Electra, the protagonist of the drama, has an extremely complex role in that the principles of justice and honor to which she so stubbornly adheres require her to do the unthinkable—to participate in her mother's death. What adds to the inherent complexity of Electra's position is the increasing evidence throughout the play of the uncertainty of Electra's grasp on the very standards of justice that motivate her.
It is clear from the outset that Electra is right to mourn her father's murder by her mother. Her mourning is a natural response to an awful occurrence, and she claims that although she does not necessarily choose grief, she feels forced, as if by the principles of honor, to act as she does. Electra's mourning results in her abuse by both Clytemnestra and Aegisthus, who, perhaps threatened by Electra's refusal to let go of the past, treat her as little better than a slave in her own house. Electra is willing to suffer in the name of honor, and, in the name of justice, she rightfully longs to avenge her father's death. Yet Electra soon undermines her position in her initial encounter with Clytemnestra. Clytemnestra insists that she murdered Agamemnon to exact revenge for his sacrifice of their daughter. Electra counters by arguing that justice cannot be achieved by answering a killing with another killing but this raises questions about the integrity of Electra's character for Electra herself longs to avenge her father's death.
Electra's character is called into further question as the play progresses. After Orestes has revealed his true identity to her, her enthusiasm at the prospect of finally exacting revenge snowballs, and she seems to lose an element of rationality, demonstrating a profound contradiction to her initial insistence on justice and honor. Electra cries out for further violence as she listens to Orestes deal fatal blows to Clytemnestra, and she baits Aegisthus as he returns home, feigning a humbleness that she sadistically turns on its head as soon as Aegisthus realizes he is trapped. She denies Aegisthus the right to speak before he dies, and she advocates leaving his corpse out for scavengers to eat. Initially the exclusive vehicle for justice and honor, Electra becomes filled with contradictions that render the play morally ambiguous.
Still quite youthful when instructed by Apollo's oracle to avenge Agamemnon's murder, Orestes displays a level of immaturity that renders the ultimate revenge—the serious matter of matricide—morally ambiguous. His initial uneasiness about lying about his own death suggests a certain level of childish superstition, and his lie of choice—that he was killed in a chariot race—reflects the naiveté of both youth and wealth. His desire to avenge his father's death is not motivated by intense emotion or the principles of honor or justice. Orestes acts as he does because he has been so instructed by the oracle of Apollo.
Orestes's inexperience reveals itself on several occasions. When at first he hears Electra crying within the house, he expresses a desire to greet her immediately, already demonstrating a tendency to wander from the task at hand, which, as the Old Man reminds him, is to set the plan for revenge in motion. When he finally does meet Electra, he is unable to conceal his identity from her for long. He jeopardizes the secrecy of his plan by letting her know who he is, for which the Old Man scolds him. Once he has embarked on the actual act of revenge, however, Orestes's character does gain a level of maturity. Although still principally motivated by Apollo's instructions—insisting that the revenge is only as "good" as Apollo's oracle was "good"—he demonstrates an understanding of the justice at stake. He takes Aegisthus to kill him in the exact spot where Aegisthus murdered Agamemnon. Orestes' seeming maturation as the revenge unfolds compensates, in a sense, for Electra's increasing irrationality, but his initial immaturity and the cold source of his motivation make the audience shudder at the play's final outcome, wondering if what has happened is right.
Clytemnestra also adds to the complexity of the final revenge. Electra tells us that Clytemnestra is a cruel, pitiless, woman, a killer of her own husband who deserves to be punished for her actions. According to Electra, Clytemnestra killed Agamemnon so that she could be with Aegisthus. Clytemnestra, however, paints a very different picture of the murder. She says that she was exacting revenge for Agamemnon's unnecessary sacrifice of their daughter. If this is the case, the problem of revenge takes on a new shape. The unsettling ambiguity of Clytemnestra's motivation in killing Agamemnon calls into question the very need for revenge.
Clytemnestra's response to the news of Orestes' death is also unsettling. She prays that Orestes might never return to disrupt her life, but her reaction to his death is not one of unqualified delight. Her expression of maternal feelings, however brief, point a level of human decency and undermine Electra's villainous depiction of her. We cannot help but recall her brief expression of maternal pain and love as her own son stands above her, dealing her her fatal blows.