Jeff Lebowski, known to all as "The Dude," is an easygoing slacker whose daily life revolves around bowling and a carefree existence in early '90s Los Angeles. His casual routine is abruptly disrupted when two thugs mistakenly break into his apartment, demanding money owed by a man with the same name. This case of mistaken identity launches The Dude into an increasingly complex and bizarre set of circumstances involving the other, wealthier Jeff Lebowski—whose trophy wife owes money to known criminals. The situation escalates when The Dude is offered a job by the millionaire Lebowski: to deliver the ransom for his wife's purported kidnapping. The Dude accepts, hoping for a simple transaction and a quick payoff.

Enlisting the help of his bowling buddies, hot-tempered Vietnam vet Walter and the mild-mannered Donny, The Dude embarks on the task but quickly finds himself out of his depth. Walter's impulsive antics lead to a disastrous exchange that fails to resolve the situation. As The Dude seeks to understand the true motives behind the kidnapping, he encounters a range of eccentric characters, including a radical feminist artist, nihilist thugs, and a smooth-talking pornographer. The Dude's quest to sort out the tangled web of lies and deceit draws him deeper into the underbelly of Los Angeles, causing constant misadventures that begin to reflect the absurdity and unpredictability of life itself.