Disbelief

This spell allows the caster to temporarily convince himself that certain objects or as many as four creatures within the area of effect do not actually exist. While disbelief remains in effect, these objects or creatures cannot harm or hinder the caster. He can pass through them as if they did not exist and takes no damage from their attacks or actions. However, since these objects or creatures temporarily do not exist for the priest, he can take no action against them. If the creatures attack, the caster receives no Dexterity bonus to armor class (since this bonus represents dodging, and the priest is unable to dodge a creature that does not exist for him).
The caster can attempt to disbelieve as many as four creatures within 60 feet of his position at the time of casting. He disbelieves the same four creatures for the duration of the spell. Alternatively, the priest can disbelieve any or all inanimate objects of up to 20-cubic-yard volume (thus, he may disbelieve a 12 foot by 15 foot area of 3-foot-thick wall). This volume must be centered on a point no more than 20 yards from the caster. These two options are mutually exclusive; the priest can disbelieve only creatures or objects, not a combination of both.
Disbelieving a creature includes all gear, equipment, or treasure carried or worn by that creature; it does not include other objects that come into contact with that creature, such as walls, doors, chairs, etc.
Disbelief is not automatic; it requires an extreme effort. To successfully disbelieve, the priest must make a saving throw vs. paralyzation. A successful save means the priest has disbelieved; an unsuccessful check means that the spell has failed and the priest has not convinced himself of the creatures' or objects' non-existence.
While this spell is in effect, the DM must record any damage suffered by the priest from disbelieved creatures. When the spell ends, the caster makes a saving throw vs. spell. If the saving throw is successful, the priest suffers only one-eighth of any damage inflicted by the creatures (round all fractions down if the priest fails the saving throw, he suffers one-half of any damage inflicted (round fractions down).

[Tome of Magic]

Sphere: Thought
(Enchantment/Charm)
Level: 6

Range: 0
Components: V, S
Duration: 1 round/level
Casting Time: 5
Area of Effect: Special
Saving Throw: Special