Piers Plowman is considered to be one of the most analytically challenging texts in Middle English textual criticism. There are 50–56 surviving manuscripts, some of which are fragmentary. None of the texts are known to be in the author's own hand, and none of them derive directly from any of the others.
All modern discussion of the text revolves around the classifications of W. W. Skeat. Skeat argued that there are as many as ten forms of the poem, but only three are to be considered authoritative—the A, B, and C-texts—although the definition of "authoritative" in this context is problematic. According to the three-version hypothesis, each version represents different manuscript traditions deriving from three distinct and successive stages of authorial revision. Although precise dating is debated, the A, B, and C texts are now commonly thought of as the progressive (20–25 years) work of a single author.
According to the three versions hypothesis, the A-text was written c. 1367–70 and is the earliest. It breaks off, apparently unfinished, at Book 11 and Book 12 is written by another author or interpolator. The poem runs to about 2,500 lines. The B-text (Warner's ur-B text) was written c. 1377–79; it revises A, adds new material, and is three times the length of A. It runs to about 7,300 lines. The C-text was written in the 1380s as a major revision of B except for the final sections. There is some debate over whether the poem can be regarded as finished or not. It entails additions, omissions, and transpositions; it is not significantly different in size from B. Some scholars see it as a conservative revision of B that aims at disassociating the poem from Lollardy and the religious and political radicalism of John Ball during the Great Rising of 1381. (Ball appropriated Piers and other characters in the poem for his own verses, speeches, and letters during the Rising.) There is little actual evidence for this proposal, and much against it.
Skeat believed that the A-text was incomplete and based his editions on a B-text manuscript (Oxford, MS. Laud Misc. 581) that he wrongly thought was probably a holograph. Modern editors following Skeat, such as George Kane and E. Talbot Donaldson, have maintained the basic tenets of Skeat's work: there were three final authorial texts, now lost, that can be reconstructed, albeit imperfectly and without certainty, by rooting out the "corruption" and "damage" done by scribes.
The Kane, Kane-Donaldson, and Russell-Kane editions of the three versions, published by the Athlone Press, have been controversial, but are considered among the most important accomplishments in modern editorial work and theory in Middle English. A. V. C. Schmidt has also published a parallel edition of A, B, C and Z; the second volume contains a full critical apparatus indicating his editorial decisions was finally published in 2008, long after the first volume fell out of print.
A. G. Rigg and Charlotte Brewer hypothesized the existence of a Z-text predecessor to A which contains elements of both A and C. The Z-text is based on Oxford MS. Bodley 851, which Rigg and Brewer edited and published. It is the shortest version, and its authenticity is disputed. Ralph Hanna III has disputed the Rigg/Brewer approach based on codicological evidence and internal literary evidence; consequently the Z-text is now more commonly viewed as a scribal corruption of A with C elements. More recently, Lawrence Warner has shown that what was thought of as B in fact incorporates matter produced as part of the C-revision: if B circulated before C, it looked nothing like what previous editors had assumed.