Situational Irony- occurs when what happens in the story is the opposite of what is expected to happen.
The Necklace is full of examples of dramatic irony. At the beginning of the story, when Loisel presents her with an invitation to a highly selective ball, Mathilde, who was very fond of finery, rejects the invitation saying, "What do you suppose I am to wear?". Later in the story, she loses a valuable necklace her friend lent her to wear to to the ball. She buys a replica of the necklace she lost, and then has to pay off an enormous debt. She "played her part heroically" in order to pay off the debt of 36,000 francs, doing physical labor, something that she would have never considered herself low enough to do at the beginning of the story. She loses the one thing she had, her beauty, in the process. At the beginning, she was described as "pretty and charming", but after ten years of paying off debt she "looked old". At the end of the story she confronted her friend and learned that the diamond necklace she had worked so hard to pay off was only costume jewelry, worth no more than 500 francs.
Man vs. Self
In The Necklace, Madame Loisel had always thought of herself above everyone else. She was wealthy by most people's standards but to her she was, "as unhappy as though she had married beneath her." "She suffered endlessly , feeling [she was] born for every delicacy and luxury," know to man. When her husband brings home an invitation to a high class ball , that he had worked hard to get, she only thought if herself and decides she doesn't have anything to wear. As the story plays out she ends up going to the ball while wearing borrowed jewels ,that cost way more then she could ever afford. When she loses them, she must work hard labor for the next 10 years to repay the woman she borrowed them from. She later learns that the jewels were only consume jewelry and learns a valuable lesson that things don't have to cost a fortune to look like one.