World's Greatest Dad

Lance Clayton (Robin Williams) is a single father, unpublished author, and high-school English teacher who dreams of becoming a famous writer. He narrates that he will quit writing if his next book fails and that he is scared of being alone. He unsuccessfully tries to bond with his 15 year old underachieving, manipulative, hostile, sex-obsessed teenage son Kyle (Sabara).[4] Kyle is a student at the school where Lance teaches an unpopular poetry class. His only friend is Andrew, a fellow student who spends his evenings at the Claytons' house trying to avoid his embarrassing alcoholic mother. He is respectful and starkly different from Kyle. Kyle's consistently poor academic performance and vile behavior gain the attention of the school principal, who advises Lance that Kyle should transfer to a special-needs school. Lance meanwhile is in a noncommital relationship with a fellow teacher named Claire, who is spending time with a fellow teacher named Mike who runs a more successful class than Lance. On nights when Claire cancels their dates and he is all alone, Lance bonds with his elderly neighbor.

One night, after Kyle and Lance spend an evening with Claire, Lance discovers in horror that Kyle has accidentally strangled himself in an autoerotic asphyxiation accident in his bedroom, looking at a picture of Claire's underwear that he snuck under the table with his cell phone that night. To avoid embarrassing his son and himself, he stages Kyle’s death as an intentional suicide. He writes a suicide note on Kyle’s computer and hangs his son’s body in the closet. Initially, most of the students and faculty at Lance's school are uninterested in Kyle's death, Kyle having been a very unpopular and unlikeable person. However, a classmate later obtains the suicide note from police records and publishes it in the school newspaper. The note strikes a chord with the students and faculty, and suddenly many students claim to have been friends with Kyle and are touched by how deep and intelligent he shows himself to be in his writings.

Enjoying the attention his writing is finally receiving, Lance decides to write and publish a phony journal that was supposedly written by his son before his suicide. Kyle becomes something of a post-mortem cult phenomenon at the school, and soon Lance begins to receive the attention and adoration that he had always desired. He begins spending more time with Claire, his class becomes more popular, and students treat him as a friend. Andrew finds Kyle’s suicide note and journals as highly uncharacteristic based on Kyle's personality when he was alive, but Lance brushes him off when Andrew confronts him. The journal soon attracts the attention of book publishers and Lance lands a television appearance on a nationally broadcast talk show. The school principal then decides to rename the school library in Kyle’s honor, despite Kyle's attitude at school during his lifetime and the fact that the principal had at one point suggested that Kyle be transferred. Lance's work, though published under false pretenses, earns him all the fame and appreciation he has dreamed of.

At the library dedication, pressed by a combination of his guilt over exploiting his son’s death, his mounting hatred for the hypocrites who claimed false friendship, and the faculty’s new-found admiration of the “genius” of his dead son, Lance confesses before the school. He declares none of them liked Kyle, but that he loved his son, even though he was unpleasant and unintelligent, and that Lance wrote his suicide note and journal to cover up his son's accidental death. Claire slaps Lance and approaches Mike, the principal and students glare and sneer at him, but Lance feels reborn having realized that being alone is not the worst thing. Lance becomes the new social pariah and is hated by everyone, but Andrew tells him he knew Lance wrote the journal and that he enjoyed it and feels Lance should keep writing.