Dispel Magic
Dispel magic can be used to completely dispel most spells and enchantments. As an example of how one might referee this spell, the chance of dispelling magic could be a percentage based on the ratio of the level of the caster trying to dispel over the level of the caster (or HD of the monster) who hurled the original magic. Thus, a 6th level Magic-user attempting to dispel a charm cast by a 12th level Magic-user has a 50% chance of success (6 / 12 = 1/2). If the 12th level Magic-user were dispelling the 6th level Magic-user’s charm, the dispelling caster’s chance of success would be 200% (12 ∕6 = 2).