War
The play doesn't show any of the action of the battle where Eteocles and Polynices lose their lives. We do see the reaction to what is left in the wake of the loss in Antigone and Ismene though. This is a metaphor that war brings only death to a city and the families that belong to it.
Eteocles
Eteocles gives a speech to the people of his city at the opening of the play telling them to give glory to the gods in victory and for him to take all the blame in defeat. He appears to be a worthy ruler, but his speech is a metaphor for corruption as he is the reason the battle is occurring. He has denied his brother's rule, which it was agreed upon that they would rule in alternating years, thus he is the reason the city is under attack.
Curse
Polynices and Eteocles' deaths at the end of the play become a metaphor for the line of Oedipus being cursed. Once the truth of his life is discovered, Oedipus tears his eyes out and curses his sons. Because of his sins his sons will too be cursed, and this is fulfilled with their deaths.
King
Eteocles chooses to be the seventh soldier to face the challenger at the seventh gate. This is a metaphor for the fact that no one else can solve what he has set into motion by denying his brother's rule. It is a metaphor for his claiming responsibility for creating the battle.
Sisters
Antigone and Ismene speak at the end of the play, finishing one another's sentences. This is a metaphor for how the siblings are united in their grief at the loss of their two brothers on the same day.
