A Game of Thrones takes place over the course of one year on or near the fictional continent of Westeros. The story begins when King Robert visits the northern castle Winterfell to ask Ned Stark to be his right-hand assistant, or Hand of the King. The previous Hand, Jon Arryn, died under suspicious circumstances. Robert comes with his queen, Cersei Lannister, and his retinue, which includes a number of Lannisters. Just after the royal party arrives, Ned’s wife, Catelyn, receives a message claiming that the Lannister family was responsible for the death of the former Hand. She tells Ned, who accepts the position as Hand in order to protect Robert from the Lannisters. Ned’s son Bran then discovers Cersei Lannister and her brother Jaime Lannister having sex, and Jaime pushes Bran from a window to silence him. Everyone thinks Bran simply fell while climbing around the castle. While Bran is still unconscious, Ned leaves Winterfell and rides south with Robert. The same day, Ned’s bastard son, Jon, leaves to serve at the Wall, a massive structure that protects Westeros from the wilderness of the far North. The group of men sworn to defend the Wall, the Night’s Watch, have been receiving reports of strange creatures and have been losing men with increasing frequency. Tyrion Lannister, a little person who is brother to Cersei and Jaime, travels with Jon to the Wall to see the massive structure. Meanwhile, on a continent east of Westeros, Daenerys Targaryen marries the warlord Khal Drogo, one of the leaders of the Dothraki people. Daenerys and her brother Viserys are the last surviving members of the family Robert defeated to become king, the Targaryens. They are an old family said to be descended from dragons, and Viserys thinks with Khal Drogo’s army he can retake the throne. A knight named Ser Jorah Mormont, exiled by Ned Stark, pledges he will help. Daenerys receives three dragon eggs as a wedding gift and becomes immediately fascinated by them.
On the trip south to the capital, called King’s Landing, Robert’s and Cersei’s son, Joffrey, and Ned’s daughter Sansa, who everyone presumes will be married one day, go for a walk. When Joffrey sees Arya, Ned’s other daughter and sister to Sansa, practicing her swordfighting with a boy, he decides to show them he’s a better fighter. As pets, all of the Stark children have direwolf pups, a wolf breed larger than normal wolves that also happens to be the symbol of the Stark house, and Arya’s wolf injures Joffrey defending her. Though Sansa knows Joffrey instigated the fight, she will not tell on Joffrey because she’s in love with him. As punishment, Cersei wants Arya’s wolf killed, but since it ran away after hurting Joffrey, Cersei demands that Ned kill Sansa’s wolf instead. Meanwhile, an assassin tries to kill the unconscious Bran and fails. Ned finally reaches King’s Landing to find that Catelyn has sailed to the city in secret to discover the truth about the assassin. She has the dagger the assassin used, and after examining it, Catelyn’s childhood friend Littlefinger recognizes it as belonging to Tyrion Lannister. Ned tells Catelyn he will try to determine who killed the former Hand, Jon Arryn, and tried to kill Bran. Bran finally wakes from his coma, but he doesn’t remember how he fell. Tyrion visits him on his way south from the Wall to deliver a greeting from Jon. Tyrion continues south as Catelyn starts back north, and when their paths cross Catelyn has him seized for trying to kill Bran.
In King’s Landing, Ned slowly begins to unravel the mystery of why the previous Hand was killed. He knows it has to do with something the Hand learned about King Robert’s children. Through a spy, Robert learns that Daenerys Targaryen is pregnant. He wants to assassinate her because he fears she and her son will one day challenge Robert’s right to the throne. Disgusted with Robert’s plan, Ned resigns as Hand. That night, Jaime and his men confront Ned about Tyrion’s capture. Jaime kills Ned’s men and Ned breaks his leg while fighting. The following day, Robert reinstates Ned as hand. While Robert is gone hunting, Ned orders the execution of a rogue knight loyal to the Lannister family who has been pillaging villages. Further north, Catelyn takes Tyrion to her sister Lysa Arryn’s castle, the Eyrie, which is in a mountainous area called The Vale. Lysa accuses Tyrion of arranging the murder of both Jon Arryn and Bran. Tyrion denies the accusations and demands a trial by combat. A knight fights on Lysa’s behalf, and a mercenary fights on Tyrion’s behalf. Tyrion’s mercenary wins. While Tyrion rides from the Eyrie, a group of mountain clansmen try to kill him, but he promises to help them take The Vale and convinces them to join him.
In the east, as Khal Drogo and his Dothraki followers head back to Vaes Dothrak, their capital, Viserys becomes increasingly angry that Drogo has not provided him with an army with which to wage war on Westeros. During a feast he attacks Daenerys in a rage, and Khal Drogo has Viserys killed by dumping molten gold on his head. In King’s Landing, Ned has figured out why the Hand was killed: he had discovered that Joffrey was not really Robert’s child but was actually the product of Cersei’s sexual relationship with her brother, Jaime. Robert doesn’t know the truth. Robert is mortally wounded in a hunt, and before he dies, he names Ned the Protector of the Realm, essentially an interim king, until Joffrey comes of age. Ned does not tell Robert that he knows Joffrey is not the true heir, since he is the son of Cersei and Jaime. Ned asks Littlefinger’s help to install the true heir, Robert’s brother Stannis, as the king, and Littlefinger agrees. But when Ned confronts the Lannisters, saying that Joffrey is not the true heir and expecting Littlefinger’s support, Littlefinger betrays him, and Cersei imprisons Ned for treason. Meanwhile, north of the Wall, Jon and other men have discovered two strange dead bodies. They bring the bodies back for examination, and late at night, one of the bodies comes to life and tries to kill Jon’s commander. Jon and his direwolf fight off the undead body, and Jon kills the creature with fire.
After Ned’s capture, Arya escapes the castle in King’s Landing and Cersei holds Sansa hostage (she says she is holding Sansa for her own protection). Tywin Lannister, father to Tyrion, Cersei, and Jaime, wages war with Catelyn and her son, Robb Stark. Shrewdly outmaneuvering Tywin, Robb manages to defeat a portion of the Lannister army and capture Jaime. In King’s Landing, Joffrey, who is considered Robert’s heir, is crowned King. In the hopes that he can prevent his daughters being harmed, Ned confesses publicly to treason, and Joffrey has him executed while Sansa watches. Arya is in the crowd, though nobody knows it. Learning of his father’s death and his brother’s march to war, Jon tries to desert the Wall. But Jon’s friends convince him that he must stay and defend the Wall as he vowed. In the east, Drogo suffers a wound while raiding a village. Daenerys has one of the village women treat him, but he becomes very sick. When he is about to die, Daenerys asks the woman to heal him, but she says only bloodmagic will save him and it will require a death in exchange for his life. Despite the protests of the Dothraki people, Daenerys has the woman do it. Shortly thereafter Daenerys goes into labor. When she wakes many days later, her child is dead and Drogo is alive but brain dead. His followers have all left, leaving behind only a few warriors, the sick and old, and Ser Jorah Mormont, who has become one of Daenerys’s most trusted advisors. Daenerys sets a funeral pyre to burn Drogo and the woman, who tricked her and essentially killed her husband and child. Daenerys also places the three dragon eggs into the pyre. As the fire burns, Daenerys walks into it, and when finally it clears, Mormont and the Dothrakis find her with three newborn dragons at her breast.