Second Variety (1953)

What It Was: A short story about the aftermath of a nuclear war between the United Nations and the Soviet Union that has turned Earth into a post-apocalyptic wasteland populated by self-replicating, self-repairing robots called "claws," which evolved to disguise themselves as humans so well that even they are unaware of their true nature. It starred RoboCop himself, Peter Weller.

What It Became: The 1995 movie Screamers drops the real-world setting, and turns the story into a pretty generic sci-fi actioner.

Paycheck (1953)

What It Was: A short story about an engineer who, after accepting a job that he wouldn't remember due to an agreed-upon memory wipe upon completion, wakes up to find that he's not been paid, but is in possession of a random collection of objects that act as clues to what happened — namely, that he has created an object so powerful that it could overthrow the government.

What It Became: At first, 2003's Paycheck seems to be faithful to the source material, with Ben Affleck playing an engineer who finds himself memory wiped and in the possession of a number of random objects — but the resolution of the story is entirely different, not only in tone (It's far more action-packed), but in the object that the engineer created, which in the movie is tellingly the very object used as a red herring in the original story.

Adjustment Team (1954)

What It Was: A short story in which a corporate office struggles to explain why a real estate salesman was able to temporarily step outside reality as it was being corrected by the people in charge of such things.

What It Became: Matt Damon's 2011 The Adjustment Bureau is more a riff on the idea of the existence of the Adjustment Team than an adaptation, bringing in all-new characters and an entirely different plot.

The Minority Report (1956)

What It Was: A short story in which the head of the "Precrime" division of the authorities is framed by a conspiracy attempting to usurp the department for its own ends. In the process of escaping arrest, it's revealed that the three mutants responsible for predicting the future are instead viewing alternate realities, but their prediction ultimately comes true as the protagonist is forced to commit murder and is exiled from Earth.

What It Became: Much like Payback, Minority Report goes from what seems like a faithful adaptation into something ultimately less interesting and more action-oriented -- it became a 2002 movie that starred Tom Cruise.

The Man in The High Castle (1962)

What It Was: A novel telling of an alternate history in which the Axis powers won World War II, resulting in a United States torn into pieces and ruled by Japan and Germany, respectively. The title refers to Hawthorne Abendsen, the author of a book within the book in which the Allies won the war.

What It Became: Greenlit as a series for Amazon earlier this year, The Man in The High Castle is — judging by the pilot episode — remarkably faithful to the original book.

We Can Remember It For You Wholesale (1966)

What It Was: A short story about an unassuming worker who, unable to afford a trip to Mars, buys a fake memory of such a trip instead — only to discover before he's received it that he actually did visit the planet as a government assassin. In a final twist to the story, the false memory the authorities choose to replace his impulse to visit with is also revealed to be true, and he saved the world from an alien invasion when he was a child.

What It Became: This is the story that formed the basis of Total Recall, which diverts pretty drastically from the original both in terms of plot and by pretending that Arnold could ever pass for an unassuming worker drone.

Do Androids Dream of Electric Sheep? (1968)

What It Was: A novel in which Rick Deckard, bounty hunter, has to retire six androids who are almost entirely human, with the exception of their inability to feel empathy.

What It Became: 1982's Blade Runner may be the best of all Dick adaptations, remaining faithful to the spirit of the novel as much as the plot (which is, in itself, remarkably faithful). Plus, of course, Harrison Ford and Ridley Scott in their prime, which is hard to argue with.

Radio Free Albemuth (1976)

What It Was: A posthumous novel dealing with semi-autobiographical themes concerning Dick's political and social beliefs, with a far-right president using a fictional organization as an excuse to erode civil liberties, while a real resistance movement organizes with the assistance of a super-intelligent satellite called VALIS.

What It Became: The 2014 movie version of Radio Free Albemuth is betrayed as much by its fidelity to the paranoid source material as it is its low budget, as the trailer below makes clear.

A Scanner Darkly (1977)

What It Was: Another semi-autobiographical latter novel that focuses on Dick's paranoia and drug use, with an undercover police agent becoming addicted to "Substance D," which leads to his being placed in rehab — where he discovers that he is once again part of an undercover operation to discover who or what is behind the rehab clinic.

What It Became: Arguably the most faithful of all PKD adaptations in terms of plot, 2006's animated A Scanner Darkly saw Richard Linklater assemble an impressive cast — including Keanu Reeves, Robert Downey Jr. and Woody Harrelson — to try and make sense of the constantly unfurling plot.