Ma and Jack as characters in a book (Dramatic Irony)
When Ma compares her and Jack's captivity to being characters trapped in a book that only Old Nick can read, there is deep and obvious dramatic irony in the fact that, unbeknownst to Ma, she and Jack literally are characters within a book.
Sunday "treat" (Situational and Verbal Irony)
In order to survive, Old Nick provides Ma and Jack with essentials: food, electricity, minimal furniture, and plumbing. For anything extra they require, Ma has to put in a request for a "Sunday treat." In the novel, Ma has to ask for a new pair of jeans for Jack as a Sunday treat, and even these are cheaply made. The most obvious irony here is in the name. Ordinarily, a "treat" is a relatively rare event or object that provides a great deal of happiness. Instead, Ma has to use this phrase to request what a first-world society would consider basic necessities, such as clothing. This presents the twisted mindset of Old Nick, who believes that Ma and Jack are somehow indebted to him for his generous "Sunday treats." It is therefore extremely ironic that these Sunday treats are used as a way of Old Nick appearing to be generous towards them, when, in reality, he has stolen seven years of Ma’s life by imprisoning her.
The television interview (Situational Irony)
When Ma and Jack escape Room, they are bombarded with media attention. Ma agrees to do a television interview to ensure she is not misrepresented in the media. During the interview, the focus shifts from her time in Room to the discovery that she still breastfeeds Jack at the age of five. Ironically, the interviewer is most shocked and inquisitive about this fact, not Old Nick’s heinous crimes. This is an irony that Ma quickly identifies and confronts the interviewer about. It especially highlights the difference between sympathy and scandal: the media is hungry to hear about such a terrible incident, but they are less attuned to accepting that Ma had to breastfeed Jack. It is almost as if their seven-year-long imprisonment is accepted as terrible precisely because it is so outside the realm of everyday life; yet, on the other hand, when an activity that fits into everyday life is compromised, there is outrage.
Jack being "dead" (Dramatic Irony)
There is fantastic dramatic irony in the scene were Ma is pretending that Jack is dead. We, the reader, know he is not, and we can hear his thoughts. However, we can also hear Old Nick's questions through Jack; as far as Old Nick knows, Jack is dead, and he is therefore faced with a quandary. This is classic dramatic irony, for the reader knows something one of the characters most assuredly does not.
