From the onset of A Doll's House, the scene is set for the comfortable middle class life that Torvald and Nora enjoy and the audience sees "A room, comfortably and tastefully, but not expensively, furnished." Within the class system of the nineteenth and early twentieth century, women were still marrying for status and men were still expected to be the only breadwinners.
Torvald has received a promotion so can provide for his family without worrying. "It's glorious to feel that one has an assured position and ample means" confirms the status of the family. Nora no longer has to "tire your blessed eyes and your delicate little fingers." The fact that the family can afford a servant reinforces their secure standing. The Helmer children also have a nurse, in keeping with social standings; the same nurse that Nora had as a child. Anna has seen little of her own daughter but there wasn't much she could do at the time as "a poor girl who's been in trouble must take what comes. That wicked man did nothing for me." At least, taking a job as Nora's nursemaid allowed her to manage.
The class system is alluded to when Mrs Linde arrives and Nora can hardly believe that Christina's late husband "left you nothing?" Christina married him because she needed stability and because her mother was ill - "I didn't think it would be right for me to refuse him." Love was not part of the solution. Christina now needs to find office work - "such drudgery," as Nora suggests - because "I have no father to give me the money, Nora." Krogstad will show his bitterness that Christine left him "for the sake of money."
The Helmer family's standing is further referenced by Christine's assertion about Nora who is only apparently concerned with domestic life and "who knows so little of the troubles and burdens of life." This is what prompts Nora to reveal her situation to Christine as long as she never tells Torvald because "how painful and humiliating it would be for Torvald, with his manly self-respect, to know that he owed anything to me." Torvald is very aware that they must maintain appearances so would never tolerate anything that would tarnish his image. This links to the theme of class - hypocritical and more concerned with airs and graces than any real issues; "Of course, Torvald had to live well. And I couldn't let the children go about badly dressed."
Dr Rank suggests that some people only maintain their standing in society by "sniffing around in search of moral rottenness" which allows them to carry on corrupt business practices. Torvald believes that his status in the bank affords him some respect and is horrified that Krogstad - who was his "friend" in college - "calls me by my Christian name."
Appearances and reality combine with the class theme as Torvald tries to hold on to his apparent dignity which Nora now threatens. This will cause the ultimate breakdown of their marriage as the pressure of maintaining his place in society overtakes any rational thought Torvald may have.