Treacherous Weapon(Exemplars of Evil, p. 29)
Level: Bard 1, Hexblade 1, Sorcerer 1, Wizard 1, Spellthief 1,
Components: V, S,
Casting Time: 1 immediate action; see text
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature
Duration: 1 round
Saving Throw: Will negates
Spell Resistance: Yes
You make a gesture accompanied by a sharp arcane command, and your foe's weapon gives off a momentary shower of sparks.
You can cast this spell on any creature wielding a manufactured weapon. If the target fails its saving throw, the weapon takes a —1 penalty on attack rolls and damage rolls.
For every two caster levels beyond 1st, the penalty worsens by 1. Thus, at 3rd level, the weapon takes a —2 penalty; at 5th level, a —3 penalty; at 7th level, a —4 penalty; and at 9th level or higher, a maximum —5 penalty.
When this spell is cast on a creature wielding a magic weapon, subtract the weapon's enhancement bonus from the penalty. For example, a 1st-level caster would reduce a +1 longsword to a +0 longsword.
If you extend the spell's casting time to 1 standard action, the enhancement penalties double.