Divine Magic, the Power of Faith
Divine magic is divided between two forms: the focused magic used by clerics, paladins, and rangers; and the ambient magic of Mysticism. Typically, though, the term "divine magic" refers to the power wielded by clerics.
Divine magic comes from a mortal's faith to a single deity. In return for the faith and service of clerics, they are in turn granted divine power that comes from the gods themselves. This magic can magically cure wounds, rebuke or command undead, and so on.
There are two eras in history where divine magic was not available to mortals. The first was the Time of Darkness following the Cataclysm. It was during the War of the Lance that Goldmoon rediscovered the power of the gods, and brought divine magic back to the world.
Divine magic would leave again following the Chaos War, when Takhisis stole the world. Many clerics would later learn to draw upon the power of Mysticism. Following the War of Souls, when the gods came back to the world, divine magic returned.
- Dragonlance Campaign Setting, p. 95 - 99