The Hunger Games by Suzanne Collins

Katniss is a 16-year-old girl living with her mother and younger sister in the poorest district of Panem, the remains of what used be the United States. Long ago the districts waged war on the Capitol and were defeated. As part of the surrender terms, each district agreed to send one boy and one girl to appear in an annual televised event called, "The Hunger Games." The terrain, rules, and level of audience participation may change but one thing is constant: kill or be killed. When Kat's sister is chosen by lottery, Kat steps up to go in her place.