Act I, scene 1
Antonio, a Venetian merchant, complains that he is depressed but does not know why. His friends, Salerio and Solanio, suggest that he is worried about his commercial investments, but Antonio responds that his
money is invested in so many different products and ships that he has no specific worries. Solanio declares that he must be in love, but Antonio dismisses that suggestion as well. They encounter Bassanio and when the other leave, they are left alone. They are intimate friends and Bassanio is in debt with Antonio. The debtor now begs his friend to make him a final loan so that he can go to Belmont and court the rich heiress Portia. Antonio is willing, but says that all of his own money is tied up in ship cargoes. However, if Bassanio borrows money from someone, Antonio will provide security for the loan.

Act I, scene 2
At Belmont, Portia complains to her servant, Nerissa, that she is depressed, because according to her father's will, Portia cannot choose her own husband. Instead, suitors must select one of three caskets--one of gold, one of silver, and one of lead. If they choose the casket containing Portia's picture, they win her hand in marriage; but if
they choose wrongly, they suffer a penalty. Nerissa lists the suitors who have come already: a Neapolitan prince, a Palatine count, a French nobleman, an English baron, a Scottish lord, and the nephew of the Duke of
Saxony. Portia criticizes each of them--one likes his horse too much, one is a drunk, and so on.
All of these suitors have left without guessing, fearing the penalty if they fail. Portia is relieved that none of them tried to guess, and we learn that Portia and Nerissa wish that Bassanio, who has visited Belmont once
before, would guess successfully. At this moment, a servant enters to tell Portia that the Prince of Morocco will arrive soon to attempt the choice of caskets; Portia is not happy to hear the news.

Act I, scene 3
Shylock, a Jewish moneylender, agrees to loan Bassanio three thousand ducats, but asks to speak with Antonio first because he is offering security for the loan. When Antonio arrives, Shylock notes in an aside that
he hates this man--because he is a Christian, because he lends money without interest, and because he despises Jews. Shylock then asks how long the money will be lent for, and Bassanio tells him three months.
Shylock wonders why he should lend money to someone who has injured him.