Stan is an elementary school student who commonly has extraordinary experiences not typical of conventional small-town life in his fictional hometown of South Park, Colorado. Stan is generally depicted as kind-hearted, intelligent, trustworthy and patient. He is outspoken in expressing his distinct lack of esteem for adults and their influences, as adult South Park residents rarely make use of their critical faculties.
Like the other South Park characters, Stan is animated by computer in a way to emulate the show's original method of cutout animation. He also appears in the full-length feature film South Park: Bigger, Longer & Uncut (1999), as well as South Park-related media and merchandise. While Parker and Stone portray Stan as having common childlike tendencies, his dialogue is often intended to reflect stances and views on more adult-oriented issues and has been frequently cited in numerous publications by experts in the fields of politics, religion, popular culture and philosophy.
Stan lives in South Park at 2001 Bonanza Street with his parents Randy and Sharon Marsh. Randy is a geologist, and Sharon is a secretary at a rhinoplasty clinic. Stan's family includes his 13-year-old sister Shelly, who bullies and beats him, and his centenarian grandfather, Marvin, who calls Stan "Billy" and who previously begged Stan to help him commit suicide. Stan attends South Park Elementary as part of Mr. Garrison's fourth grade class. During the show's first 58 episodes (1997 through the season 4 episode "4th Grade" in 2000), Stan and the other main child characters were in the third grade. His birthday is listed as October 19 (the same day as co-creator Trey Parker), 2001 on his Facebook page during the season 14 episode "You Have 0 Friends". Stan is frequently embarrassed and/or annoyed by his father's antics and frequent acts of public drunkenness. Stan's relationship as nephew to his uncle Jimbo received moderate attention in the show's first two seasons.
Amongst the show's main characters, Kyle is defined as being the only Jewish kid, Cartman is recognized by his obesity, greed, and bigotry, and Kenny is known for being poor and frequently dying. Stan is portrayed as "a normal, average, American, mixed-up kid".
Stan is modeled after Parker, while Kyle is modeled after Stone. Stan and Kyle are best friends, and their relationship, which is intended to reflect the real-life friendship between Parker and Stone, is a common topic throughout the series. The two do have their disagreements, but always reconcile without any long-term damage to their friendship. As is the case with his other friends and classmates, Stan is frequently at odds with Cartman, resenting Cartman's behavior and openly mocking his weight. Stan also shares a close friendship with Kenny, while Kenny professes that Stan is one of "the best friends a guy could have". Stan can understand Kenny's muffled voice perfectly, and typically exclaims the catchphrase "Oh my God! They killed Kenny!", following one of Kenny's trademark deaths, allowing Kyle to follow up with "You bastards!" Stan is the only character in the group to have had a steady girlfriend, Wendy Testaburger, and their relationship was a recurring topic in the show's earlier seasons. Despite reconciling and declaring to be a couple again in the season 11 (2007) episode "The List" after Wendy had dumped him in the season seven (2003) episode "Raisins", their relationship has received relatively less focus in recent seasons. As a running gag, a nervous Stan often vomits whenever Wendy approaches to kiss or speak to him. In many episodes, Stan contemplates ethics in beliefs, moral dilemmas, and contentious issues, and will often reflect on the lessons he has attained with a speech that often begins with "You know, I learned something today...".