Fate is a dominant strand in the overall pattern of Calderón's dramatic world; and not only in the comedias, because the struggle against the fulfilling of prophecies has its counterpart in the autos sacramentales, where the Devil and his confederates, perpetually disturbed by the Messianic promises, conjure up the enactment of future events in order to try to prevent their implementation, only to find no hope of escape from the fate in which they are trapped. Fateful predictions are not absent from Lope's plays, but they would seem to be part of the machinery to set the action in motion rather than its inner motivation. They represent no problematic element in life for the plays' themes to explore. For Calderón, on the other hand, el hado is clearly something that men must come to terms with, both for their general understanding of existence and for the practical task of ethical living. Fate and what is bound up with it (principally la fortuna and el desengaño) may therefore be considered the most problematical element in Calderón's world.

Peter Berens attempted to analyse the meaning of Calderonian fate sixty years ago, but his laudable effort suffers today from the general inadequacy of Calderonian criticism at that time, in particular from the failure to see how important are all the details in the structure of individual plots, and how varied these are because of these details.