The virtue of marriage is very important for Shakespeare, who often ends his comedies with multiple marriages to signify a happy solution to many of the problems the characters have faced. Marriage is thus a way of achieving inclusion for Shakespeare, and it is notable that the characters which remain unmarried are often isolated and removed from the society, specifically Antonio and Shylock within this play. Marriage also represents a way to overcome difficulties; for Bassanio it will remove his debt, for Portia it will free her from her father's will and for Jessica is will allow her to escape her father.

Given this view of marriage, the choice of the caskets presents a horrifying risk for many of the participants, namely the threat that if they choose wrong casket they must swear to never propose marriage to a woman afterwards. In a sense, the failure to marry is as good as being castrated. In fact, Shakespeare creates this very analogy throughout The Merchant of Venice and ties it to the ability to make money breed. Thus in the first act Shylock mentions that he makes his money breed as fast as ewes and lambs. Antonio will further this metaphor in the final act, when he remarks that he is like a wether, or a castrated lamb, and thus unable to breed. For the suitors to Portia, then, swearing to never wed puts them on the same level as Antonio. By agreeing to not marry, they themselves become castrated.

Lancelot the clown is one of the more interesting characters. His treatment of his father is awful, considering that his father is mostly blind and has brought a present to his son. The entire scene mimics the biblical story of Jacob and Esau, though. The bible tells how Jacob tricked his father into giving him the inheritance by wearing wool so his father would think he was Esau. Lancelot does the same thing, by bending down and making his father "know" him by feeling his head.

Shylock's character starts to emerge very strongly within this act. We see him now not only as a moneylender demanding interest, but also as a villain. He shows a marked aversion to fun, demanding that Jessica lock the door and close the windows when he finds out there will be a masque that night. However, contrary to his statement in the first act, Shylock leaves his house to enjoy a dinner with Bassanio. Much of this act therefore develops the negative aspects of Shylock character.

However, the Christian faults are also exposed within this act. The faithlessness of Jessica has been an issue of discussion for many centuries, with the debate raging over whether she is justified in leaving her father. The crucial difficulty is that she does not merely run away, but she insists on stealing large amounts of her father's jewels and gold. Thus when Graziano remarks, "Now, by my hood, a gentile, and no Jew", we can only see it as ironic. Ironic because she is stealing her father's money, so he is essentially implying Christians are thieves.

Jessica's actions also leave unanswered the question of why she is locked up in her father's home. The answer to this comes from an understanding of the relationship between money and breeding. Whereas in the beginning Antonio is impotent in the sense that his money does not breed, Shylock is not. Shylock further has the advantage of having a daughter. Since the Jewish lineage is passed down via the maternal line, Jessica represents a way for Shylock's family line to continue. Thus, hoarding Jessica and his gold is Shylock's way of guaranteeing his successful breeding. In fact, Solanio makes this connection between daughter and money abundantly clear when he tells us that Shylock ran through the street of Venice crying:

"My daughter! O, my ducats! O, my daughter!

Fled with a Christian! O, my Christian ducats!

Justice! The law! My ducats and my daughter!

A sealed bag, two sealed bags of ducats,"

Thus for Shylock the simultaneous loss of his daughter and his money is in a sense the loss of his fertility.

Not only does her conversion to Christianity destroy Shylock's family line, it also makes him impotent in a metaphorical sense. Jessica takes two stones with her, which represent the "testicles" of Shylock, since stone was often used to mean testicle. Thus after her theft, Shylock joins Antonio in impotence, having lost his ability to breed. Indeed, the escape of Jessica marks the turning point of Shylock's fortunes, which will lead to his eventual destruction.

It is important that Jessica escapes not dressed as herself, but as a man. In fact, there is a never a scene on the Venetian streets in which a woman is present. The only way a woman can walk through the street of Venice is to dress as a man, a fact that will reinforced when Portia pretends to be Balthasar and dresses as a man before entering Venice. This is one of the primary differences between the worlds of Venice and Belmont.

The three caskets each bear inscriptions that tell us about the personalities of the characters who pick them. Gold reads: "Who chooseth me shall gain what many men desire". The silver casket has, "Who chooseth me shall get as much as he deserves". Finally, the dull lead casket bears the inscription, "Who chooseth me must give and hazard all he hath". The Prince of Morocco first chooses gold and gets a death skull. The Prince of Aragon receives the picture of an idiot. This is symbolic, for he is an old man and hence is an idiot for thinking himself deserving of a young woman.

One of the most debated lines is when Portia sends the Prince of Morocco away by saying, "A gentle riddance. Draw the curtains, go. / Let all of his complexion choose me so". This provincial comment stands in contrast with her upbringing and nobility. However, what soon becomes clear is that Portia is a very narrow character in her sense of friends. She chooses Bassanio over the more cosmopolitan suitors because he represents her Christian and Venetian world. Bassanio wins her because of the same thing, namely he alone of the suitors possesses the local characteristics necessary to interpret which casket to choose.

Unlike Portia and Bassanio, Jessica never has to be chosen by a casket. Instead, she tosses her casket out of the window for Lorenzo to catch. Thus her relationship, unlike that of Portia and Bassanio, has no test to make sure it is a good relationship. This lack of a test will create problems later, foreshadowed by Shakespeare when Lorenzo and Jessica compare themselves to many famous failed romances.

The Merchant of Venice is largely a play about interpretation. The suitors to Portia are condemned to sterility because they misread the caskets. Shylock's interpretation of the contract in Act I Scene 3 takes the "pound of flesh" seriously and literally, whereas Antonio thinks Shylock is being "kind." Later in the final scene, the outcome of the play - whether it becomes a comedic ending or a tragic one, will rest on Portia's interpretation of the law. Thus the play creates its drama and its plot through the constant interpretation of events and words. This crucial aspect is frequently used by Shakespeare in his remaining comedies, and it forms a crucial part of the plot in Much Ado About Nothing.