In Westeros, bastards (also 'natural child' or 'baseborn') born to nobles are given surnames different than their father's, according to the region they were born in. These surnames are mostly associated with the geographic or climatic features of the respective regions: in the Reach - the bastards' surname is Flowers; in the Westerlands - Hill; in the Iron Islands - Pyke; in the Riverlands - Rivers; in Dorne - Sand; in the North - Snow; in the Vale - Stone; in the Stormlands - Storm; in the Crownlands - Waters. The special surnames apply only to noble-born bastards, who are openly acknowledged by their noble parent. Therefore, bastards both of whose parents are commoners, or noble-born bastards that are unacknowledged by their noble parent (like Gendry) cannot use the special surname. A noble-born bastard can be legitimized by royal decree, thus is considered as trueborn child and changes the surname to the father's. However, the social stigma of the bastardy may not always be lifted even after legitimization.
Many of the characters have nicknames, mostly based on specific deed, behavior or physical feature of the person in question. The nicknames can be derogatory (Kingslayer) or for mockery (Brienne the Beauty). For example: Eddard Stark - Ned; Jaime Lannister - the Kingslayer; Tyrion Lannister - the Imp or Halfman; Varys - the Spider; Sandor Clegane - the Hound; Gregor Clegane - the Mountain that Rides (or simply the Mountain); Petyr Baelish - Littlefinger; Jeor Mormont - the Old Bear; Loras Tyrell - Knight of Flowers; Aerys Targaryen - the Mad King; Viserys Targaryen - the Beggar King;Melisandre - the Red Woman; Robb Stark - the Young Wolf; Brienne - the Beauty; Qhorin - Halfhand; Mance Rayder - the King Beyond the Wall; Davos Seaworth - the Onion Knight; Jon Umber - Greatjon.
Author George R.R. Martin was asked if he had a resolution or ending to the seemingly endless conflict. He replied that the end would be a cloud of dust or snow being driven by the wind across a vast graveyard full of tombstones.
The first season used Northern Inuit dogs, a type specifically bred for wolf-like appearance, to stand in for the direwolves (the Stark's house sigil). However, since direwolves are known to be much larger than normal wolves, real wolves were digitally composited into scenes for season 2. This strained the budget and the schedule, hence why there are only a handful of scenes with Grey Wind (Robb Stark's wolf), Summer (Bran Stark's wolf) and Shaggydog (Rickon Stark's wolf); Ghost, who belongs to Jon Snow, is shown in brief glimpses.
Carice van Houten was previously asked to audition for a different role when season 1 was shot, but schedule conflicts prevented her from auditioning. She was asked to come back to audition during shooting of season 2, and was cast as Melisandre.
The official words of House Lannister "Hear Me Roar!" are seldom mentioned. Their unofficial motto "A Lannister always pays his debts" is often used, mostly in negative context, meaning that Lannisters always repay unkindness with unkindness.
While most of the show is largely faithful to the books, composite characters do appear. The most prominent is the prostitute Ros, who is a composite of several named (Alayaya, Chataya, Kyra) and unnamed characters from the book series. Another composite character is the Spice King, who appears in Season Two.
Yara Greyjoy, introduced in the second book and season, is named Asha in the books. The name was changed for the television series to avoid confusion with Osha. However, in the German dubbed version she is called Asha, like in the books.
The naturally brunette Emilia Clarke captured the eyes of audiences around the world when she first appeared as the blonde Daenerys Targaryen in the show, nabbing the role after fellow British actress Tamzin Merchant dropped out of the pilot for undisclosed reasons.
The series takes its name from the first novel in the book series - "A Game of Thrones" - which is actually known as "A Song of Ice and Fire." George R.R. Martin's story credit acknowledges the entire series under this title, rather than the title of individual volumes.
Features actors from two different adaptations of The Lord of the Rings: Peter Vaughan, who played Denethor in the BBC Radio adaptation; and Sean Bean, who played the character's son Boromir in the Peter Jackson films.
According to the novels, the sigil of House Baratheon is a black stag with a crown above its head on a field of gold. In the TV series, the Baratheons' banner depicts a stag with a crown around its neck.
The trivia items below may give away important plot points.
George R.R. Martin has stated that the infamous "Red Wedding" was the hardest chapter for him to write in "A Storm of Swords." He was so emotionally attached to the characters that he actually wrote the rest of the book first, and then that chapter last. David Benioff and D.B. Weiss, upon reading it, declared it was one of the major reasons they decided to option the books for a television series. Their dramatization differs from the book in a few details. Most notably, Robb's wife is not present at the wedding, nor is she pregnant.
For the most part, Season 2 is based on the second novel in the series "A Clash of Kings". However, some of the plot points from later in the season, such as Catelyn releasing Jaime Lannister, and Robb breaking his betrothal to House Frey; are actually taken from the early chapters of the third novel "A Storm of Swords". The writers have also said that, given the length of the third book, they are not likely to finish it in the ten episodes given to each season, so it will likely spill over into the fourth season. It is also likely that the fourth and fifth novels ("A Feast for Crows" and "A Dance with Dragons") may both be used as source material for a fourth and fifth season, as none of the same characters appear in both novels, which are meant to take place simultaneously.
Series author George R.R. Martin reported on his blog that after the filming of the episode in which Sansa's direwolf Lady is executed, the dog that played Lady, a Northern Inuit named Zunni, was adopted by Sophie Turner, the actress who plays Sansa.