Lights, camera, action!
In the wondrous land of the future, the land of Panem squats where the United States used to be. A cruel Capitol rules 12 enslaved Districts with an iron fist and a wardrobe straight out of Lady Gaga's closet, while the District residents mainly root around in the dirt with the hogs. Once a year, one boy and one girl—called "Tributes"—from each District are chosen to participate in The Hunger Games, a gladiatorial battle to the death which is broadcast live throughout Panem. Most of the Districts are not cool with it, but the Capitol's fashionably dressed storm troopers say otherwise.
Such are the musings one fine day between Katniss Everdeen, a.k.a. Our Heroine, and her buddy Gale. The two have a habit of sneaking out past the fence in their District to go hunting in the forbidden woods, something the Capitol definitely frowns on. They've got a little thing going on, but Gale's more interested in how evil the Capitol is than in the upcoming selection process.
Katniss, for her part, has more pressing problems.
She's been looking after her little sister Primrose since their father was killed in the mines and their mother basically checked out. She's less interested in overthrowing the Capitol than in ensuring that her sister doesn't worry about the selection. After all, there's no way that Prim could be chosen for the Games, could she?
Yeah, about that…
Prim gets chosen and Katniss, stepping up like a big sister should, volunteers to take her place. It's kind of a shocker, since District 12 has never had a volunteer before. But what's a girl forced to grow up before her time gonna do?
She and the male Tribute, a handsome stack of baker's son named Peeta, stand together on the stage. In a flashback, we see that Katniss recalls seeing Peeta before—but the memory isn't complete.
The pair are whisked off to the Capitol to begin the primping that apparently precedes their imminent death. Katniss keeps staring at Peeta, and another flashback fills in some details; she saw him feeding pigs some burned bread from his family's bakery.
On the train to the Capitol, they meet Haymitch, the last survivor of the Games from their District, who's charged with advising them on what's about to happen. (Apparently, dispensing advice requires a lot of drinking.) They also meet Effie, who picked their names out of a hat and apparently is also part of their advisory team.
They arrive at the Capitol to great acclaim and quickly become celebrities. Their fashion guru Cinna designs outfits for them in the opening parade that appear to burst into flame, leading the Capitol media to dub Katniss "the Girl on Fire." Cinna knows how important it is to make a huge first entrance.
They spend several days training, planning, and watching the rest of the Tributes size them up like pieces of meat. Katniss makes a big impression by shooting an arrow through an apple in the mouth of a roast pig during her evaluation. That helps Haymitch score them sponsors that can buy them life-saving goodies in the Games battle arena. Peeta helps out by being a natural in front of the camera, and by confessing his love for Katniss, which Katniss is reasonably not-cool with.
Turns out to be a good strategy—the Capitol knows a ratings booster when they see it.
The Hunger Games arrive, and before Katniss is let loose, Cinna slips her a little present: the pin of a mockingjay (bird of the future and convenient symbol of defiance when the Capitol gets all up in your business) that she got from her sister when she volunteered to take her place.
Then we're up through the magic tube and into the arena, a faux wilderness where the Tributes fight like dogs for food, weapons, and anything to save them from various bits of heinosity that the Capitol throws at them. About half the Tributes are dead at the end of the first day. Katniss survives for a time by steering clear of anyone else, but a Capitol-engineered fire sends her back into danger. She soon runs afoul of a group of bigger, stronger kids, including Peeta, who appear to be making deals to stay alive and chase her straight up a tree.
She survives with a little help form Rue, a small, young Tribute who's good at hiding in trees, and with a nest of genetically engineered death wasps called tracker jackers that she drops right on her pursuers' faces. She gets a few stings herself and takes a magical trip through time and space thanks to their hallucinogenic poison, though she manages to snag a bow and arrow in the process.
She wakes up sometime later, with Rue watching over her. The little girl tended her wounds and kept an eye out for danger. They plan and successfully execute the sabotage of the group that's been pursuing them. Unfortunately, one of the other kids kills Rue with a spear right afterwards. Katniss kills him.
Only a few Tributes are left at this point.
Back outside the arena, where people aren't slaughtering each other, Haymitch convinces the Games coordinators to change the rules to allow two winners if they both come from the same District. Shortly after the announcement, Katniss comes across Peeta, camouflaged as a log and badly wounded. She nurses him back to health with help from a bowl of soup from a sponsor, helping to enhance the blossoming-but-not-quite-there-yet love triangle between the two of them and Gale. (And for the record, we are totally Team Peeta around here. Crusaders like Gale make lousy boyfriends.)
Unfortunately, Peeta needs medicine as well as just TLC. Luckily the generous Capitol offers to provide it, along with things that the other survivors need. Katniss just has to get the the center of the arena to get it, and Peeta tries to talk her out of it because, well, she could get killed. Like a sensible girl, she agrees; then when he's asleep, she leaves.
Katniss arrives in the center of the arena, and barely survives an attack from a Seriously Crazy Young Lady. She's saved by a boy from Rue's District, who does it in honor of the dead girl. She beats a hasty retreat with the medicine, and soon enough Peeta is ready to rock and roll.
Emerging form their hiding place, they come across another contestant who died after eating poison berries. They pocket some of the berries just in case.
Soon enough, it's just the two of them, along with Cato, the leader of the band who had chased Katniss. They battle at the arena center after the Capitol unleashes giant dogs to hunt them down. The three survive by climbing to the top of the giant cornucopia in the middle of the arena, and, after a brief-but-terrifying game of chicken, Peeta chucks Cato to the beasts.
High five for the good guys.
Except…the Capitol changes their mind again and now announces that only one victor can emerge. After a brief discussion, Peeta and Katniss agree to eat the poison berries together, and they make sure everyone is watching on their screens.
And guess what? The Capitol changes their minds again and lets them live.
Katniss and Peeta are the victors, but, having stuck their collective finger in the Capitol's eye, are advised to seriously watch their backs in the future. Seneca Crane, the Games creator who obviously has mismanaged it bigly this time, finds himself locked in a room with nothing but a bowl of poison berries.