The creation of the athame is indispensable in the transition of a student to becoming a wizard. The modern process of athemization is only 1200 years old, but was the difference between wizardry remaining one of the minor schools of magic and being the defining force in the World that it is today. It is the wizard's most used magical tool, verification that an individual is actually a wizard, and a potent magical item in its own right. Many athames have silver blades, and silver is known to be the preferred material. This may be simply tradition, though many master wizards believe it makes the athamization process easier. However, not all apprentices can afford a silver dagger, particularly if they are far away from a major city. The spell to create a wizard's athame can only be completed once in an individual's life, whether it succeeds or not; it binds a portion of the individual's soul into the knife permanently.
Athames have been described as being essentially pure wizardry, ruining many sorcerous talismans with a touch while not harming the athame. Similarly, warlocks are unable to effect athames directly with their magic. The intrinsic wizardry inherent in the athame is underscored by a number of its abilities. When brought into close proximity, two athames will react, creating a shower of sparks and a bang; this provides a useful means of identifying fellow wizards. Touching athame tips can also reveal information regarding wizardry of the owners of the athames, the brightness and vigor of sparks produced being relative to the power of the wizards. After the Night of Madness the athames of wizards who had been turned into warlocks appeared to have been depleted. Some wizards use their athames to evaluate potential apprentices, though it is unknown if that is a variation on the athame touching effect or a spell, and bringing an athame close to an active spell can cause the dagger to glow. An athame also defends its owner, cuts any rope or chain with which he or she is tied, and can ward off many Geases and minor spells. These properties cease to function with the death of the owner.
The splitting of a wizard's soul necessary to crafting an athame causes many gods to not recognize wizards as human, and prevents them from learning most other types of magic. Those types of magic a wizard can be initiated into almost universally weaken their ability to use wizardry. This effect is the source of the Guild prohibition on learning multiple types of magic; wizards are unable to do so, thus they do not want other magicians gaining an advantage over them by doing so.
One of the harshest punishments the Guild can levy against a member is the destruction of their athame, and many wizards would rather die than suffer this.