Well known in District 12 for her hunting skills, Katniss has an overwhelming instinct to protect the people she loves, and a strong will to survive. When her young sister is chosen for the Hunger Games, Katniss volunteers to take her place. The same skills and stubbornness that helped save Katniss's family from starvation after her father's death enable her to survive in the arenas in The Hunger Games and Catching Fire. Eventually, she joins the rebels' resistance, where her hatred of the Capitol turns her into one of the rebels' most powerful weapons in Mockingjay.
The son of a baker, Peeta Mellark is a charismatic and kind boy with an innate gift for communication and persuasion in The Hunger Games. Believing he stands no chance of winning the Games, he decides to do whatever he can to help Katniss Everdeen, whom he has loved from afar since kindergarten. Helping and supporting Katniss becomes the focus of Peeta's life until the Capitol hijacks his memories of her, and brainwashes him into becoming the government's mouthpiece. Fighting through his altered perceptions, he holds to his promise to always stay with Katniss.
Skilled at trapping, Gale Hawthorne is Katniss Everdeen's match in temperament and background. He hunts with Katniss to provide for his family after his father is killed. He hates the Capitol and eagerly hopes for an uprising. When the Capitol firebombs District 12, Gale leads several hundred of the residents to safety. He quickly becomes a rebel leader in District 13, where his thirst for revenge unleashes a darker, more vicious side of his personality in Mockingjay.
Haymitch is a fascinating character, and readers' perceptions of him change throughout the series. At first appearing to be no more than a worthless drunk, his flaws are eventually revealed to be the result of the unimaginable pain, loss, despair, and self-loathing he experienced in order to become a victor in one of the Quarter Quells, which occur every 25 years. But he is also shrewd and very intelligent, coaching Katniss throughout the 74th Games and secretly working with the rebel resistance to bring down the Capitol in both Catching Fire and Mockingjay.
Snow is one of the most frightening figures in the series. He is deceptively well-mannered and immaculately dressed, but Katniss often compares him to a snake. She also vividly describes how the enhanced fragrance of the white roses Snow wears mix sickeningly with the smell of blood on his breath. Snow has been president of Panem for years, and although he may originally have worked to maintain order in the nation, that impulse has been replaced by his own "hunger" for absolute power and a willingness to do anything to retain it. He warns Katniss he will kill her friends and family if she does not help suppress the growing unrest in the nation. By the end of Mockingjay, though, Snow becomes a prisoner in his own mansion, waiting to be executed by the rebels.
Prim is not seen through much of The Hunger Games, but she is the catalyst for much of what happens, the voice of kindness and compassion, and the force that drives Katniss. Katniss's love for Prim is what causes her to volunteer for the Hunger Games, and Rue's resemblance to her sister gives her hope during the Games themselves. Prim herself grows stronger and braver as events unfold, even taking on the duties of medic so she can help others. Her death at the end of the series—where she becomes a "human torch" when the Capitol is bombed by the rebels—sends Katniss into a black despair from which she never entirely recovers.
Finnick first appears in Catching Fire as the handsome and charismatic former victor from District 4, who has the reputation as a smooth talker and ladies' man. During the Quarter Quell, however, he reveals himself to be skilled, intelligent, and loyal, helping ensure both Katniss's and Peeta's survival. Readers also learn in Mockingjay that far from being a ladies' man, he has loved only one woman—a girl named Annie Cresta, who was mentally and emotionally broken during her own time in the Games. He was also "sold" by the Capitol to various citizens, but turned the humiliation to his advantage by learning secrets about the people there, including the fact that Snow poisoned anyone who stood between him and the power he sought. Finnick has a brief moment of happiness when he eventually marries Annie, but he is killed in the sewers in Mockingjay as he and the Star Squad fight their way to the Capitol.