I don't want to set the world on fire...

Two centuries after the Great War of 2077 that destroyed most of civilisation, Super Mutants, Ghouls, evermore hydrogen-powered robots, and other dangers roam the Wasteland among the descendants of lucky survivors, or Vault-dwelling hermits who still leave their shelters for one reason or another. 

Many factions vie for power and control in the Wasteland. 

• The power-armour-clad Brotherhood of Steel, with swathes of technology and disdain for anything non-human, making them the targets of most attacks by humans and wildlife alike.
• The vault dwellers, civilised, often education, and in some cases still sheltered and oblivious to the devastation that awaits them on the other side of the vault door.
• Direct or indirect victims of the nuclear war: Super Mutants and Ghouls of varying levels of sentience, some so well attuned to the ever-present radiation that it mends their wounds.
• Unlucky descendants of lucky survivors in the Great War, who've known no life other than survival in the vast Wasteland or in one of its few remaining settlements. 
• Various fusion-powered robots, specialized to perform certain functions and/or repurposed for various Wasteland needs.
• Raiders without allegiance who seek to do nothing but plunder and pillage unfortunate settlers who've managed to scrape a few caps together. 

Crack open a Nuka-Cola (and pocket the bottlecap), check your Geiger counter, load the microfusion cells in your laser pistol and hope there's no Deathclaw around the corner. Because war...

War never changes.