The poem—part theological allegory, part social satire—concerns the narrator's intense quest for the true Christian life, from the perspective of medieval Catholicism. This quest entails a series of dream-visions and an examination into the lives of three allegorical characters, Dowel ("Do-Well"), Dobet ("Do-Better"), and Dobest ("Do-Best"). The following summary is based on the B-version of the poem--the most widely edited and translated.
The poem is divided into passus ('steps').
Prologue: The poem begins in the Malvern Hills between Worcestershire and Herefordshire. A man named Will (which can be understood simply as a personal name or as an allegory for a person's will, in the sense of 'desire, intention') falls asleep and has a vision of a tower set upon a hill and a fortress (donjon) in a deep valley; between these symbols of heaven and hell is a "fair field full of folk", representing the world of mankind. A satirical account of different sections of society follows, along with a dream-like fable representing the King as a cat and his people as rodents.
Passus 1: Holy Church visits Will and explains the tower of Truth, and discusses Truth more generally.
Passus 2: Will sees Lady Mede ('payment') and finds out about her planned marriage to False.
Passus 3: Lady Mede travels to the royal court; the King proposes she marry Conscience; but Conscience denounces her.
Passus 4: Conscience and Reason convince the King not to marry Mede to False. Will wakes up.
Passus 5: Will falls back to sleep. Reason gives a sermon to the Field of Folk and the people decide to repent. The Seven Deadly Sins make confession and in penance attempt to go on pilgrimage to St Truth. They get lost, and Piers Plowman makes his first appearance: he will help the penitents if they help him plough his half-acre.
Passus 6: Piers and the penitents plough the half-acre. Some people refuse to work, and Hunger punishes them until they work. But once Hunger has been sated, the people return to idleness.
Passus 7: Eventually, Truth sends Piers a pardon for the penitents' sins; its main content is 'Do well and have well and God shall have your soul' and 'Do evil and have evil, and expect nothing other than that after your death, the Devil shall have your soul'. When challenged on the pardon's validity by a priest, Piers angrily tears it in two. Will is awaked by their arguing and, musing on his dreams, decides to seek ‘Do-wel’.
The A-version of Piers Plowman stops at this point.
Passus 8: Will's search for Dowel begins. He enters into a disputation with Friars. He then falls asleep once more and meets Thought. Thought instructs Will in 'Do well, do better, do best'. Practical interpretation of what these concepts mean is to be provided by Wit.
Passus 9: There is an extended allegory featuring Dowel and the Castle of Flesh, exposing the need for people to be governed by their ‘Inwit’. The text discusses poverty and marriage. Wit makes further inroads to understanding Dowel, as active virtue.
Passus 10: We meet Wit’s wife, Dame Study. She complains to Will about his ignorance. Will then proceeds to Clergy and Scripture to learn more about Dowel. He considers what use scholarship might have in helping him achieve salvation.
Passus 11: Scripture complains about Will's lack of self-knowledge. Angered, Will (who is already dreaming) goes to sleep and has a dream-within-a-dream in which he meets Fortune. He serves her into old age, but she abandons him. Will learns about the salvation of the Emperor Trajan and power of love. Kynde ('character, natural disposition, nature', here understood as an aspect of God) shows Will the world. Will has an argument with Reason: Reason, Will concludes, does not do enough to keep people from sin; but Reason disagrees. Will awakes from the dream-within-a-dream. He now meets meets Imaginatif, who advises Will to be patient.
Passus 12: Imaginatif teaches Will, bringing together and improving his understanding of earlier discussions in the poem.. Imaginatif emphasises the need for humilty and the importance of Grace.
Passus 13: Will awakens and then falls back to sleep; he dreams of sharing a feast with Conscience, Scripture, Clergy and Patience; he encounters a greedy Doctor of Divinity (who later shows disdain for love) and as well as eating actual food also dines on spiritual food. Piers the Plowman offers a definition of Do Well, Do Better and Do Best. Then Conscience and Patience meet Haukyn the Active Man, who wears a coat of Christian faith which is, however, soiled with the Seven Deadly Sins.
Passus 14: Conscience teaches Haukyn to seek forgiveness and do penance; Patience teaches Haukyn about the merits of embracing poverty. Haukyn cries out for God's mercy, which awakens Will.
Passus 15: Will finds himself alienated from the waking world, but Reason helps him to go back to sleep, whereupon Will meets Anima ('spirit'). Anima tells Will off for his pride in wanting to know too much, but goes on to talk about charity, in particular how the Church should care for its flock, but how its priests and monks (among whom Langland counts the Prophet Mohammed) do not always fulfil this duty. Talking to Anima, Will starts to conclude that Piers the Plowman is Christ. Will realises that he needs to switch from searching for Dowel to searching for Charity.
Passus 16: Will falls into another dream-within-a-dream, this time about the Tree of Charity, whose gardener is Piers the Plowman. Will participates in a re-enactment of the Fall of Man and then has a vision of the life of Christ; when this reaches the point where the Devil is defeated, Will wakes up from the dream-within-a-dream. Will goes looking for Piers and meeting Faith/Abraham, who is himself searching for Christ.
Passus 17: Next, Will meets Hope/Moses, characterised by the tablets of law and is also in search of Christ. Will learns about the Good Samaritan, the propsect of salvation, and the importance of Love. He wakes up.
Passus 18: Will sleeps again, and experiences the climactic section of Piers Plowman. He experiences Love and the intersection of human and divine time. Will witnesses Christ/the Good Samaritan/Piers Plowman riding into Jerusalem and Christ's crucifixion. He then witnesses the Four Daughters of God (Truth, Justice, Mercy, Peace) in debate; the Harrowing of Hell; and Redemption.
Will wakes again, and now exhorts his family to attend mass.
Passus 19: During the mass, Will falls back to sleep and meets Conscience once more. Conscience recounts the life and Passion of Christ and how Piers/Peter was given his power by Grace/Christ. Will finds out about Pentecost; once more sees Piers as a ploughman; and witnesses Pride attacking Unity/Holy Church. He wakes up and records his dream.
Passus 20: While awake, Will meets Need. He falls asleep again and now dreams of the Antichrist. Kynde sends Old Age, Death, and Pestilence, to chastise people: Will is attacked by Old Age. He witnesses Holy Church undermined by a hypocritical Friar. Conscience goes on pilgrimage to seek Piers the Plowman, and calls on Grace for help--whereupon Will wakes up.
Version C has a further two passus.