[Editor’s note: The following contains some mildspoilersforDune.]

It’s officially time to get excited forDune, the sci-fi epic directed byDenis Villeneuveand adapted fromFrank Herbert’s 1965 novel of the same name. This is the second timeDunehas made its way to the big screen, in addition toDavid Lynch’s 1984 adaptation. As such, there’s a good chance older fans ofDunewill be familiar with the characters of this unusual world.

dune-paul-atreides-knife-salute

But, if you’re new to or curious about the world ofDuneand the vast number of characters which populate it, it’s worth getting at least the (mildly spoilery!) basics so that you know what the heck is going on if you choose to see it in theaters. You may knowOscar IsaacfromJason Momoa, but do you know Paul Atreides from the Bene Gesserit? Do you know what a Mentat is? Could you list off the names of folks associated with House Atreides and House Harkonnen?

We’ve put together a basic but comprehensive guide on all of the keyDunecast members and an explainer of who they play as well as their role in the story. If you’re new to the world ofDuneor you’re looking to get a refresher, keep reading and get yourself familiarized before this sci-fi space epic hits theaters at the end of the year.

dune-timothee-chalamet-paul-atreides

Dunearrives in theaters on December 18. For more, check outour full trailer breakdownand explanations ofwhat’s in that pain boxandwhat that sandworm is.

Timothée Chalamet as Paul Atreides

Timothée ChalametisDune’s protagonist Paul Atreides, son of Duke Leto (Isaac) and Lady Jessica (Ferguson). It is Paul’s destiny to transform from a well-trained, highly-intelligent, noble-born son to the Messianic figure known as the “Muad’Dib.”

Paul grows up on the sea planet Caladan, where he receives training in the ways of highly analytical thinking, the Bene Gesserit (more on that below), as well as combat, espionage, the sciences, the arts, and more. Paul was trained as such in hopes he would become a Mentat (essentially, a person with a mind more powerful and insightful than a computer or AI program, thus eliminating the need for these things) as part of Leto’s efforts to have as powerful an heir as possible. However, because Paul was born a male (rather than a female, as the Bene Gesserit order had foretold), he, through the powers of his mother, is destined to become one of the most powerful figures inDune: A super-being referred to as the “Kwisatz Haderach.”

dune-oscar-isaac-duke-leto

Oscar Isaac as Duke Leto Atreides

Oscar Isaacis the noble Duke Leto Atreides I, partner to Lady Jessica (Ferguson) and father of Paul (Chalamet). At the start ofDune, Leto is the ruler of the sea planet Caladan and he makes his home there with Lady Jessica and Paul as well as their closest allies and advisors. Leto’s life takes a turn when the Landsraad, the collection of noble houses ruled over by a high council and overseen by a person known as the Padishah Emperor, gives him the planet Arrakis to rule over. This leads to the entirety of House Atreides — Leto and his family, his advisors, and his army — moving from Caladan to the desert planet.

Rebecca Ferguson as Lady Jessica

Jessica Fergusonis Lady Jessica, a member of the Bene Gesserit, the concubine of Duke Leto (Isaac), and the mother of Paul (Chalamet). In the world ofDune, the Bene Gesserit is an all-female social, religious, and political order. The Bene Gesserit’s ultimate drive is to guide humanity along a path of insight and stability while also maintaining a notable amount of power and influence. Women in the Bene Gesserit order have developed mental and physical abilities that seem magical to others, including influencing others through small manipulations in their voice or, containing the entire genetic memory of their female ancestors within their minds.

Lady Jessica is one of these power players and is in even more of a position of power through her union with Duke Leto. Jessica is a key figure inDunebecause of her decision to consciously give birth to a male heir, Paul, rather than the daughter that the Bene Gesserit had predicted — a move that disrupts the political designs of the Bene Gesserit and the fates of Lady Jessica, Paul, and the rest of theDuneworld.

dune-rebecca-ferguson-lady-jessica

Josh Brolin as Gurney Halleck

Josh Brolinplays Gurney Halleck, a warrior-poet who also happens to be a trusted confidant to both Duke Leto (Isaac) and Paul (Chalamet). Gurney is the Warmaster for House Atreides, which means he has earned a strong reputation as a skilled soldier and keen military mind, two things he also trains Paul in (which we see in theDunetrailer). Over the course ofDune, Gurney is shown to be a protector figure to Paul. He is also a skilled musician and something of a sensitive man, a surprise twist for a high-ranking military official.

Javier Bardem as Stilgar

Javier Bardemis Stilgar, the leader (“naib”) of the Sietch Tabr, a Fremen tribe living in the deserts of Arrakis. Stilgar forms a friendship with Duncan Idaho (Momoa) upon Duncan’s arrival to scout out Arrakis. Through Duncan’s reports, Stilgar is recommended as a strong ally to Duke Leo (Isaac) and House Atreides. Stilgar and his tribe also end up taking in Paul (Chalamet) and Lady Jessica (Ferguson) after the Harkonnens attack House Atreides, resulting in mass casualties for Paul and his family.

Zendaya as Chani

Zendayaplays Chani, a Fremen young woman, is the daughter of Liet Kynes (Duncan-Brewster). Paul (Chalamet) dreams of Chani before he meets her upon moving to Arrakis. She is a love interest of Paul’s but she is notjusta love interest. A powerful figure in her own right, Chani is an incredibly skilled fighter and knows how to take full advantage of using spice. She becomes an important ally to House Atreides as her relationship with Paul deepens.

Jason Momoa as Duncan Idaho

Jason Momoais Duncan Idaho, a member of House Atreides and an extremely skilled fighter. Duncan is one of Duke Leto’s trusted right-hand men in addition to Gurney Halleck and Thufir Hawat. Duncan is also a skilled pilot, is a member of the Swordmasters of Ginaz (a martial arts school), and is superlative in hand-to-hand combat. He is sent to Arrakis with a small party ahead of the arrival of Duke Leto (Isaac) and the rest of House Atreides to get familiar with the new fiefdom now under the Atreides leadership. Oh, and Duncan’s also something of a ladies man, in case you were wondering.

Sharon Duncan-Brewster as Liet Kynes

Sharon Duncan-Brewsteris Liet Kynes, a person of science working as an Imperial Planetologist and ecologist. Kynes is also the mother of Chani (Zendaya). Originally written as a male character in Herbert’s books, Kynes will now be a woman in Villeneuve’s story. Kynes has made a life for herself on the desert planet of Arrakis, cultivating strong bonds with the Fremen people — so much so her daughter is half-Fremen. Kynes is also something of an intermediary between House Harkonnen and House Atreides when the latter group lands on Arrakis for the handover of control of the desert planet thanks to Kynes' invaluable knowledge of the planet.

Stellan Skarsgård as Baron Vladimir Harkonnen

Stellan Skarsgårdis Baron Vladimir Harkonnen, head of House Harkonnen and chief enemy of House Atreides. Harkonnen’s primary drive is to weaken House Atreides for political gain. A man of simple (if odious) motives, Harkonnen unleashes the full fury of his men onto House Atreides, thus making it the primary conflict ofDune. Harkonnen is secretly behind the decision for Duke Leto (Isaac), Paul (Chalamet), and House Atreides to take over on Arrakis, thus making them easier targets.

Dave Bautista as Glossu Rabban

Dave Bautistareunites with Villeneuve to play Glossu Rabban, a member of House Harkonnen. Rabban is also known as “The Beast,” “Mudir Nahya” (Demon Ruler), and “King Cobra.” He is the nephew of Baron Harkonnen (Skarsgård). While he is every bit as cruel and sadistic as the rest of his family, he’s not as insightful or cunning as them. Fortunately, he is relatively competent to the point that he reigns in tyranny on Arrakis in the name of House Harkonnen. As such, he’s a fairly malleable killing machine who works perfectly under his uncle’s thumb.

dune-josh-brolin-gurney-halleck