Differences between books and TV series - Season 3

Game of Thrones (Season 3) vs A Storm of Swords (book) Spoilers may follow.

Valar Dohaeris

 * Samwell Tarly is on the Fist of the First Men during the White Walker/Wight attack. He did send out the ravens, but only two of them carried a message.
 * Ghost is not present during the battle, he's with Jon Snow.
 * ​The remaining brothers of the Night's Watch were all on horseback after their escape.
 * In the books, Rast was never present at the Fist of the First Man as he remained a recruit and stayed at Castle Black
 * In the novels, giants wear no clothing, they are covered in shaggy fur pelts like mammoths. They are much more like descriptions of a sasquatch or yeti.
 * In the novels, when Jon Snow enters Mance Rayder's tent, Mance is singing a song, which makes Jon think of him as a singer and not the King-Beyond-the-Wall.
 * Mance's wife Dalla and her sister Val are not present when Jon encounters him
 * Jon does not kneel before Tormund.
 * Mance Rayder tells Jon that he visited Winterfell as a singer during King Robert Baratheon's visit.
 * ​Jon gives a very different reason as to why he wants to join the Free Folk, involving his bastardy and upbringing in Winterfell.
 * Tywin Lannister visited Tyrion many times while he was unconscious.
 * Podrick Payne mentions that Bronn was anointed by the King himself. In the book, Bronn is anointed by a member of the Kingsguard.
 * ​The scene with Sansa Stark and Shae does not happen in the book.
 * Petyr "Littlefinger" Baelish never approached Sansa Stark directly with his offer of escape, but acted through an intermediary.
 * Baelish neve​r tells Sansa that Arya is alive, as he never visits Harrenhal to observe her as Tywin's cup bearer.
 * It isn't clear if Littlefinger is simply meant to be lying, and never recognized Arya at Harrenhal. Particularly given that Littlefinger doesn't know that Arya escaped Harrenhal, and moreover, that Harrenhal falls to the Starks in this episode, it wouldn't make sense for Littlefinger to realize that Arya was at Harrenhal but do nothing to let her fall out of his control. Compare that he earlier lied to Catelyn about having both Sansa and Arya in King's Landing.
 * ​The scene between Tyrion and Cersei Lannister in Tyrion's chambers does not happen in the book.
 * ​The scene where Margaery Tyrell comforts the orphans and hands out food does not happen in the book, though loosely happens "off screen" as it is reported to Tyrion that Margaery is deftly building up support for herself among the commoners by handing out food aid.
 * ​The dinner scene with the Tyrells and Lannisters does not happen in the book.
 * Davos Seaworth was stranded on a tall spire of rock, not a conical island.
 * Davos was rescued by one of Salladhor Saan's captains, not Saan himself.
 * Davos was not taken to see Stannis Baratheon for months as he was thrown in the dungeon almost the moment he set foot on Dragonstone.
 * ​Neither Catelyn nor Robb Stark went to Harrenhal.
 * Qyburn was therefore never encountered at Harrenhal having survived a massacre.
 * By this time in the bo​oks, Harrenhal was already owned by Roose Bolton.
 * The conversation b​etween Rickard Karstark and Roose Bolton never happened in the books
 * Astapor is constructed of crumbling red bricks in the novels.
 * The Unsullied training also includes the recruits raising a puppy for a year before strangling it to death. Also unmentioned is that during their training the Unsullied are given a potion to drink known as the Wine of Courage, which gradually deadens their bodies' sensitivity to pain. In the books, it is stated that only one in three boys survive the years of training to become Unsullied, while the TV series says that only one in four boys survives.
 * ​Daenerys is seen traveling with only one ship in TV series. In books she travels with three ships named "Vhagar", "Meraxes" and "Balerion".
 * ​The ships were sent by Illyrio Mopatis in the books. In TV series, she bought one ship after she had looted Xaro's mansion in Qarth.
 * ​The assassination attempt on Daenerys Targaryen is made back in Qarth, before she leaves for Astapor. It is also not made by the Warlocks, but by a Qartheen guild of assassins known as the Sorrowful Men.
 * Ser Barristan Selmy​ does not reveal his identity until much later in the book.
 * This change is plot line is the one which could not be avoided as disguising a character in appearance for a TV serial is more difficult than doing so in the books.
 * Daenerys first plans to go to Pentos, but takes a detour to Astapor on Ser Jorah Mormont's insistence.
 * Ser Barristan is accompanied by Strong Belwas in the books, while this character has yet to appear.
 * Ser Barristan's white hair and beard have grown long as part of his disguise.

Dark Wings, Dark Words

 * Jojen and Meera Reed are introduced much eralier in the books, still in Winterfell
 * Jojen Reed is a lot younger in the books ​
 * The people that finds Jamie Lannister and Brienne are the Brave Companions, not Bolton's men​
 * Cleos Frey is with Jaime and Brienne in the book. It was his sword that Jaime took when he dueled Brienne.
 * Lord Karstark never expresses any thoughts about losing the war in the book.
 * Catelyn Stark's tale about cursing Jon Snow with pox is never mentioned in the book.
 * Sandor Clegane does not appear until much later in the book. He does not reveal Arya's true identity to to the Brotherhood Without Banners. It is Harwin who reveals her true name.
 * Osha, Rickon and Shaggydog had split up from Bran, Hodor, Summer and the Reeds much beforehand in the book.
 * The events in the Dreadfort involving Theon Greyjoy are not mentioned in the books until A Dance with Dragons. The reader was left wondering if Theon had survived the Battle of Winterfell.
 * The character of Orell appears in this episode, but in A Clash Of Kings, he was slain by Jon Snow shortly before he encountered Ygritte for the first time. Technically Orell should not appear in the third season. He lives on by warging in his eagle.

​See also:

 * ​Differences between books and TV series - Season 1
 * Differences between books and TV series - Season 2