The Hunger Games were a morbid and brutal competition which took place annually in the country of Panem. Every year, one boy and one girl between the ages of 12 and 18 were selected from each of the twelve Districts as tributes, who prepare for a week and then are sent into an outdoor arena to fight to the death. The event was nationally televised as mandatory viewing for all citizens. The last living tribute is declared the victor and is allowed to live in comfort in their home district.
main article the Reaping
Every year, each District hosts a Reaping ceremony. Two large glass balls contain slips of paper with each child's first and last name. A child's name is entered each year for every year that they are eligible. The entries are cumulative, and each year another slip is added to the glass ball for the child's aging. By the time each child is 18, they must have a minimum of 7 entries in the glass ball. However, they can choose to add their name more times in exchange for tessera, which is a small ration of grain and oil.
The District escort picks a name out of the balls, one of which is for girls and one for boys. The tributes whose names are chosen are then entered into the Hunger Games, unless someone is willing to volunteer - a normally quite rare phenomenon unless it is in one of the "Career Districts", districts in which children have been training their whole lives to enter the Games.