Life is a Dream (Spanish: La vida es sueño) is a Spanish language play by Pedro Calderón de la Barca. First published in 1635 (or possibly early in 1636), it is a philosophical allegory regarding the human situation and the mystery of life. Focusing on Segismundo, Prince of Poland, the central argument is the conflict between free will and fate. The play remains one of de la Barca's best-known and most studied works.
In the play, the king of Poland has had his son Segismundo imprisoned all of his life because it has been prophesied that the son will bring disaster to the country. The king tells his subjects that his son died after childbirth. After his son has grown to be a man, the king reveals to his court that his son lives, and allows the court to vote in favor of allowing the son to become heir. However, the son turns out to be violent, killing a man and attempting rape. For this he is drugged and returned to his prison, and told upon waking that the previous day's events were merely a dream. Still, his jailer scolds him for his un-princely behaviour, which prompts remorse in Segismundo. Rebels who are working against the king, who have found out about the treatment of Segismundo, break him out of prison. The rebels defeat the king's army; however, Segismundo doubts again if he is in reality or a dream, finally deciding that even in a dream we have to behave well because "God is God" and forgives the king . The play ends in a wedding.