Serten’s Spell Immunity

By use of this spell the magic-user is able to confer virtual immunity to certain spells and magical attack forms upon those he or she touches and magicks. 

For every 4 levels of experience of the magic-user, 1 creature can be protected by the Serten's Spell Immunity spell, but the duration of the protection is similarly disbursed upon these additional figures. (Example: A 16th level magic-user can cast the dweomer upon 1 creature and it will last 16 turns, or he or she can place it upon 2 creatures for an 8 turn duration, or upon 4 creatures for but 4 turns duration.) 

The protection gives a bonus to saving throws as follows:

Although it should be rather obvious, the spell works against nearly any form of Enchantment/Charm. Any other such spells can be adjudicated from the list in the PLAYERS HANDBOOK and herein.

The material component of this spell is a diamond which must be crushed and sprinkled over the spell recipients, and each such creature must also have in its possession a diamond of any size, intact and carried on its person.