This spell protected a spherical volume with a radius of 40 ft (12 m) for a duration of four minutes. The center of the effect could be set at a distance of 210 ft (64 m). More experienced casters could increase this range. During this time, all normal fires were extinguished and magical fires had one chance to resist the spell or be snuffed out. New fires could not be started inside the designated sphere for the duration of the spell. All creatures got one chance to resist the spell. Creatures with a fire-creating power had to overcome the magic of this spell each time they attempted to use their powers. Magically created fires (which included fire elementals and fireballs) were prevented or extinguished by random chance, with the odds decreasing as the level of the fire-causing effect increased. Note that fires started by fireball and similar agents were considered normal fires after the magical effect dissipated.
This spell was often cast in anticipation of a fire-based attack. The area of effect was fixed at casting time and did not move with the caster or anything else that was designated as the center of the effect.
In addition to verbal and somatic components, this spell could use a variety of material components. Items known to work were a chip of ice, a cupped handful of water, a pinch of sand, or even some of the caster's saliva.
According to Dalamar, an archmage from the world of Krynn, this spell was invented by an evil wizard known as Fistandantilus. Dalamar gave copies of this spell to Elminster and Mordenkainen, an archmage from Oerth, at one of their meetings at the house of Ed of the Greenwood.