Mankind is a morality play in 914 lines, preserved incomplete. Lacking are a single leaf within the manuscript and probably two or more leaves before the present beginning of the text. Its principal theme is Sloth (Accidia). It is written in low style and frequently shows obscenity:

The play opens with a sermon by Mercy, Mankind's spiritual adviser, who beseeches the audience to incline to Christ. Man must be stable in good works and resist corruption by the devil: his salvation depends upon the mercy exemplified in Christ's sacrifice. Intruding on this sermon, Mischief mocks Mercy's preaching, and is joined by New Guise, Nowadays, and Nought, who revel in the "ydyll language" of the world.

After the worldlings go out, Mankind approaches Mercy and learns that he must resist his three enemies - his own flesh, the worldlings, and most of all the devil Titivillus. Mankind accordingly sets to work tilling the soil, and succeeds to resist Titivillus, whom Mischief and the worldlings call in to their aid. Unseen by Mankind, Titivillus uses tricks to make him grow tired of labour and prayer and hold a mock court at which Mankind swears to follow their example of thievery, lechery, and murder. Urged on by his tempters, Mankind is about to hang himself in despair, when Mercy intervenes and persuades him to seek forgiveness through confession.