Mrs. Helene Alving
Mrs. Helene Alving is a smart, capable woman who successfully manages her estate and her husband's legacy. She has built an orphanage to honor his memory, but her public show of devotion is insincere. She presents a picture of a happy marriage and respectable husband to hide Captain Alving's affairs and profligate lifestyle. Although she despised her husband's behavior and its consequences, she accepted that it was her duty to stay with him. The love of her life is her son, whom she tried to shield from his father's past. Her carefully cultivated facade eventually crumbles, as she reveals the truth about her past to her family and friends.
Osvald is Mrs. Helene Alving's only child. He was sent away to Europe when he was seven, because his mother thought Captain Alving's behavior set a bad example for the boy. Osvald became an artist and embraced the more open and progressive society of Paris. He returns home for the opening of the orphanage, still believing his father was an admirable man. However, his illusions about his father are destroyed when he hears the truth about him. He then thinks he understands how he has inherited syphilis, the disease that has already begun to kill him.
Pastor Manders was a childhood friend of Captain Alving and is a trusted adviser to Mrs. Helene Alving. He was also Mrs. Alving's first love. He is the person Mrs. Alving turns to for support in the early days of her marriage, but he turns her away and sends her back to a husband she does not love. Pastor Manders upholds traditional views of morality and duty without always knowing much about the situations he judges so harshly. He is mostly concerned with avoiding scandal and keeping up appearances, even if it makes him a hypocrite.
Engstrand is a long-time acquaintance of the Alvings, who for self-serving purposes agreed to adopt Regina, Captain Alving's illegitimate daughter. He has never loved her as a father, however, and tries to convince her to take up employment in his seaman's hotel (where she would be a prostitute). Engstrand serves as a foil for Pastor Manders, who has equally heinous motives but conceals them behind propriety.
During the play, Regina learns that she is not Engstrand's daughter at all, but the illegitimate daughter of Captain Alving, whose widow she now serves as a maid; with this revelation, she learns that she is half-sister to Osvald, with whom she has begun to fall in love. Barred now from happiness with him, she seemingly has no option but to seek her way as a prostitute in the city.