It seems to me that we should not have the first line of this be nearly identical in meaning to the first line of Plot Device. Hence my attempt at a change.

Isn't there a type of Mac Guffin which is more abstract, like a pearl of wisdom, or is that a different thing entirely?

Has anyone yet pointed out that the crystal shard from The Dark Crystal is NOT in ANY WAY a Mac Guffin and shouldn't be included in the example picture? The shard is a piece of the titular crystal - it is vital to the plot, because reuniting it with the crystal saves the freaking world. If it were replaced by any other object in the universe it would, y'know, NOT save the world. Sorry for the tone, but it's pretty irritating to see something which is very obviously not a Mac Guffin half an inch from the description of what makes a Mac Guffin.

On the same note as Mercury, I call "Foul" on identifying the Holy Grail as a Mac Guffin. Since the Big Bad gets the Hero to find and give it to him by shooting his dad, the healing properties of the Grail are essential to the plot.

I'd like to make an edit, but I'm new here. To me, Mac Guffin should be directly linked to Chekhov's Gun as an Antonym. If something is introduced, as a minor detail, it has these two possible paths. Mac Guffin is the "red herring" to a Chekhov Gun. Obviously there is a spectrum between these two tropes, but these are the opposite results: it either becomes incredibly important (gun), or it doesn't, and serves to distract the viewer's attention (Mac guffin).

Just to make this clear- the Nostalgia Chick is NOT using the official trope, but her own version. Fifth Element (I haven't seen Dune) does NOT count as the stones are used at the end and so have a purpose- you CANNOT replace them with a bag of gold.

I see the joke that gave this trope its name, but I dont get it. Could someone explain the punchline?