A logline is a short description of a movie or television show. It is usually only a sentence in length. The synopsis is used to pitch a movie script or TV show to a studio. A logline should highlight the most interesting aspect of the movie.

A logline should make a producer want to read the script to learn more.

Logline and Tagline Difference

A tagline is not the same as a logline. A tagline is what you see on movie posters. A tagline does not explain the movie enough to be used as a logline.

For example, a tagline used on a movie poster for Scott Pilgrim Vs The World was "An epic of epic epicness." That is entertaining when seen on a movie poster but it does nothing to explain the film. You can see a list of taglines here. Taglines are also generally shorter than a logline.

Help Writing Loglines

Here are some helpful resources offering information about how to write loglines.

• Good and Bad Logline Examples - This PDF paper from the Algonkian Conference lists several example loglines and tells you what is good or bad about it.
  
  
• Ten Tips for Writing Loglines - This article on Raindance offers some clear tips including don't use a character name and describe the protagonist, their goal and the antagonist or antagonist force opposing them.
  
  
• Writing Loglines SlideShare - This ten part slide from Billy Marshall Stoneking says, "If you can't say it one sentence, you don't know what it's about."
  
  
• How to Craft an Effective Logline - This advice article from Final Draft says a longline should be one sentence long. They advise not being too generic and be sure to describe the story, not the theme.
  
  
• How Not to Write a Logline - The advice in this Script articles include a warning not to use cliches.
  
  
• Writing a Killer Logline - Graeme Shimmin explains his logline formula in this helpful article.
  
  
• How to Write a Logline Producers Won't Pass On - This article from Studiobinder explains the logline formula: inciting incident + protagonist + action + antagonist.

Here's a video about how to write a logline from The Script Lab. It uses the Argo logline as an example: