Thief's Lament

A thief entering an area enchanted with thief's lament suffers a great reduction in his thieving skills. The thief is allowed a saving throw to resist the effects of the spell; failure indicates that he suffers the full effects of the lament. All attempts to pick pockets, open locks, find/ remove traps, move silently, detect noise, climb walls, and hide in shadows are reduced by 25% (although a skill cannot be reduced below 5%, presuming the character has at least a score of 5% in any skill).
The spell affects a cube whose sides equal the caster's level times five feet (a 10th-level caster could affect a cube whose sides equal 50 feet).

[Tome of Magic]

Sphere: Wards
(Alteration)
Level: 3

Range: 10 yards/ level
Components: V, S, M
Duration: 1 hour/level
Casting Time: 3
Area of Effect: 5-foot cube/level
Saving Throw: Negates

Material Components:
the priest's holy symbol and a silver key