A major dramatic device in Death and the Maiden is Dorfman's use of the mirror in Act 3, Scene 1. At the moment of the play's climax, the stage directions indicate that a giant mirror descends in front of Paulina and Roberto, forcing the audience to study themselves and each other while a spotlight roams around, illuminating various audience members in turn. This highly alienating device entirely takes the viewers out of the "story," encouraging them to instead reflect (literally) on their own feelings about the narrative - their complicity in violations of human rights, their belief in whether or not Paulina's actions are justified, and their own opinions about personal or societal justice.
In the play's final scene, the stage directions indicate that Paulina and Roberto are watching a concert from within the audience itself, which further serves to implicate the audience in the issues of the play - Dorfman literally "casts" the viewers as citizens of Paulina and Roberto's country, and forces them to consider how they might behave when put in the same situations as his fictional characters.
The use of music in the play - specifically, Schubert's Death and the Maiden and the Mozart piece that accompanies the climax - helps to intensify the emotional impact of the play by exposing the audience to the same auditory cues that torment Paulina.
Finally, the play's lighting cues as written in the stage directions also help to amp up the intensity. For example, the darkness that surrounds the tape recorder as we hear Roberto's confession focuses the audience's attention on the content of his confession, and the moonlight that illuminates Roberto at the end of the play underlines the haunting quality of his presence.