The situation leading to the war included China invading Alaska, and the United States annexing Canada. The European Commonwealth dissolved and a world wide conflict followed when each country tried to gather what natural resources it could. This period was known as the Resource Wars.
The game takes place in the year 2277 on the East Coast of what used to be the United States of America. The player character, known as the Lone Wanderer, is a young inhabitant of Vault 101, a fallout shelter in the Washington D.C. area. The vault has reportedly been sealed for 200 years, until the player's father, James, opens the only door to the outside world and disappears without any explanation.