Dick wrote a number of mainstream literary novels (including the above-mentioned Confessions of a Crap-Artist), most of which have been published posthumously. But the greatest of his fictional works fall within the SF genre, which allowed Dick a conceptual and imaginative freedom that was severely crimped by the strictures of consensual reality favored by the mainstream. Even within the SF genre, Dick was considered something of an odd figure, with his penchant for plots that emphasized metaphysical speculations as opposed to "hard" science predictions. Still, the sheer vividness, dark humor, and textured detail with which Dick rendered his spiraling alternate universes and the oh so human characters who inhabited them won over a sizable number of SF readers. In a writing career that spanned three decades, Dick produced a number of stories and novels that are widely regarded as SF classics; these include Time out of Joint (1959), Martian Time-Slip (1962), The Three Stigmata of Palmer Eldritch (1965), Ubik (1969), A Scanner Darkly (1977), and Valis (1981).

In 1963, Dick was awarded the highest honor that SF has to bestow: the Hugo Award for The Man in the High Castle, a novel that exemplifies Dick's trademark blending of SF plot structure (as to which the number one rule is constantly to amaze the reader) and philosophical mazemaking (with a no-holds-barred skepticism that allowed for all possibilities). Dick was fervent in his view that SF was the genre par excellence for the exploration of new and challenging concepts.

As Dick himself explained in an epistolatory interview (with critic Frank Bertrand) included herein: "Central to SF is the idea as dynamism. Events evolve out of an idea impacting on living creatures and their society. The idea must always be a novelty... . There is SF because the human brain craves sensory and intellectual stimulation before everything else, and the eccentric view provides unlimited stimulation, the eccentric view and the invented world."