The Hunger Games takes place after the destruction of North America by some unknown apocalyptic event, in a nation known as Panem. Panem consists of a wealthy Capitol and twelve surrounding, poorer districts. District 12, where the book begins, is located in the coal-rich region that was formerly Appalachia
As punishment for a previous rebellion against the Capitol in which a 13th district was destroyed, one boy and one girl between the ages of 12 and 18 from each district are selected by annual lottery to participate in the Hunger Games, an event in which the participants (or "tributes") must fight in an outdoor arena controlled by the Capitol, until only one remains. The story follows 16-year-old Katniss Everdeen, a girl from District 12 who volunteers for the 74th annual Hunger Games in place of her younger sister, Primrose. Also selected from District 12 is Peeta Mellark, a baker's son whom Katniss knows from school, who once gave her bread when her family was starving.
Katniss and Peeta are taken to the Capitol where their drunken mentor, Haymitch Abernathy, victor of the 50th Hunger Games, instructs them to watch and learn the talents of the other tributes. They are then publicly displayed to the Capitol audience in a televised session with interviewer Caesar Flickerman. During this time, Peeta reveals on-air his long-time unrequited love for Katniss. Katniss believes this to be a ploy to gain audience support for the Games, which can be crucial for survival, as audience members are encouraged to send gifts like food, medicine, and tools to favored tributes during the Games. The Games begin with 11 of the 24 tributes dying in the first day, while Katniss relies on her well-practiced hunting and outdoor skills to survive. As the games continue, the tribute death toll increases. A few days later, Katniss develops an alliance with Rue, a 12-year-old girl from the agricultural District 11 who reminds Katniss of her sister Prim. The alliance is short-lived: Rue is killed by another tribute. At Rue's request Katniss sings to her, then spreads flowers over her body as a sign of respect—and of disgust towards the Capitol.
Supposedly due to Katniss and Peeta's beloved image in the minds of the audience as "star-crossed lovers", a rule change is announced midway through the Games, stating that two tributes from the same district can win the Hunger Games as a pair. Upon hearing this, Katniss searches for Peeta and eventually finds him wounded. As she nurses him back to health, she acts the part of a young girl falling in love to gain more favor with the audience and, consequently, gifts from her sponsors. When the couple are finally the last two tributes, the Gamemakers reverse the rule change in an attempt to force them into a dramatic finale, where one must kill the other to win. Katniss, knowing that the Gamemakers would rather have two victors than none, retrieves highly poisonous berries known as "nightlock" from her pouch and offers some to Peeta. Upon realizing that Katniss and Peeta intend to commit suicide, the Gamemakers announce that both will be the victors of the 74th Hunger Games.
Although she survives the ordeal in the arena and is treated to a hero's welcome in the Capitol, Katniss is warned by Haymitch that she has now become a political target after defying her society's authoritarian leaders so publicly. Afterwards, Peeta is heartbroken when he learns that Katniss's actions in the arena were part of a calculated ploy to earn sympathy from the audience. However, Katniss is unsure of her own feelings, and realizes that she is dreading the moment when she and Peeta will go their separate ways.