A unique feature of clerical magic is faith magic. Using this special category of priest spells, clerics can create semipermanent wards, sanctify ground, ensure good harvests, or even improve the health of followers. In short, this amplified magic allows certain clerical spells to be increased and intensified through the combined efforts of priests and worshipers. Range, area of effect, duration, and even damage can be altered through devotion and combined spellcasting.
To gain this ability, priests and their worshipers form groups to create faith magic. Clerics of nearly all religions seek out worshipers, establish temples, retire to monasteries, and establish seminaries. While there are many mundane reasons to form such groups, priests' attitudes are also shaped by this important difference between clerical and wizardly magic—the ability to combine magical power. Wizard spells lack this property—even a large number of wizards cannot combine their spells into a whole. Thus, wizards gain no magical benefits from founding monasteries or attracting followers.
The core of faith magic is devotional power. This power comes from the dedication of ardent followers and priests. It is not something that can be manipulated directly (like a spell), although it is the source of power for spells. Unlike magical energy, devotional energy is not tied to a particular character class. Ordinary people are as much a source of this power as are adventurers. Only priests are significantly different, their lifelong dedication to their god being the wellspring for even greater power.
Not everyone is a source of devotional energy. Almost every character generates a small amount of power, but only those persons dedicated in their beliefs provide the amounts needed for faith magic. Even at this level, the total energy provided by each person is very small. Thus, faith magic can be used only when large numbers of sincere worshipers gather, such as particularly devout congregations, monasteries, seminaries, and universities operated by a religious order. Sincere belief is the most important factor. While persons attending a service may be numerous, casual followers do not contribute to the effect.
Before its power can be harnessed, the devotional energy of a group must be gathered and concentrated toward a single effect. This is known as focusing the effect. Once focused, the devotional energy provides power needed to maintain a spell effect, increase its area of effect, or create a number of other different results. A focus is created by means of the spell focus.
Once the devotional energy has been focused, the cleric or clerics can cast the spell to be amplified. Using the devotional energy gathered by the focus, the spell's effect is increased in area of effect and duration. The exact increase depends on the level of the priest who casts the focus. Such amplified spells typically affect a building (such as a church or hospital), group of buildings, or even an estate.
The spell remains in effect as long as the focus exists. This requires a minimum number of worshipers and periodic renewals of the spell. Since the duration of a focus is long, these renewals often coincide with important festivals of the religion, when numerous worshipers are present to provide devotional energy.