Fate refers to an occurrence that uncontrollably befalls a person. The Oracle Prophesies at Delphi dooms Oedipus the king prior to his birth; by prophesying that Oedipus would marry his mother and kill his father. Oedipus learns about the prophecy, but lands on this fate because of his arrogance. He makes a quest for the truth about his father because does not know about his origin. This forms a platform for the occurrence of the Oracle prophecies. He eventually marries his mother and kills his father as prophesized by the Oracle.
According to Sophocles, fate defines the downfall of Oedipus. He attempts to change the fate in vain. The son of the king has his ankle pierces in a bush in an attempt to avoid the prophecy, but survives to fulfill the prophecy. Oedipus orders Creon to go and discover the fate of Thebes from the temple of Apollo. This marks the unraveling of Oedipus killing his father and marrying his mother. Tiresias, the blind prophet of Apollo reveals the real identity of Oedipus. Oedipus discovers that he is the murderer and he will become blind other than being exiled.
Oedipus talks to Jocosta who elaborates that the Oracle said that he would be killed by his own son. Jocaster says that Oedipus should not worry about the prophecy since both Apollo and Laius made unfulfilled prophecies before. Oedipus begins thinking that he killed Laius and a recount is made on an accusation made by a drunkard during dinner that Oedipus is a coward. Oedipus proceeds to Oracle at Delphi where he hears about his fate. He tries to protect Merope and Polybus by fleeing Corinth in an attempt to escape his destiny. These attempts fail to meet the intentions as the prophecy comes to pass.
When messengers deliver the news that Polybus died a natural death, both Jocasta and Oedipus rejoice. This good news turns sour on proving that the Oracles are wrong. Oedipus still remains fearful of the prophecy of not being able to return to Corinth with Merope alive since he may marry her. The messenger tells him that Merope is not his mother, which brings a twist in his identity. It becomes apparent that no alteration is possible on fate. Oedipus gets ruined while both Laius and Jocasta perish as determined by fate despite attempts of evasion.