Rules: Magic Mishaps
When casting any spell with a requirement, if the casting roll fails and the Stunt Die result is a 1, a magical mishap occurs.
When there is a magical mishap the caster immediately makes a Willpower (Self-Discipline) test against the spell’s target number. A successful test means the caster is knocked prone, with the usual consequences (that is, it takes a move action to get back up and opponents gain a +1 bonus on attack rolls). The mage may avoid the ignominy of falling over by spending additional magic points equal to the spell’s original cost. If the Willpower test fails, the outcome of the mishap is based on the Willpower test’s Stunt Die.
Dragon Die = Stunt Die * Mana = Magic Points