Fallout: Resource Wars is a hypothetical Fallout spin-off mentioned several times by J.E. Sawyer as something he'd like to make.
It would be a game set in the Fallout world's Europe during the resource wars that took place there around the 2060s. Focused on team-based multiplayer, The gameplay could be a blend of Motocross Madness pacing, Battlefield: 1942 foot and vehicle combat, and slightly longer-than-CS duration rounds. Add in a salvaging elements so you can either repair or strip down damaged vehicles/weapons and use them in the next round.
The plot would involve crew of soldiers from the Royal Armored Corps that got stranded in war-torn anarchistic northern Italy and had to fight their way to the English Channel in a bunch of quickly degrading vehicles, scavenging replacements, fuel, and weapons as they go.