Mage sigil

Mage sigils,  also called signature runes,  personal runes,  mage-runes,  mages' sigils,  or arcane marks were sigils designed by wizards to mark their possessions, sign their names on messages, or otherwise associate something with themselves. They were often&mdash;though not always&mdash;triggers for magical spells. Over time, common folk, being illiterate, would come to recognize the symbol of the most famous mages.

A wizard's rune played a role in many magical spells. For example, the sigil was used in the casting of any symbol spells and in many other spells that required a writing component, such as explosive runes, sepia snake sigil, fire trap, or glyphs of warding. A wizard could create a magical version of the personal sigil with the arcane mark spell.

Once created, wizards were not supposed to alter their personal rune, though some long-living mages might go through several.

No two mage sigils were identical, and using another mage's sigil was generally frowned upon and likely to result in punishment from a more powerful wizard. More importantly, the goddess Mystra herself was said to place a curse &mdash;administered by Azuth &mdash;on any person intentionally misusing a wizard's sigil for personal gain. This three-fold curse could result in weakening, loss of intelligence,  or the appearance of a glowing apparition of Azuth boldly exclaiming that the writing of the symbol was "falsely done!" This apparation could sometimes remain for days, pointing out the offender. Alternatively, some reported the loss of the abilitiy to cast the usual number of spells in a given day, a punishment that last for one month. Modern scholars rejected the idea of the Curse of Mystra as a silly folktale, insisting that such bogus claims were only made by wizards to scare others.