This flexibility allowed artists to depict a world with layers of history and culture on both sides of the timeline's divergence, spanning the generations in both directions from the Great War. The variation in advancement is depicted also throughout the development of weapons, robotics, and engines. Technology developed unevenly in the alternate universe, advanced in some ways and primitive in others, with advancements from real world history having never occurred or if similar, developed much differently. Developers intended for the setting to maintain the dark atmosphere of 1950's apocalyptic prediction, balanced with humor. ДЄs opposed to purely 'fantastical sci-fi designs,' developers considered how industrial and product design would have evolved in the alternate universe. of the 1940s and 1950s also inspired some of the artists, including vehicle design, signage, architecture, and art. The retro-futuristic, 'golden era of science fiction' art style is predominant, but a variety of inspirations were utilized across the board to appeal to a wide audience. ДЄrtists used the divergent timeline as inspiration to maintain a mix of vintage, familiar, modern, and futuristic aspects throughout the game world, and developers were intentional in featuring fictional aspects and real world equivalents appearing both before and after the timeline diverges. For the alterative timeline's impact on environmental storytelling, many objects were created to look familiar to what exists in the real world and others are developed as those from the future.

The environment of the game world after the Fallout timeline diverged provided artists a blank slate to work with in terms of designing their futuristic version of modern day. Information is relayed via gameplay regarding years preceding, stretching back hundreds of years before the Great War event, in various locations across the former United States. To date, the chronological order of Fallout gameplay first begins in 2102 and stretches to 2287. This fork led to a world where technology progressed quickly while maintaining the cultural norms of the mid-century. With the goal of exploring ideas revolving around a futuristic, post-nuclear world, the game setting exists in a timeline that diverged after World War II.

The franchise's timeline stretches from pre-War years, to the 'future of the fifties,' to the decades following the destruction of the earth by nuclear war.

Map of the fallout world