Abba is a middle-aged accountant living in San Francisco, working steadily at his firm since the Eisenhower administration. He is highly disciplined, frugal, and dresses formally, favoring a neutral suit and Oxford brogues. Despite his outward conformity to corporate life, he harbors a quiet daydream of teaching music history at a small college.

Eugene is Abba's childhood friend who skips college to work in an auto-parts dealership before building a highly profitable business. Known for his casual demeanor and ever-present baseball cap, he possesses a natural charisma and social instinct. He easily attracts success and valuable connections without the anxious striving that defines Abba's life.

William is the younger, more conventional son in a family dealing with rapid social changes in the early 1970s. He possesses ordinary abilities compared to his sibling but actively tries to bond with his parents, particularly his father. He frequently feels outshone and looks for ways to distinguish himself and secure his position as the favored child.

Clive is an eccentric mathematical genius who distances himself from his family's expectations by speaking Hungarian and acting aloof. He receives special treatment from his parents, who are both proud of his brilliance and anxious about his differences. He spends his time smoking marijuana with his best friend and keeping his girlfriend hidden in the family basement.

Wilson is a 54-year-old baseball enthusiast trying to manage life after his wife leaves him. He hides his loneliness by wearing trendy clothes, making brash jokes, and frequenting local bars. He desperately misses the traditional family structure he once had and relies on the Boston Red Sox as his main connection to happier days.

Brent is Wilson's 20-year-old son, a serious and sensitive college student who spends his summers volunteering at homeless and women's shelters. He wears an earring and comfortably discusses social issues, standing in sharp contrast to his father's traditional masculinity. He recognizes his father's emotional struggles and takes an active role in trying to pull him out of his depression.

Mr. Hundert is a dedicated history teacher at the elite St. Benedict's boarding school for boys. He views his profession as a solemn duty to mold unruly boys into men of classical character and moral fortitude. Despite his strict adherence to rules and tradition, he possesses an unspoken fascination with the wealth and power of his students' families.

Sedgewick is the privileged, imposing son of a populist United States senator. As a student at St. Benedict's, he relies on his physical stature and natural charisma to avoid academic work, preferring to gain popularity by defying authority. He quickly learns to use his family's influence to insulate himself from the consequences of his actions.

Simon is Clive and William's father, a former World War II marine who works as an insurance provider. Anxious about keeping up with changing cultural tides, he trades his conservative Jewish faith for pacifist Quakerism and adopts 1970s fashions. He struggles to understand his eccentric oldest son while projecting an image of modern, progressive fatherhood.

Scheherazade is Abba Roth's wife, a woman defined by her capricious nature and expensive tastes. She frequently spends Abba's accounting salary on extravagant home decorations and personal adornments like Persian carpets. Her impulsive emotionality contrasts sharply with her husband's calculating, formal demeanor.

Naomi is Abba Roth's brooding, spendthrift daughter. Despite her frequent demonstrations of distance and lack of affection toward her father, she remains his clear favorite among his children. She inherits much of her mother's tendency toward financial extravagance.

Sandra is an attractive young woman introduced to the family as Clive's girlfriend. She takes up residence in the family's basement, where she smokes marijuana and spends time with Clive and his friend Elliot. She eventually develops a flirtatious and physically intimate dynamic with Clive's younger brother, William.

Elliot is Clive's closest companion, frequently joining him in the basement to smoke weed and converse in Hungarian. He shares Clive's outsider status and serves as his primary confidant away from the pressures of the family.

Margaret is an intelligent, inquisitive woman whom Brent invites to dinner after meeting her at a baseball game. She displays a natural conversational ingenuity and a strong ability to ask engaging questions. She begins dating Wilson after dinner, offering him a chance at a new connection, though he frequently compares her to his former wife.

Abbie is Wilson's ex-wife and Brent's mother. She leaves Wilson for a vice president at his firm, an event that shatters Wilson's sense of stability and plunges him into a deep depression. Her absence looms large over Wilson's attempts to manage his post-divorce life.

Deepak is a highly conscientious and studious pupil at St. Benedict's. He possesses a genuine talent for Roman history and answers academic questions without hesitation. He represents the ideal, rule-abiding student who earns his achievements through merit rather than family influence.

The senator is a powerful, populist politician and a demanding father. He uses his massive influence and intimidating presence to manipulate the faculty at St. Benedict's, famously instructing Mr. Hundert that he expects the school merely to teach his son, while he will mold him.

Charles is a fellow educator at St. Benedict's who initially shares Mr. Hundert's commitment to classical education. Their professional camaraderie shifts as they both eye higher administrative positions within the changing environment of the school.