Spells are a type of Artifact card and are played during the Action Phase of a round. They are the most varied type of card in their effects, including being able to summon Creeps, apply modifications or status effects to units, deal Damage, move or redirect units, and much more. They are the main method of interacting with the board.
Costs and Restrictions
Every spell has an associated Mana cost which must be paid from your tower's Mana pool in the current lane to cast the spell.