What was the theme of most plays?

Most plays in ancient Greece were tragedies, which means that they ended in catastrophe for the main characters. Tragedies often explored themes of human suffering and the consequences of one's actions. For example, the play Oedipus Rex tells the story of a king who unknowingly kills his father and marries his mother, eventually leading to his downfall. Other common themes in Greek tragedies include the conflict between good and evil, the importance of fate and destiny, and the human desire for power.