into without willing consent to be invalid, regarding both coercion and economic duress as causes for invalidity.
Jewish law does not accept duress a defense for the crime of murder, as the Talmud states (on Pesachim 25b, Yoma 82b, and Sanhedrin 74a): <blockquote>Someone came before Rava and said, "The governor of the city ordered me to slay a certain man, and threatened to kill me if I did not". Rava said to him, "Rather than slay another person, you must permit yourself to be slain, for how do you know that your blood is redder than his; perhaps his blood is redder than yours?"</blockquote>