Summoning skill

Summoning is a Warrior Mage-only skill that represents a WM's facility with the elements - it affects familiar summoning, Aethereal Pathways, etc.

"Warrior mage" is not in the list (None, Bard, Barbarian, Cleric, Empath, Moon Mage, Necromancer, Paladin, Ranger, Thief, ...) of allowed values for the "Guild association is" property.