Master Rune

This spell enables the priest to control the effects of a glyph, symbol, or magical rune written by someone else.

The most common use of a master rune spell is as follows: The priest casts the spell, then touches the location of a known or suspected magical symbol or inscription. He or she instantly becomes aware of the effects of any such magic present. The master rune spell prevents the glyph or symbol from discharging – even if the touch of the priest was its specific trigger. The priest can reduce the amount or extent of its damage or effects, but cannot increase the effect, or change its nature. The priest can also alter the conditions under which the symbol will discharge, in effect turning the symbol to obey his or her intentions rather than those of its creator.

A less common use of the master rune spell is to cast it as a protection. Thereafter, when any symbol, rune, or glyph within the spell's range is activated, the caster becomes instantly aware of its effects and can divert them, even if the inscription's presence or location was previously unknown.

Magical effects that change the state of creatures (such as petrification and polymorph magic, and enchantments causing an affliction) can be diverted to strike a nonliving target; for example, a wall, shield, or door. Magical attacks that directly harm (such as magic missiles, lightning bolts, and fire magic) must be diverted to a living target; for example, a hostile creature, or one better able to withstand the effect. The wielder of the master rune can reduce the effect of damage-causing dweomers to one-half normal (save for one-quarter). The diversion must occur within four rounds of the casting of the master rune, or it is lost. A master rune spell works only against the first symbol encountered; this expends its power.

A Deneirrath priest's alignment precludes the diversion of glyph, rune, or symbol magic to an unwilling or unwitting creature that is not in some way threatening the caster. Magics diverted in contravention of alignment, or that cannot be properly diverted, are entirely channeled into the master rune wielder for their normal effect.