Spells

Spells are a powerful ability of Major Units who have them and they share only a distant relationship with the aforementioned Magic Attack. Every Major Unit who has any Magic Attack will have at least one spell. If the unit has 10 to 19 Magic Attack, they get 2 spells, 20..29 - 3 spells, and so on up to maximum of 5 spells.  In order to cast a spell, the empire must have enough manna.  The Magic User uses arcane rituals to tap into this source of energy.  In the Spell List you see a cost column. This is the Manna Cost for this spell.  The Empire receives one manna point per city per turn. Cities surrounded by swamps receive an extra manna point for every swamp square within two squares of the city.

Right now there are three categories of spells: attack,  bless, and other.  They differentiate in how they are cast and how they are "bill" the manna so to speak.