I don't know if anything like this exists in some sourcebook somewhere, but it seems to be a natural extension of the competition between mages. Tell me if you like it, if it needs work, or if it stinks like donkey poo.
Spell Lock
Abjuration
Level: Sor/Wiz 5
Components: V,S,M, XP
Casting Time: 1 minute
Range: Short (25’+5’/2 levels)
Effect: One spell already in effect
Duration: Special
Saving Throw: None
Spell Resistance: No
Spell Lock is the Wizard’s answer to Dispel Magic. By using Spell Lock, a Wizard can “seal” the magic of an existing spell and protect it from being dispelled. The spell can only be cast on an existing spell that is already in effect. The spell to be locked must have a duration greater than 1 minute, as it must be in effect both at the beginning and end of the casting time of Spell Lock.
Once cast, Spell Lock intercepts any dispelling magic that might otherwise dispel the spell that was locked. Instead, the dispelling magic targets the Spell Lock. Spell Lock has an effective caster level equal to the caster’s level +5, for the purposes of the Dispel check only. Even if Spell Lock is dispelled, the spell that was originally locked remains in effect.
Spell Lock’s duration lasts as long as the spell that it protects. When the locked spell expires, Spell Lock automatically ends.
Material Component: Platinum dust worth 100 gp for every hour, or portion thereof, of the maximum duration of the spell to be locked, or 5000 gp, whichever is less.
XP Cost: If the spell to be locked is permanent, the caster of Spell Lock must expend 100 xp per level of the spell that will be locked.
Spell Lock
Abjuration
Level: Sor/Wiz 5
Components: V,S,M, XP
Casting Time: 1 minute
Range: Short (25’+5’/2 levels)
Effect: One spell already in effect
Duration: Special
Saving Throw: None
Spell Resistance: No
Spell Lock is the Wizard’s answer to Dispel Magic. By using Spell Lock, a Wizard can “seal” the magic of an existing spell and protect it from being dispelled. The spell can only be cast on an existing spell that is already in effect. The spell to be locked must have a duration greater than 1 minute, as it must be in effect both at the beginning and end of the casting time of Spell Lock.
Once cast, Spell Lock intercepts any dispelling magic that might otherwise dispel the spell that was locked. Instead, the dispelling magic targets the Spell Lock. Spell Lock has an effective caster level equal to the caster’s level +5, for the purposes of the Dispel check only. Even if Spell Lock is dispelled, the spell that was originally locked remains in effect.
Spell Lock’s duration lasts as long as the spell that it protects. When the locked spell expires, Spell Lock automatically ends.
Material Component: Platinum dust worth 100 gp for every hour, or portion thereof, of the maximum duration of the spell to be locked, or 5000 gp, whichever is less.
XP Cost: If the spell to be locked is permanent, the caster of Spell Lock must expend 100 xp per level of the spell that will be locked.