Spells are lesser magical abilities that can be taught to the average spellcasting unit or agent, all spells have certain characteristics such as Range, Damage, Mana cost and Requirements. Spells must be researched and then they are added to a nation's spell library, from where they can be equiped on a spellcasting unit. Spells consume the units magical power in battle so they can be cast only a limited amount of times.
Powers are greater magical abilities that can be taught only to extraordinary people known as Heroes. Once a power has been researched, it can be learned by any Spellcasting Hero under the nation's control, Heroes, however, cannot unlearn powers.
Great Powers are the ultimate magical abilities of the Mage empires. The casting of a great power not only takes time, but it consumes the magical stores of a nation, so the decision to utilize a Great Power must be thought out carefully. Great Powers can only be cast in battle if there is a Spellcasting hero in the battlefield, and must be assigned as a power would, taking up a spell slot, however, only one Great Power can be assigned to a Hero. Furthermore, some great powers can also be cast in the main territorial map and can change the face of the world.