Movies are often based on comics, books and other varied sources, something we all know far too well. However, some films don’t advertise openly that they’re based on some other product, or at least you need to squint to be able to catch the part where they mention it. If you do some research, you’ll notice that there’s way less original content out there than you might imagine.Granted, it often happens that when a movie initially comes out, it is fairly advertised that it is based on something else. But once a movie’s been out for a few years, audiences tend to forget that part, and just remember the film as the originator of the tale. Here are a few movies that you might not know were adaptations.cnx.cmd.push(function() {cnx({playerId: "106e33c0-3911-473c-b599-b1426db57530",}).render("0270c398a82f44f49c23c16122516796");});IMDbHow to Train Your DragonDreamWorks’ How to Train Your Dragon is loosely based on Cressida Cowell’s children’s book series. The film changed plenty, including Hiccup and Toothless, but Cowell’s Viking world and central idea of befriending dragons provided the foundation.IMDbThe Iron GiantThe Iron Giant began as The Iron Man, Ted Hughes’ 1968 children’s book. Brad Bird’s movie moved the story to Cold War-era America and substantially reinvented it, but the enormous metal visitor remained the story’s central idea.IMDbMen in BlackBefore Will Smith and Tommy Lee Jones battled extraterrestrials, Men in Black existed as a comic created by Lowell Cunningham. The 1997 movie adapted that comic’s secret alien-policing premise, though the film substantially reshaped its characters and story.IMDbRoad to PerditionTom Hanks’ Road to Perdition came from a 1998 graphic novel written by Max Allan Collins and illustrated by Richard Piers Rayner. The source followed an Irish mob enforcer and his son, providing the movie’s crime-family foundation.IMDbStarship TroopersPaul Verhoeven’s Starship Troopers is based on Robert A. Heinlein’s 1959 novel. The movie famously took the material in a satirical direction, while changing major elements including the military structure and omitting Heinlein’s iconic powered armor.IMDbMrs. DoubtfireRobin Williams’ Mrs. Doubtfire was adapted from Anne Fine’s 1987 novel Alias Madame Doubtfire. The film retained the divorced father disguising himself as a female housekeeper, but expanded and reshaped the story substantially for Hollywood comedy.IMDbEdge of TomorrowEdge of Tomorrow, starring Tom Cruise and Emily Blunt, originated with Hiroshi Sakurazaka’s Japanese light novel All You Need Is Kill. The source follows Keiji Kiriya repeatedly dying and reliving the same battlefield, forming the movie’s time-loop premise.IMDbCloserMike Nichols’ Closer wasn’t originally a movie at all. Patrick Marber adapted his own acclaimed 1999 stage play for the 2004 film, retaining the story’s quartet of characters while translating its intensely intimate confrontations from theater to cinema.IMDbVanilla SkyVanilla Sky is actually an English-language remake of Alejandro Amenábar’s 1997 Spanish film Abre los ojos. Cameron Crowe retained the original’s central premise and Penélope Cruz, but reworked the material for an American setting and sensibility.IMDbWantedAngelina Jolie and James McAvoy’s Wanted was loosely adapted from Mark Millar and J.G. Jones’ comic miniseries. The movie retained the comic’s assassin organization and Wesley Gibson, but changed enough of the story that readers might barely recognize it.IMDbKingsman: The Secret ServiceKingsman: The Secret Service began as Mark Millar and Dave Gibbons’ comic The Secret Service. The movie shares its central idea of a young man entering an elite British spy organization, but the filmmakers substantially changed the plot, characters, and tone.IMDbDie HardDie Hard is adapted from Roderick Thorp’s 1979 novel Nothing Lasts Forever, itself a sequel to The Detective. The movie discarded the book’s original characters and connections, transforming its protagonist into John McClane and creating an entirely different franchise.IMDbBlade RunnerBlade Runner draws from Philip K. Dick’s 1968 novel Do Androids Dream of Electric Sheep? The film retains the premise of hunting artificial humans, but its atmosphere, terminology, characters, and philosophical emphasis differ substantially from Dick’s original story.IMDbTotal RecallArnold Schwarzenegger’s Total Recall was also adapted from Philip K. Dick’s 1966 short story We Can Remember It for You Wholesale. The movie greatly expanded the relatively short source, turning its memory-manipulation premise into a sprawling science-fiction action adventure.IMDbMinority ReportSteven Spielberg’s Minority Report originated with, once again, Philip K. Dick’s 1956 story of the same name. The adaptation retains the idea of future crimes being predicted, but Spielberg and screenwriter Scott Frank dramatically expanded the setting, action, characters, and central mystery.The post 15 Movies You Didn’t Know Were Adaptations appeared first on Den of Geek.