Prologues, as in Chaucer's Canterbury Tales, introduce motifs and tone; they appear to engage audiences, justify the work, or frame expectations, essential for epic or dramatic poetry to build narrative authority.

The prologue serves as an introductory poem or section that establishes context, previews themes, introduces characters or situations, and creates a threshold between the world outside the text and the world within. Unlike exordia (which primarily capture attention), prologues provide substantive orientation. Chaucer's Canterbury Tales uses the General Prologue to introduce pilgrims and frame the tale-telling contest. Shakespeare's prologues both provide plot information and establish theatrical conventions (Romeo and Juliet's prologue reveals the ending while soliciting audience patience). The technique allows poets to guide reader expectations, establish tone and register, and provide information that main narratives cannot easily convey. Prologues can be in a different voice or mode than the main text—a prose prologue before verse narrative, an authorial voice before dramatic monologues. Contemporary poets use prologues variously: some follow tradition by establishing context, others create ironic distance by promising one thing and delivering another. Students should examine what prologues accomplish that poems proper cannot, and how they shape subsequent reading. Understanding prologues reveals how poems announce themselves and negotiate entry into imaginative worlds.