What is Game of Thrones?

In the four years since Game of Thrones premiered, phrases like "winter is coming" and "valar morghulis" have entered the American lexicon, leaving fans eager for the Sunday-night show full of backstabbing, bloodletting, and fiery dragons. The fifth season is currently showing on HBO. Whether you need a refresher on the insanity of the last three seasons, or haven't seen a single episode and missed every battle, we've got you covered. Read along to prepare yourself for the Iron Throne.

The Iron Throne. Courtesy of South By Southwest Festival

What the show is all about

Game of Thrones is an HBO series that tells the story of a medieval country's civil war. The series, which premiered in April 2011, is set on the fictional continents of Westeros and Essos in a world where seasons stretch on for years. When the story begins, a decade-long summer is ending, and winter looms as characters battle to claim the "Iron Throne," the seat of the king of the Seven Kingdoms, the regime that rules all but the northern tip of Westeros. In show parlance, "sit on the Iron Throne" is a metonym equivalent to "rule Westeros."

The plot

The show is divided into three major plot lines. The first covers the battle between the lords of the continent of Westeros — most notably members of the Baratheon, Lannister, and Stark families — who are involved in the fight for the Iron Throne. The second follows the rise of Daenerys Targaryen, the last member of an exiled family as she builds an army in Essos to reclaim the throne. The third plot takes place in the North of Westeros among the Night's Watch, an armed unit that guards the 300-mile-long, 70-foot-tall wall that protects the rest of the continent from the mythical creatures that lurk there.

The cast

The show has an ensemble cast that includes Peter Dinklage — who won an Emmy for his role as Tyrion Lannister — Lena Headey, Natalie Dormer, Emilia Clarke, Kit Harington, Aidan Gillen, Nikolaj Coster-Waldau, Charles Dance, and Maisie Williams.

When is it on?

The fifth season of Game of Thrones premiered on April 12, 2015. It airs Sunday nights at 9 pm Eastern on HBO.

As Queen Cersei says in season one, "When you play the game of thrones, you win or you die. There is no middle ground."

*Be forewarned. This explainer is littered with spoilers through the end of season 4.*