Spheres
From Crossroads Wiki
The Breath of Imperium comes in three forms, which have been adopted as three primary spheres of magical study: Elemental, Illusion, and Transportation. Most mages specialize in one sphere, learning only enough of the other spheres to refine and expand their primary skills. Further, each sphere is comprised of sub-spheres, providing even more specialization. In general, the more a mage specializes, the more powerful he or she can become in that particular sub-sphere. The corollary to this rule is that the more a mage tries to generalize, the less effective he or she will be working any particular magic.
All rules have exceptions, and the rule of specialization is no different. Three secondary spheres have developed over time, a result of "specializing in the general combination" of two of the other spheres. Elemental and Transportation combine to form the sphere of Enchantment. Transportation and Illusion combine to form the sphere of Scrying. And, finally, Illusion and Elemental combine for the sphere of Transformation.
Combining all three spheres is necessary for the most complex, yet also the most general specialization, Summoning. It is rare that someone has both the magical capacity and training requirements to accomplish this, and the only public figure known to be able to summon is the Duke of Mists himself.
For information on the individual spheres, read the following articles:
