In the opening sequence of David Lynch’s 1984 Dune adaptation, Princess Irulan (Virginia Madsen) explains the importance of the spice, and why it is the most precious substance in the universe.

Spice is the most valuable resource in the Dune Universe, and it's crucial to the plot of the movies. Here's what we know and why it matters.

You could wear blue-colored contacts, or — if you happen to be a character in "Dune," the movies based on Frank Herbert's sci-fi books — you could ingest some spice. They'd have the same ...