What is the term for excessive pride or arrogance that leads to the downfall of a protagonist in a tragedy?

The correct term for excessive pride or arrogance that leads to the downfall of a protagonist in a tragedy is "hubris." This concept is significant in literature, particularly in Greek tragedy, where it often serves as a critical flaw in the character of the tragic hero. Hubris typically involves an overestimation of one's own abilities or a blatant disregard for the gods or moral laws, which ultimately sets the stage for their inevitable downfall.

In contrast, while "pride" might evoke a similar notion, it does not carry the specific connotation of an inherent flaw that results in catastrophic failure associated with hubris. "Agon" refers to a struggle or contest, particularly in a dramatic sense, and does not relate to character traits or flaws. "Egoism" speaks to a self-centered perspective and may imply a sense of superiority, but it does not encompass the pivotal role of hubris in the structure of tragedy and the consequences that follow. Thus, hubris is the term that best captures the essence of excessive pride leading to a protagonist's downfall.