The upper age limit for participating in the Hunger Games is eighteen, and the lower age limit is twelve.
Every year, there is a ritual in each district called the reaping. During the reaping, all the children in a district are herded into roped-off areas. A lottery then takes place in which one boy and one girl are chosen from each district to be a tribute in the Games.
The older a person is, the greater their odds are of being chosen. When an individual is twelve, their name is entered into the lottery only once. However, for each year they are above twelve, their name is added an additional time. A thirteen-year-old’s name goes in twice, while an eighteen-year-old has their name entered seven times. This helps ensure that bigger and stronger teens are picked for the Games, making the event more exciting.
The wealthy people who live in the Capitol enjoy watching the reapings, which are held at different times in each district and televised. Many in the Capitol like to place bets on who will be chosen as a tribute.
To call the lottery that determines tributes a reaping shows how dehumanized the citizens of the districts are in the eyes of the Capitol. They are little more than things to be harvested for the benefit of the decadent wealthy class.