King Ferdinand of Navarre and his three closest lords—Biron, Dumain and Longaville—have taken a vow abstinence from the sensual pleasures of life to devote three years to the pursuit of knowledge. This task will involve isolated themselves in the court with extreme limitation upon contact with ladies of the court. The only one of the four exhibiting doubt about the plan is Biron, but finally he too signs the oath. Wouldn’t you know this signing is coincident with a visit from the Princess of France.
Meanwhile, Constable Dull arrives with news about a criminal act by a man named Costard: flirting with an innocent country girl. Costard is punished for this transgression with Don Armado the enforcer.
The Princess arrives and is taken aback by the rather inhospitable treatment. The King and his lords arrive and each is instantly smith with the Princess or one of her ladies. Biron pressures Costard into delivering love letter to Rosaline, one of those ladies. Costard has also become the messenger for a letter from Don Armado to lady Jaquenetta. Bad decision by both men, as Costard gets the letters confused and winds up delivering them to the wrong lady.
The results are some comical confusions regarding who loves who and plenty of told-you-so moments from Biron who felt the whole premise of trying to spend three years studying without giving into the temptations of the flesh was hopelessly doomed from the beginning. The climax begins with the males disguising themselves as Russians in order to play a trick upon them, but the women are to cunning and after discovering their plans beforehand, set about making sure each lord sets to wooing the unintended object of his affection.
The fluffy tone of light banter and clever repartee suddenly changes when news arrives for the Princess that her father as died. They women prepare to head back to France amid affirmations of sincerity in their love from the men. An agreement is made that if they men are really serious, they must take another vow to commit to certain practices for another year.