The Maltese Falcon. The plans for the Death Star. The money in Pulp Fiction and Psycho. The Ark of the Covenant, sought by Nazis and Indiana Jones.
These are MacGuffins: an object or a character in your story that everyone wants. It initiates the plot, keeps the action moving, and ultimately has very little significance to the story.
In a post on Writers in the Storm, Eldred Bird ID’s a few MacGuffins and explains how they’re used. In the first Harry Potter novel, everyone is searching for the Philosopher’s Stone, but ultimately, we never see it used. A MacGuffin can also be a person, such as Private Ryan in Saving Private Ryan. While the effort to rescue Ryan from the battlefront is the key driver of the story, the private isn’t the protagonist and doesn’t even appear for the majority of the film.
“While people mainly associate MacGuffins with mysteries, they are a useful tool in any genre,” Bird says. “They can be anything from a lost love that haunts the protagonist throughout a romance, to the search for a rare record album that leads to a character’s ultimate redemption. Just remember that the specific object is never as important as the actions and reactions it creates.”