In the land of Azeroth there has been peace for many generations. There is one boy, Medivh who is son of the court Conjurer, who is one night troubled by dark dreams resulting in the death of his father and a long sleep for himself. When he woke up he had become a powerful sorcerer and created an hourglass that would never empty as long as there would be peace. Meanwhile the orcs in another world started experimenting with a dimensional rift to Azeroth. Eventually they came through the rift with large numbers of soldiers and the hourglass emptied... The game starts some time after the orcs started ravaging the land of Azeroth. You play either humans or orcs in the war and your goal is to claim dominance over the whole of Azeroth.