Portia is a wealthy, beautiful, and intelligent heiress. Her father has died. In his will, he has stipulated that she not choose her own husband. Instead, he has set up a "test" for her prospective suitors.
To win Portia's hand in marriage, the man who wishes to be her husband must first choose one of three caskets. One casket is gold, one silver, and one lead. If the suitor chooses correctly, he has the right to marry Portia, whether she likes it or not.
Portia complains about having no control over one of the most important decisions in her life. Shakespeare, who understood how women were tyrannized in his culture, later shows how capable of judgment and decision-making Portia is, when she disguises herself as a man and successfully pleads Antonio's case in court.