The vast multiverse conceived by Stephen King across the Dark Tower series, encompassing not only Roland Deschain's dying world but the many parallel universes connected by the Dark Tower at the centre of existence. All-World is the term Roland's people use for their own reality - a world that has moved on, its technology failing, its geography distorted, its population dwindling - but the universe extends far beyond it to include versions of our own world and countless others. The Tower itself is the linchpin of all realities, and its threatened collapse is the central concern of the entire sequence.