A problem play focuses on a current social problem in a realistic manner. In Candida, written in the 1890s, Shaw critiques Victorian stereotypes about women, love, and marriage. Women's issues were coming to the forefront in that period, as women became increasingly dissatisfied with their limited role in society, including lack of the right to vote, and increasingly felt restricted by their expected subordination to men and their expected embrace of the role of "angel of the home."
In Candida, Shaw creates a female protagonist who challenges stereotypical ideas about women. Candida is a strong woman who is not so much a loving, nurturing "support" for her clergy husband as an active agent in his success. Another man, Marchbanks, falls in love with her, deciding she is a divine angel that he can worship. Morell, her husband, thinks she needs his guidance and strong, male protection. Candida needs neither worship, nor protection, even though these are the Victorian ideals of what a woman should expect from a man. She is powerful in her own right, and in a rupture with Victorian conventions about love and gender, chooses not the stronger man, but the weaker, Morell, to be her partner.
In sum, this is a problem play because Shaw shows that conventional Victorian ideas about women are wrong and should be challenged.
A problem play is a play in the tradition of realism dealing with a problem--social, moral, political, philosophical and so on. The Norwegian dramatist Henrik Ibsen pioneered this kind of drama in Europe, and Bernard Shaw in England followed suit.
'Candida' is a typical Shavian problem play that handles the problem of love and marriage, and of man-woman relationship. The arrival of the young poet, Eugene Marchbanks, at the house of the socialist clergyman, James Mavor Morell, and his long-married wife, Candida, catapults their happy married life, as the middle-aged Candida discovers herself strangely caught in between her dependent husband and her independent lover. Morell feels increasingly scared of being dispossessed of his wife's loving support without which he just cannot survive as a preacher and a social reformist. He gets apprehensive of a 'calf-love' between his wife and the young poet. Marchbanks, on the other hand, tells Candida of love-romance-imagination beyond the limits of domesticity and expediency. The triangular love-situation, an age-old motif in literature, however reaches its culmination in the 'auction scene' where Candida puts herself to auction, and chooses 'the weaker of the two', i.e. her husband Morell. Marchbanks leaves to dissolve into the darkness of the night, carrying the 'mystery' in his poet's heart.
Shaw chooses an apparently stereotypical love-triangle, in which a married woman falls in an extra-marital affair. But he charateristically turns the table as the woman is neither driven out by her husband, nor does she elope with her unlawful lover. Candida stays back with Morell because he is weaker than Marchbanks, and Morell desperately needs her. Morell is no longer the strong and self-important husband. It is rather Candida who is in full command of the emotional as well as social-economic situation.