What is a MacGuffin? In short: it's the reason you're watching the movie.
That's it right? Well... it's a little more nuanced than that. It's a plot device that helps drive the narrative forward but really isn't that important ultimately to the story.
It's a great concept that helps you accomplish your story goals in a compelling manner.
We're going to provide over 10 examples that will help you understand just how influential and varied this all-important device really is.
What is a MacGuffin To The Man Who Popularized The Concept
"...the thing that the characters on the screen worry about but the audience doesn't care about."
Originally coined by Alfred Hitchcock, this concept is one of those things that's easy to spot but difficult to explain—like, say, the Nickelback fandom.
Most understand it as an important element that serves the story in some capacity, but apart from that, their definition gets a little hazy, but this video essay by ScreenPrism demystifies the Hitchcockian concept once and for all, and even offers George Lucas' alternative meaning for the term for comparison.
Here is how Hitchcock himself put it:
[A man] says, "Well, what is a MacGuffin?" You say, "It's an apparatus for trapping lions in the Scottish highlands." Man says, "But there are no lions in the Scottish highlands." Then you say, "Then that's no MacGuffin."
Lotsa help there, Hitch...
He does give a pretty good explanation when he describes it as "the thing that the characters on the screen worry about but the audience doesn't care about."
So, it is a plot device that acts as a catalyst to drive some of the action in the story.
A couple of great examples are the stolen money that motivates all of Marion Crane's actions in Psycho, or the Heart of the Ocean in Titanic. These are known as "pure MacGuffins" because they follow Hitchcock's strict criteria: they must be incredibly important to the characters, but quite vague and meaningless to the story itself.
However, George Lucas' interpretation of the plot device is slightly different.
How About A Different Definition?
To Lucas, it is still an object/prop that acts as a plot device, but it's just as important to the audience as it is to the characters. Things like the ring in The Lord of the Rings, the Horcruxes in the Harry Potter series, and the Ark of the Covenant in Raiders of the Lost Ark are great examples of Lucas' version.
A kind of a classic example of one might a briefcase. Just an object, or prop, that has a secret in it or that people are after. But thinking of it as a prop might help you in relation to your art department.
Many times new filmmakers won't be as intentional as they could be with the objects that appear on screen, but props can be used in so many pivotal ways, whether to bring some realism to your scene or add some nuance to your character.
More Examples from Hitchcock
In Notorious, the MacGuffin is uranium ore stored in wine bottles.
Vertigo has the necklace.
Rear Window has a suspected murder committed across the courtyard.
The Lady Vanishes has a coded message in a piece of music.
In Dial M For Murder it's a spare apartment key.
Notice how in some of these instances it is something you could watch the movie and not even remember. While in other instances, like Rear Window, it looms large over every single scene.
Either way can be effective so long as the plot device is driving the narrative forward.
More Famous Examples
Almost every movie has a MacGuffin of some sort. The movie The Founder about the story behind McDonald's even had some Egg McGuffins.
That was so bad. Just couldn't help it.
Ok here are some more unforgettable examples:
The Maltese Falcon has the Maltese Falcon itself.
Citizen Kane has one of history's most unforgettable ones: Rosebud. The word, uttered by a dying magnate, becomes a source of fascination for one reporter. Along the way, he learns other things, but never what Kane meant by the word.
We learn though.
Pulp Fiction has a shining case. A lot of movies use a mysterious briefcase, as previously mentioned.
Star Trek 2: The Wrath of Khan has the genesis device. A strange all-powerful tool to create life, which becomes a great metaphor when the movie's main theme is aging and death.
Star Wars has, of course, the death star plans. Interestingly enough, that one was so 'epic' that it got a spinoff movie, Rogue One.
When Macguffins are characters
Yes, they can characters. Let's start off with how the Star Wars franchise does this.
There is an interesting case to be made that The Empire Strikes Back has Darth Vader as its protagonist, with Luke Skywalker himself as the all-consuming plot device.
In either case, the sequel The Force Awakens certainly turns the Luke character into a traditional example.
The Hangover has the groom, who they lost in the night they can't remember. People loved the Hangover, but the genius behind its success is having such a clever and creative plot device.
It's a great example because the entire plot, and all the comical situations, arising out of that simple set up. We went out partying and we lose the groom.
Private Ryan fits the bill in Saving Private Ryan. And the characters we follow aren't too thrilled about it either.
Colonel Kurtz does it in Apocalypse Now. Can you really have a better one than Marlon Brando?
Now that you know what this thing is (and that it isn't a McGuffin), be sure to tell everybody who asks you about it the whole "trapping lions in the Scottish highlands" thing," because life isn't fair.
But what you can really do with this knowledge is use a creative plot device idea to launch your next script. Once you have a fun one in mind you might be ready to start putting together a treatment.
When you really think about it, this could be the most important single element to your story. Without it, there isn't much of a plot.