When the spell is cast it confers complete invulnerability to all weapons except for those of +4 or better enchantment. This spell is incredibly powerful hence the duration is so short. However, the casting time is also very short making this spell incredibly useful in the thick of combat where buying a few seconds can mean the difference between life or death. It is important to note that this spell does not work in combination with Protection from Magical Weapons. This spell lasts for the duration or until dispelled.