The structure in essence is a 'play within a play'. The play begins with the background of why Hieronimo wants to seek revenge. He is seen as a minor character and eventually leads up to being the protagonist to add to the revenge plot. When he becomes the main character, the plot begins to unfold and become the revenge story that it is. Kyd incorporates the buildup to the revenge as a way to show the internal and external struggles of the characters. The actual revenge takes place during the play that Hieronimo stages, making this the climax of the play. The resolution is essentially the explanation to the king of what has happened. The play within the play is not described until the actual play is performed, intensifying the climax, and the resolution is short due to the explanations that have already occurred.
Critics say that The Spanish Tragedy resembles a Senecan Tragedy. The separation of acts, the emphasised bloody climax, and the revenge itself, make this play resemble some of the most famous ancient plays. Kyd does acknowledge his relations to Senecan Tragedies by using Latin directly in the play but also causes Christianity to conflict with pagan ideals. We also see Kyd’s use of Seneca through his referencing three Senecan plays in The Spanish Tragedy. It is said that this play was the initiator of the style for many “Elizabethan revenge tragedies, most notably Hamlet”.