Empowerment means to increase a commander's magic path by one by the use of gems. This can only be done in a province with a lab in it. A mage may permanently increase his skill in any path of magic by using Empowerment. For the first skill level in that magic path, the cost is 50 magic gems of that type. For subsequent increases the cost depends on the current skill in the magic path and is 15 x target level. This is the only way to gain skill in a path a unit doesn’t have. Magic items which increase magic skill only work if the user’s skill in that path is at least 1. Of interest, magic items do not increase the cost to empower in certain paths. This is also true of battlefield spells which confer a path bonus, like Power of the Spheres.