PRANAfilm in Germany pretty famously got in trouble by turning Bram Stoker’s novel Dracula intoi the film Nosferatu without asking permission (or paying royalties). Stoker’s widow Florence sued the pants off them and tried to get all copies of the film destroyed. Fortunately, she didn’t succeed. Since then, filmmakers surreptitiously adapting somebody else’s work for the screen without getting their say-so have done a better job of filing off the serial numbers.
In what follows, it’s therefore not completely clear that the people making the movies were trying to adapt an existing work. In some cases they may just have stumbled across the same idea (as when Gene L. Coon wrote that Star Trek episode with the Gorn, and somebody pointed out that it bore a suspicious resemblance to Fredric Brown’s classic short story Arena, so they bought the rights to the story and changed the title.). The cases are necessarily going to be ambiguous, because when the movies HAVE been stealing things, they want that shield of ambiguity.
The Hidden – I love this low-budget independent film, but the similarities to Hal Clement’s novel Needle are too obvious – One parasite/symbiote chasing a criminal, renegade member of its species on Earth, where they both inhabit human bodies. I can’t believe they didn’t have Clement’s novel in mind.
The Brain Eaters – We know that they were ripping off Robert Heinlein’s The Puppet Masters, because he took them to court, but settled for $5000 and keeping his name off the film.
Panic in Year Zero – another low-budget SF independent film that I love, but many people (including the SF Encyclopedia) are sure that it lifts from Ward Moore’s stories Lot and Lot’s Daughter.
Robinson Crusoe on Mars – another pretty good low-budget effort, but many are convinced that it derives from Rex Gordon’s No Man Friday. (Ironically, there IS a “Friday” in the film)
It Conquered the World – as I pointed out recently on this Board, this low-budget Roger Corman film features a pink lobster-clawed alien who’s really a fungus that collaborates with human sympathizers to take over the world, which makes it suspiciously similar to H.P. Lovecraft’s The Whisperer in Darkness.
Total Recall – the original 1989 Paul Veerhoeven film gives credit to Philip K. Dick’s We can Remember it for you Wholesale, but they exhaust that material in the first 20 minutes or so. I’ve long maintained that the rest of the plot was lifted, without credit, from Robert Sheckley’s The Status Civilization.
The Terminator – I love this film. Cameron admitted that he’d been inspired by things like the works of Harlan Ellison. Ellison thought he’d been too inspired by his Outer Limits scripts Soldier (based on his own short story of that name) and Demon with a Glass Hand and sued, getting post-credits credit.
Sword and the Sorceror – the best parts of this film were the bits they lifted directly from Robert E. Howard’s Conan stories, without giving credit. There’s more Howard in this film than in all three “legitimate” Conan films combined.
Event Horizon – Not a close match, but I swear that the scenes with the Burning Man on the space ship make me wonder if this film didn’t start life as an adaptation of Alfred Bester’s The Stars my Destination/Tyger,tyger. Uncredited, of course
Jupiter Ascending – critics hated this, but I kinda like this entry from the Wachowskis. But I can’t help but wonder if it started out as some kind of adaptation of Cordwainer Smith’s Norstrilia – civilization run by space-going alien super-civilization with system of feudal titles, Everyone fighting for the drug that extends life and gives youth, an Underclass of animal-derived people, and al of Earth being “owned” by a single young person). Again, no credit.
It! The Terror from Beyond Space – I don’t really think that this is a ripoff of A. E. van Vogt’s Black Destroyer, because the only thing the two have in common is the Killer Alien Creature Loose on the Starship. I DO think that Ridley Scott’s Alien is a total ripoff of Jerome Bixby’s It!, though.
Quest of the Delta Knights – I was just watching the MST3K version of this, and you couldn’t miss the similarity to Robert Heinlein’s Citizen of the Galaxy at the beginning. Of course, Heinlein himself was ripping off Rudyard Kipling’s Kim
Honey, I Blew up the Kid – I don’t really think this was ripped off from Kit Reed’s Attack of the Giant Baby, but you do have to admit the similarity of the imagery.