duress and self-defense

[tsukikage]

Duress exists when the wrongful threat of one person induces another person to perform an act that he or she would not otherwise have performed . In such a situation, duress is said to negate the mental state necessary to commit a crime because the defendant was forced or compelled to commit the act. Duress can be used as a defense to most crimes except murder.

By that description of duress, wouldn't killing in self defense be considered duress? And if so, wouldn't that mean that self-defense doesn't justify said killing? Or perhaps murder has a more specific legal definition that doesn't encompass killing in self-defense?

ETA: Nevermind, the next section explained the separate defense of self-defense.