Adam Merkin, a graduate student at Berkeley, is deeply engrossed in writing his thesis on the contentious use of the word "nigga" within the realm of battle rap. In pursuit of knowledge, he attends an exhilarating rap battle featuring renowned rappers X-Tract and Behn Grym, bringing his girlfriend, Maya, along for support. However, Maya is taken aback by what she perceives as the rampant sexism prevalent in the lyrics. Adam tries to interview Grym but soon finds himself the subject of ridicule for his academic approach.
In a surprising turn of events, Adam intervenes in a confrontation initiated by a young white rapper named Billy Pistolz, delivering a compelling freestyle that denounces cultural appropriation. Grym, impressed by Adam's boldness, agrees to have a deeper conversation with him. Meanwhile, Adam's father, Professor Merkin, a best-selling author, dismisses his thesis idea, further fueling Adam's determination to succeed.
Responding to a challenge from battle promoter Donnie Narco, Adam steps into the ring for a newcomer battle against Korean rapper Prospek. Although initially met with unenthusiastic responses to his joke lines, he shifts gears and resorts to humor regarding Asian culture, ultimately winning over the crowd and claiming his first victory. Along the way, Adam meets fellow competitors such as Che Corleone, Devine Wright, and the menacing Megaton, known for his fierce bravado.
In a challenging moment during dinner at a vegan restaurant, Adam tries to justify his intentions to Maya regarding his continued involvement in battle rap, but his comments backfire, leading to an intense argument and his subsequent eviction from the establishment. The strain on their relationship escalates as Adam unwittingly offends Maya and ultimately loses her after a run-in with his rapper friends.
After a hard-fought evening where Adam, Che, Devine, and Grym emerge victorious in their matches, they celebrate at a party hosted by Megaton. However, tensions rise when Che's entanglement with Megaton's girlfriend, Bella Backwoods, triggers a feud, resulting in an anticipated battle between the two.
Adam seeks solace with Behn Grym, who—beyond his rap persona—harbors a secret life as a video game designer and a father to a child suffering from cystic fibrosis. Grym emphasizes his desire for privacy to avoid personal attacks in battle rap, offering Adam temporary shelter at his home, but is met with resistance from his wife, accusing Adam of cultural appropriation.
Opportunity knocks when another promoter offers Adam a lucrative chance to battle Grym for $5,000 at an upcoming event. Initially overwhelmed by the consequences of his choices, Adam declines, asserting that battle rap has disrupted his life. Unfortunately, Maya takes matters into her own hands, using footage of Adam's battle against Prospek to bolster her thesis, which results in widespread backlash against him from the Berkeley student body. Adam faces the ultimate betrayal, losing his father's support and facing scholarship suspension from the dean.
Desperate, Adam ultimately reconsiders and accepts the challenge to face Grym. During the electric battle, Grym impresses with cunning, fabricated bars, while Adam employs unforgiving personal information about Grym, revealing the struggles with his daughter's health to secure victory. Tensions boil over when Adam confronts opposing rappers for disrupting his flow, resulting in an electrifying two-on-two battle that he and Grym deliver spontaneously.
Following the battle, Grym expresses his discontent, stating that while battle rap tends to be a performance for others, Adam's approach has turned into a disturbing expression of his underlying cruelty. Grym departs, seeking refuge with his family. Heartbroken, Adam reaches out to Maya with a marriage proposal in an attempt to mend their relationship, only to be met with her scornful rejection.
Meanwhile, as Megaton claims glory over Che in their battle, humiliating him with brutal taunts, Adam's frustrations culminate in him stepping up to challenge Megaton. Despite taking a hit that knocks out a tooth, Adam rallies his determination, confronting Megaton for masking his lack of substance with bravado. In a dramatic turn, Megaton concedes to a resilient and triumphant Adam. As Adam settles into a bleak night on a park bench, he stumbles upon a video showcasing his newfound fame, prompting him to contemplate a bold choice for his rap alias.
