24 tributes. 1 winner. 

The country of Panem stands on what once used to be North America. 
It consists of a Capitol surrounded by 12 outlying districts.
As punishment for the Dark Days, when the people rebelled against the Capitol, they take a girl and a boy between the ages of 12 and 18 from each district to compete in the Hunger Games every year. This is a punishment to remind them to never repeat the Dark Days ever again. The Games are brutal. All the competitors are placed into a vast outdoors arena for weeks on end to kill other players and fend for themselves, all on live TV.  Survival of the fittest. The last player still alive wins the games, as well as a life of luxury back home. 

Katniss Everdeen, age 16, has been single- handedly been taking care of her family for years. When her dear sister, Prim, has her name drawn, Katniss steps up to take her place, even if it means almost certain death. Now she must leave everyone she cares about and go to the Capitol along with Peeta Mellark, the boy tribute from district 12, to compete in the Games.

The Districts: each district specializes in a different industry to provide goods for the Capitol
district 1: luxury items
district 2: weapons
district 3: electronics
district 4: fishing
district 5:
district 6: medicine
district 7: timber and paper
district 8: textiles
district 9: food processing
district 10: livestock
district 11: agriculture
district 12: coal mining
district 13: no longer present-  it was bombed by the Capitol during the Dark Days, but they used to make nuclear weapons

An estimation of the country of Panem