One dominant literary device in Oedipus Rex is the use of flashbacks. A flashback is a moment in the narration when the present is interrupted to refer to the past. Flashbacks can especially be used to fill in background information surrounding a character, and they can be delivered through a "character's memories, dreams, narration, or even authorial commentary" (Wheeler, "Literature Vocabulary"). We see flashbacks being used in several places with the intention of giving background information and developing characterization. We see the first instance of flashback used when the priest recounts how Oedipus rescued Thebes from a plague before and, therefore, can do it again. Oedipus rescued the Thebans from the plague of the Sphinx who was devouring every citizen who could not answer its riddle, as we see in the priest's lines, "It was you who came and released Cadmus' town from the tribute we paid to the cruel songstress" (39-40). In these lines, "cruel songstress" refers to the Sphinx, showing us that these lines serve as a flashback to tell the reader/viewer about the time Oedipus rescued the city from its earlier plague.
Another dominant literary device is the use of imagery. Strong sensory imagery is found all throughout the play. For instance, when Oedipus describes the condition of the Thebans in his opening speech, he uses many sensory images to describe the smell and sound of their suffering, as we see in his lines, "All around the city is filled with the smell of incense, and around filled with the sound of hymns and groans" (3-5). Since incense is used in prayer, we know that the whole city is in supplication to the gods asking them to heal their city. Therefore, the reference to the smell of incense conjures up the image of pious petitions, helping us to see the condition of the city's people. In addition, the image of the "sound of hymns and groans" is another sensory image that allows us to both hear the people's pious petitions through hymns, but also their moans of agony.