[Editor's note: The following contains some mild spoilers for Dune.]

It's officially time to get excited for Dune, the sci-fi epic directed by Denis Villeneuve and adapted from Frank Herbert's 1965 novel of the same name. This is the second time Dune has made its way to the big screen, in addition to David Lynch's 1984 adaptation. As such, there's a good chance older fans of Dune will be familiar with the characters of this unusual world.

But, if you're new to or curious about the world of Dune and 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 know Oscar Isaac from Jason 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 key Dune cast members and an explainer of who they play as well as their role in the story. If you're new to the world of Dune or 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 arrives in theaters on December 18. For more, check out our full trailer breakdown and explanations of what's in that pain box and what that sandworm is.

Timothée Chalamet as Paul Atreides

Timothée Chalamet is Dune'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 in Dune: A super-being referred to as the "Kwisatz Haderach."

Oscar Isaac as Duke Leto Atreides

Oscar Isaac is the noble Duke Leto Atreides I, partner to Lady Jessica (Ferguson) and father of Paul (Chalamet). At the start of Dune, 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 Ferguson is Lady Jessica, a member of the Bene Gesserit, the concubine of Duke Leto (Isaac), and the mother of Paul (Chalamet). In the world of Dune, 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 in Dune because 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 the Dune world.

Josh Brolin as Gurney Halleck

Josh Brolin plays 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 the Dune trailer). Over the course of Dune, 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 Bardem is 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

Zendaya plays 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 not just a 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 Momoa is 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-Brewster is 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 Skarsgård is 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 of Dune. 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 Bautista reunites 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.

Charlotte Rampling as Gaius Helen Mohiam

Charlotte Rampling plays Gaius Helen Mohiam, the Reverend Mother of the Bene Gesserit. Mohiam is responsible for Lady Jessica's (Ferguson) Bene Gesserit training and also oversees Paul's (Chalamet) Gom Jabbar Test of Humanity which requires Paul to put his hand into a box to test if he is truly human. Paul not only withstands the test but exceeds expectations, even draining some of Mohiam's lifeforce in the process. Until Paul was tested, no male child has ever performed that well during the test with the gom jabbar.

Chen Chang as Dr. Wellington Yueh

Chen Chang portrayed Dr. Wellington Yueh, a member of the House Atreides team who is, in fact, a double agent for House Harkonnen. A trained doctor, Yueh's skills make him a prime target for Baron Harkonnen, who forces Yueh to work for him by taking Yueh's wife, Wanna, hostage. Yueh enters into House Atreides as the trusted physician to Duke Leto (Isaac) in an effort to get as close as possible to Leto and Lady Jessica (Ferguson) and feed information back to Harkonnen. Yueh is soon made into a pawn in the larger clash between House Harkonnen and House Atreides.

Stephen McKinley Henderson as Thufir Hawat

Stephen McKinley Henderson will play Thufir Hawat, the Mentat of House Atreides. As a Mentat, Hawat is essentially a human computer with the mental capacity and analytical ability exceeding that of an AI being or computer (as we know them) since the humans of Dune have grown to eschew actual computers or robots. Hawat's skills in processing data and analyzing them making him one of the most reputable Mentats of his time. He is more than just a human computer, too. Hawat also a trusted advisor to House Atreides and is responsible for Paul Atreides (Chalamet) training as a Mentat and is responsible for Atreides security, having trained the family members in anti-espionage and risk management.

David Dastmalchian as Piter de Vries

David Dastmalchian will play Piter de Vries. In the world of Dune, Piter is a member of House Harkonnen and thus loyal to Baron Harkonnen (Skarsgård). He is the Mentat of House Harkonnen, which means that, like Thufir Hawat, he is a human who has become more mentally skilled and astute than computers. He is also referred to as a "twisted Mentat," meaning he's become corrupted and is more likely to behave sadistically.

Allie Gemmill is the Weekend Contributing Editor for Collider. You can follow them on Twitter @_matineeidle.