Universal Spell Power

Newer effect
Universal Spell Power is a separate and stacking source of Spell Power.
 * Implement bonus to universal spell power was introduced with Update 14; it can be found on Spellcasting Implements.
 * Exceptional bonus to universal spell power was introduced with the Mists of Ravenloft expansion.

Its stacking nature makes it particularly attractive, for example Exceptional Universal Spell Power found on stacks with Exceptional Devotion found on.

Older effect
Some older items used the name Universal Spell Power for a bonus that affected all Elemental, Light, Postitive, and Negative spell powers, but did not intrinsically stack with other specified spell power bonuses of the same type (Equipment bonus, Insightful bonus, Artifact bonus, etc...). Items that possess this effect have had it's name changed to Potency in most cases.