Nils Krogstad is one of the secondary characters in the play, but important nonetheless. He holds a position subordinate to that of Helmer in the Bank and is initially portrayed as an unscrupulous, dishonest, and unsympathetic man.
Even before his entry into the play, he is painted as a typical villain, cruel, and devoid of morals. According to Dr.Rank, he is “rotten to the core.” Helmer, on several occasions, expresses his disapproval of Krogstad’s character, calling him “a man without scruples.” He believes that an atmosphere of lies, like that of Krogstad’s house, “infects and poisons the whole life of a home.” Helmer also remarks that Krogstad will make his position in the Bank “quite intolerable.”
Krogstad has a criminal record of having committed forgery, and is thus extremely protective about his position in the bank, as he finds it extremely important to hold a respectable position in the bank in order to redeem himself.
When he finds out that his position in the bank is in jeopardy, he holds Nora responsible for it and starts blackmailing her. His position in the bank is extremely dear to him, which is evident by his words, ”I shall fight to protect my little post at the bank as I’d fight for my life.”
He also tells Nora, “My sons are growing up, and in fairness, to them, I must try to win back as much respect as I can in the town.” As a last resort, he sends a letter to Helmer revealing to him the secret about Nora’s crimes. However, one may feel sympathetic towards this character, as his only intention behind holding his position in the bank is to be a better role model to his sons.
It is thus seen that Krogstad is actually quite practical and mature, and not as crooked or dishonest as he is portrayed to be.
An important aspect of Krogstad’s character is his redemption after reuniting with Mrs. Linde. He has earlier been in a relationship with Christine, who breaks it off to marry a richer man out of desperation and necessity.
Mrs. Linde decides to try and convince Krogstad to marry him, and in his conversation with her, one sees the emotional side of Krogstad. He expresses his despair on losing Christine, by saying, “When I lost you, it was just as if the very ground had given way under my feet.” He is overjoyed at the prospect of starting a new life with Christine, and almost immediately accepts his proposal.
He says “Thank you Christine. Now I shall be able to set myself right in the eyes of the world too.” Consequently, Krogstad writes a letter to Helmer taking back his threat, and apologizes for it.
Thus Krogstad is a highly misunderstood character, scorned by most of the other characters in a play, but who is actually an ordinary human being in a desperate situation.
Krogstad’s role in the play is that of a catalyst in bringing about the transformation of Nora, as it is his letter and Helmer’s reaction to it that brings her down to earth and makes her realize the true nature of her husband.