Wizard players can now use spells during tactical combat. Not all spells can be used during combat – at the moment only Lightning Bolt, Chaos Bolt and Berserker Rush can be used this way.
There is a new button on the interface “Cast Spell” – it will bring up a list of spells. Pick one then click on the target. Currently there is no mana cost for tactical spell casting, but there is a cooldown of a couple of turns.