Jason Momoa is Perfect as Duncan Idaho in ‘Dune’

One of the great thrills of watching Dune is seeing an all-star cast tear into the iconic characters of Frank Herbert’s novel. Timothée Chalamet has Paul Atreides’s dark hair, handsome face, and boyishness. Rebecca Ferguson plays Lady Jessica with all the grace and danger of any great Bene Gesserit sister. Oscar Isaac, Zendaya, Javier Bardem, Josh Brolin…they all bring the roles of Duke Leto, Chani, Stilgar, and Gurney Halleck to fully-realized life. However there’s one casting choice in Dune that trumps them all and that’s Jason Momoa as the stalwart, swashbuckling Duncan Idaho.

Duncan Idaho is a role that filmmakers often don’t know how to handle as his cool factor exists in the margins, sequels, and appendixes of Dune. His influence on Paul and all of House Atreides is immeasurable, even if his heroism often happens “off-screen” in the book. While other adaptations have struggled to explain Duncan’s hold on Paul’s imagination, director Denis Villeneuve did it simply by casting Jason Momoa.

Dune takes place in a far future where humanity has rejected computers and artificial intelligence in favor of religious fervor and mind-bending psychedelics. Young Paul Atreides is the son of a popular Duke and therefore lives with the burden of knowing one day he will be expected to follow in his father’s footsteps as a political leader. However Paul also has pressure from his Bene Gesserit mother, Lady Jessica, to be a potential messianic figure known as the Kwisatz Hadderach. Seemingly the only mentor in Paul’s life who is also a real friend is the roguish Duncan Idaho.

Duncan Idaho is first introduced in Frank Herbert’s Dune… Well, he’s introduced by his absence. Paul wants to know where Duncan is and learns he has led the advance forces on Arrakis. Later, we learn that Duke Leto sent the charismatic warrior ahead to make diplomatic contact with the Fremen, Arrakis’s native population. When Duncan returns, he brings along Stilgar, the leader of the Fremen tribe, and a deep mistrust of Lady Jessica. Nevertheless, Duncan is defined by his loyalty to House Atreides and his willingness to lay down his life for them. So much so, later books introduce a clone version of Duncan, known as a gholem, who protects and even falls in love with later family members.

The tricky thing about Duncan Idaho in the first Dune book is he’s barely in it, but treated like one of the great formative presences in Paul’s life. How to reconcile that on screen? Villeneuve beefed up the supporting role’s screentime and cast one of the most likable onscreen presences working today, Jason Momoa.

Since his breakthrough turn in Season 1 of Game of Thrones, Jason Momoa has gleefully built a career on playing an archetype I’d call the “Warm Warrior.” He favors action-packed stories about tribal leaders, whether that’s Netflix’s Colony, Apple TV+’s See, or Aquaman. More often than not, Momoa plays a badass. A masculine hero who can punch, cut, and spear his way out of any danger. The twist is Momoa’s characters usually fight for love of family, friends, or the greater good. There is a softness in all of Momoa’s roles that belies his own intimidating frame.

Villeneuve takes full advantage of this, giving Momoa the best hand-to-hand combat scenes in the film and by letting the actor engulf Chalamet in multiple bear hugs. Jason Momoa plays Duncan Idaho as the ideal knight: noble, loyal, fierce, and soft-hearted. That’s how Paul sees him and that’s how the audience sees Duncan from the jump. After all, Jason Momoa is playing him!

By casting a star of Jason Momoa’s stature in the supporting role of Duncan Idaho, Villeneuve was able to convey the character’s importance to the audience without any need for exposition. We just felt instinctively how important Duncan was for Paul. He was the friend, mentor, brother, and idol the young noble needed. We understood that because that’s the kind of role Jason Momoa always plays: the warrior with a heart of gold.

Where to stream Dune