The Dude (Played by Jeff Bridges) is...well he's an excellent character, man. Ever since he first appeared back in 1998's The Big Lebowski, he has become a stable of cool in pop culture. And to create such a legendary character took a lot of inspirations. For the most part, he was inspired by American film producer and political activist Jeff Dowd, who the Coens met while they were trying to find distribution for their first feature, 1984's Blood Simple. Dowd, a member of the anti-Vietnam War movement Seattle Seven, liked to drink White Russians, and was known as "The Dude". He wasn't the only one with that moniker to inspire Bridges character either. Filmmaker John Milius, who the Coens met while they were in Los Angeles making their 1991 film Barton Fink, introduced the Coen Brothers to one of his best friends, Jim Ganzer who had a gang of typical surfers and was also know as "The Dude".
The last major inspiration was that of Peter Exline. A friend of the Coens, Exline was a Vietnam War veteran who reportedly lived in a dump of an apartment and was proud of a little rug that "tied the room together". Exline was initially introduced to the Coens back when the brothers were trying to raise money for Blood Simple by filmmaker Barry Sonnenfeld (Who Exline knew from New York University) and Sonnenfeld introduced Exline to the Coen brothers while they were trying to raise money for Blood Simple. After becoming friends with the Coens, in 1989 Exline told them all kinds of stories from his own life, including ones about his actor-writer friend Lewis Abernathy (Who became an inspiration for the character of Walter). Abernathy was a fellow Vietnam vet like Exline who later became a private investigator and helped Exline track down and confront a high school kid who stole his car. As in the film, Exline's car was impounded by the Los Angeles Police Department and Abernathy found an 8th grader's homework under the passenger seat. Exline also belonged to an amateur softball league but the Coens changed it to bowling in the film, because, in their words, "it's a very social sport where you can sit around and drink and smoke while engaging in inane conversation".
And with all that, the Coens created a character that danced his way into the hearts of cinema fans. Or bowled his way in. Who knows? You choose whichever metaphor works for you. After all...