SCENE I. Rochester. An inn yard about 25 miles from London.
Enter a Carrier. He calls to his hostler. A second Carrier enters and the two talk in a colloquial English vernacular, virtually unintelligible to modern readers, for some time waiting for the hostler to come out. Gadshill enters and implores if he can barrow one of the Carriers’ lanterns. They deny his request thinking that he is up to some or other trickery. The Carriers leave and the Chamberlain of the inn (Gadshill’s informant) enters. The informant tells Gadshill that a party of the King’s men carrying money for the exchequer are presently having breakfast at the inn and will be starting their day’s journey soon. Gadshill asks the Chamberlain if he would like to take part in the robbery; however, the Chamberlain rejects the invitation and a brief spat ensues between them.
SCENE II. A highway near Gadshill.
Enter Prince Henry, Poins and Falstaff. They are waiting near the highway whereupon they know their victims will be passing. Poins has hidden Falstaff’s horse and Falstaff complains vociferously.
Gadshill, Bardolph, and Peto enter and inform the party that their prey is coming. Henry tells them that he and Poins will detach and approach their target from the side, so as to make sure that no one escapes. Poins tells Falstaff that his horse is behind a nearby hedge, which it is not. Poins and Henry leave.
The travelers enter, promptly get robbed, and are carried off by Falstaff and the others. Henry and Poins, in disguise, reenter; soon Falstaff and the others reenter and are incidentally robbed by Henry and Poins. Dropping all the booty, none of them put up any fight—only Falstaff throws in a punch or two. Henry and Poins laugh at Falstaff; they know he will be greatly upset when he finds out that they have gotten rid of his horse. Henry jests: “[he] lards the lean earth as he walks along” and says “were [it] not for laughing, I should pity him.”
SCENE III. Warkworth Castle, home of Hotspur.
Enter Hotspur reading aloud a letter and adding his commentary. The letter is from a nobleman which Hotspur has asked for support from in the Percy’s cause. The letter is a refusal, however, saying that the rebellion is not sufficiently planned out and that their cohorts are not sufficiently strong. Angry, Hotspur condemns the nobleman for being a coward, though fearing that the nobleman will disclose the plot to Henry, Hotspur decides that he must put the rebellion into action that night.
At this point Lady Percy, also called Kate, enters. Hotspur tells her that he will be leaving the castle within two hours. Upset, she attempts to interrogate Hotspur as to why he’s been acting so strange lately. She asks him why he hasn’t been eating properly, sleeping well, making love to her, and why he’s been talking in his sleep; her endeavor is quite fruitless. Furious at Hotspur for ignoring her, she starts to demand answers; she suspects that all his recent peculiarity has to do something with Mortimer’s claim to the throne.
Impatient Hotspur tells Kate that he does not love her anymore, that this world is no place “to play with mammets (dolls) and to tilt with lips (kiss),” but, rather, that there must be bloodshed and war. He insists that he will not tell her what his intentions are because he does not trust the gossipy species of women. He tells her that she will not be able to reveal what she does not know. He tells her that he shall call for her the next day so that she can follow him on horseback. Unable to bargain, Kate must consent to her husband’s decisions.
SCENE IV. The Boar’s-Head Tavern in Eastcheap.
Enter Prince Henry and Poins. Henry has been making friends with the bartenders who have dubbed him the “king of courtesy.” He has learnt their names and slang and is rather pleased with himself. Henry and Poins decide to pass the time by teasing a young trainee bartender named Francis.
Falstaff, flustered and demanding his alcohol, and the others arrive whereupon Falstaff tells the tale of their robbery. His outrageous lies are outrageously funny; first he claims that they were robbed by one-hundred men. However, the number of men in the story is consistently inconsistent; by and by, annoyed Henry discloses that he and Poins were the ones who actually robbed them. Quick-witted Falstaff claims that he knew this fact all along and ran away to avoid having to hurt Henry, but that he is pleased Henry and Poins have the money since now they can pay for everyone to get drinks.
Mistress Quickly, the Hostess, enters and tells Henry that someone outside brings him news. Falstaff goes to get rid of the man for Henry but comes back with news that civil war has gripped England, that the Percy’s have joined together to dethrone King Henry, and that the Prince must go to court to talk to his father the next morning. Worried about the upcoming encounter, Falstaff and Henry decide to role play. Falstaff first assumes the role of the King, but unable to play the role without making it personal, Henry proposes they switch roles; they switch roles but Falstaff is still unable to take it seriously.
Their role playing is interrupted when a sheriff arrives at the tavern looking for some thieves who robbed some travelers that morning. Henry instructs Falstaff to hid, which he does, the sheriff enters and Henry tells him that he has no information but will personally see to it that the thieves are caught and punished. The sheriff leaves and Henry finds Falstaff sleeping in his hiding place; replying to Falstaff’s ungracious gesture, Henry pickpockets him but finds nothing of value. Henry then tells Peto that he must answer his father's summons in the morning and that all of them must fight in the war. As a joke, he decides that he will put Falstaff in charge of a brigade of foot soldiers.