This page is best read with the Alternate Timeline in a tab beside it, as it offers oversight.
The Alternate Lore differs from the main ATF Universe due to the obvious fact that although the premises are the same, the universes are starkly different.
It's the year 2045. New York. Humanity has been driven underground in this area, and nuclear winter rages on above. Life in the tunnels is hard, although familiar. In 1992, the Civilian Defense Front, a post-war revival of Civil Defense, built the underground town known as Central Town. In 2019, remnants of the United States Civilization Preservation Force, a post-war all-encompassing term for the former military, built a high-tech base on the surface, now inhabited by nothing but raiders. Further to be found is the USS Ascending, a battleship good as ready to join the Seventeenth Fleet in Vietnam, which she unfortunately never did. Rusting away now in an old abandoned covered shipyard, she remains a stark reminder of what violence did to the world.
The Deep Winter universe and the Main ATF Universe share lore with each other, although for all intents and purposes, Deep Winter still takes place in an alternate universe because the locations and events that take place in game cannot exist both here and in After the Flash: Deep Six. Southside is just a small rural town in Georgia and Fort Shad is just an average US Military installation.