The wall of fire spell brings forth an immobile, blazing curtain of magical fire of shimmering color—violet or reddish blue. The spell creates either an opaque sheet of flame up to one 20-foot square per level of the spellcaster, or a ring with a radius of up to 10 feet + 5 feet per two levels of experience of the wizard. In either form, the wall of fire is 20 feet high.
The wall of fire must be cast so that it is vertical with respect to the caster. One side of the wall, selected by the caster, sends forth waves of heat, inflicting 2d4 points of damage upon creatures within 10 feet and 1d4 points of damage upon those within 20 feet. In addition, the wall inflicts 2d6 points of damage, plus 1 point of damage per level of the spellcaster, upon any creature passing through it. Creatures especially subject to fire may take additional damage, and undead always take twice normal damage. Note that attempting to catch a moving creature with a newly-created wall of fire is difficult; a successful saving throw enables the creature to avoid the wall, while its rate and direction of movement determine which side of the created wall it is on. The wall of fire lasts as long as the wizard concentrates on maintaining it, or one round per level of experience of the wizard, in the event he does not wish to concentrate upon it.
The material component of the spell is phosphorus.