The inversion of roles is one way the relationship between father and son changes in Wiesel's Night.
At the start of the narrative, there is a clearly defined relationship between Eliezer and his father. Chlomo Wiesel is described as "cultured, rather unsentimental man … more concerned with others than with his own family." He is the authoritarian figure in the family whose word is taken above all. For example, he is direct in how he insists that Eliezer refrains from his studies in Judaic mysticism and focus on more worldly matters. Eliezer recognizes that being the head of the family helped to create an emotional distance between them. As the Nazis strengthen their hold in Sighet, Chlomo's authority extends to the community, as he is a civic leader who assists others in the midst of Nazi cruelty. His positions as head of the family and as a community leader represent a significant part of his early characterization in the narrative.
As Eliezer and his father experience the horror of the campes, an inversion of roles takes place. Over time, Eliezer becomes a "father figure" and Chlomo becomes dependent on him, like a child. For example, Eliezer has to teach his father how to march properly in cadence. He also becomes in charge of both of their food rations, sometimes sacrificing his own so that his father can eat. Eliezer coaches his father through the selections and looks out for him as others take advantage of his weakened state. As Eliezer struggles to survive, he recognizes that he has a responsibility to his father. He acts as a paternalistic force, the way his father once did to him.
The Holocaust robbed children of their childhood, forcing many to grow up far too quickly. Eliezer experiences this in the way he has to tend to his father, putting his own needs second. In this way, the relationship between Eliezer and his father changes over the course of the narrative.