An enchanted knife increases the likelihood of success when casting certain other spells, as well as performing as a magical weapon (able to inflict harm on Mythos entities who would otherwise be unaffected by mundane weapons).

The spell enchants a knife or dagger made of a pure metal, such as gold or iron. The caster draws an intricate diagram, using the knife’s blade, on a flat surface, and then the blade is used to kill an animal of at least SIZ 20. The creature’s blood is then traced out to follow the lines of the diagram and the enchantment is complete.