The play makes use of various theatrical devices, some of them derived from Senecan Tragedy which includes violence and bloodshed on the stage. Act III, Scene IV is a mime scene in which a song is sung in honour of the Cardinal who gives up his robes and invests himself with the attire of a soldier and then does the act of banishing the Duchess. The whole scene is commented upon by two pilgrims who condemn the harsh behaviour of the Cardinal toward the Duchess. That the scene is set against the backdrop of the Shrine of Our Lady of Loretto, a religious place, adds to its sharp distinction between good and evil, and justice and injustice.
Act V, Scene iii, features an important theatrical device, echo which seems to emanate from the grave of the Duchess and is also in her voice. Combined together it reads: "Deadly accent. A thing of sorrow. That suits it best. Ay, wife's voice. Be mindful of thy safety. O fly your fate. Thou art a dead thing. Never see her more." The echo repeats the last words of what Antonio and Delio speak but is selective. It adds to the feeling of inevitability of Antonio's death while highlighting the role of fate.