As the play begins, the King of Navarre and his three lords, Berowne, Longaville, and Dumaine, discuss the founding of their academe, or academy. The King reflects on the goal of their scholarship, primarily fame. He then asks the three lords to sign their names to the oath, swearing their commitment to the academe for three years. Longaville and Dumaine agree, but Berowne has issues with the strictness of the oath. He questions the necessity of the oath's requirements for fasting, little sleep, and the avoidance of women, calling them "barren tasks, too hard to keep,/ Not to see ladies, study, fast, not sleep" (I.i.47-8). He argues this point with the King, but finally agrees to sign the oath.
Berowne then begins to read the text of the decrees. He begins, "[I]f any man be seen to talk with a woman within the term of three years, he shall endure such public shame as the reset of the court can possible devise" (I.i.129-32). He points out that the King is going to break this article himself, since the daughter of the French king is about to pay a visit to their court. The King says that this decree must be forsworn "on mere necessity" (I.i.148). Berowne says that he has no problem subscribing to a decree that can be forsworn on mere necessity, and he signs the document.
The constable Dull enters with a letter and the fool, Costard. He tells them that he has a letter from Don Armado, and Costard tells them that the letter concerns him and Jaquenetta. The King reads the letter, in which Armado informs him that he has caught Costard consorting with Jaquenetta and has thereby sent him to the King for punishment. Costard tries to escape with clever wordplay, but he fails and is sentenced to a week of only bran and water.
Don Armado confesses to his page, Moth, that he has fallen in love with Jaquenetta. He asks Moth to comfort him by telling him of other great men that have been in love, and Moth mentions Hercules and Samson. Dull returns with Costard and Jaquenetta and tells Armado that the King has sent Costard to serve his sentence. Armado tells Jaquenetta that he loves her, but she departs with Dull. Armado sends Costard with Moth to be imprisoned and, when alone, laments that his oath will be forsworn through his love for Jaquenetta. He then begins to write.
The King's opening lines illustrate the primary goals for establishing his academe: "Let fame, that all hunt after in their lives,/ Live regist'red upon our brazen tombs" (I.i.1-2). He says, "Navarre shall be the wonder of the world" (I.i.12), suggesting that he seeks knowledge not for its own sake but to further the fame of his court.
Berowne's attempts to convince the King that the oath is too strict and severe show how language functions as a tool in the play. Berowne tries to talk his way out of the parts of the oath he does not like, but this time the King is not convinced. The King and the other two lords note the paradoxical nature of Berowne's reasoning:
KING: How well he's read, to reason against reading!
DUMAINE: Proceeded well, to stop all good proceeding!
LONGAVILLE: He weeds the corn, and still lets grow the weeding
Berowne will use rhetoric later to justify other contradictory conclusions--for example, when he reasons that the courtship of the Princess and her ladies does not violate their oath (see IV.iii.286-362).
When Costard, the fool, is caught courting Jaquenetta by Don Armado, he tries to reason his way out of the punishment by arguing that Jaquenetta is not a wench but a damsel, not a damsel but a virgin, and finally not a virgin but a maid. The King, however, informs him that these classifications all fall under the same decree and punishes him anyway. The defeat of Costard's reasoning and his punishment for courting Jaquenetta warn the King and lords to avoid duplicitous rhetoric and scheming women. Unfortunately, they choose not to heed this warning, and so become entangled in similar situations again.