Great movies are supposed to come from great planning, but plenty of classics apparently missed that memo. Some productions started filming without finished scripts, burned through directors, ran wildly over budget, battled impossible weather, or discovered halfway through that their biggest idea simply was not working. Normally, that kind of chaos produces an expensive disaster. Every so often, though, the improvisation and desperate problem-solving somehow make the finished movie better. Limitations force filmmakers to get creative, accidents inspire memorable choices, and productions that seem completely doomed emerge looking strangely confident onscreen. Knowing what happened behind the camera can make the results seem even more miraculous. Here are 15 movies that lucked into being good despite some seriously bad planning and chaos.©IMDbJaws (1975)Steven Spielberg’s mechanical shark malfunctioned so frequently that the production could barely show it as planned. Keeping the shark mostly hidden forced Spielberg to suggest its presence instead, accidentally making the movie far more suspenseful.©IMDbCasablanca (1942)Filming began while the screenplay was still being rewritten, leaving the actors uncertain about where their characters were heading. Ingrid Bergman reportedly did not even know which man Ilsa would end up with while playing the role.©IMDbMad Max: Fury Road (2015)The enormous desert production endured delays, location problems, creative disagreements, and an infamously tense relationship between Tom Hardy and Charlize Theron. Somehow, George Miller assembled the difficult shoot into one of the most acclaimed action movies of its era.©IMDbBack to the Future (1985)Weeks of the movie were filmed with Eric Stoltz as Marty McFly before the filmmakers decided the casting was not working. Michael J. Fox replaced him, forcing the production to reshoot huge amounts of footage while Fox simultaneously worked on Family Ties.©IMDbApocalypse Now (1979)Francis Ford Coppola’s production became almost as chaotic as the war depicted onscreen. Typhoons destroyed sets, Martin Sheen suffered a heart attack, Marlon Brando arrived unprepared, and filming stretched far beyond its original schedule.©IMDbStar Wars (1977)George Lucas faced technical problems, budget pressure, skeptical studio executives, and an edit that initially failed to come together. Extensive restructuring in post-production helped transform a troubled production into a movie that changed Hollywood.©IMDbThe Blair Witch Project (1999)The actors were sent into the woods with limited information and increasingly difficult conditions while filmmakers communicated through hidden instructions. The deliberately chaotic production helped create performances that felt far less controlled than traditional horror acting.©IMDbGladiator (2000)The screenplay was still changing during production, and Russell Crowe later recalled questioning some of the dialogue he was being given. The unexpected death of Oliver Reed before filming was complete also forced the production to improvise around unfinished scenes.©IMDbIron Man (2008)The movie entered production without a completely finished screenplay, leaving the filmmakers and actors to develop significant portions of scenes as they went. Robert Downey Jr.’s improvisational style ultimately became central to Tony Stark’s personality.©IMDbThe Wizard of Oz (1939)The production cycled through directors, rewrites, casting changes, makeup problems, and numerous behind-the-scenes difficulties. Victor Fleming eventually completed most of the film before leaving to take over another troubled production, Gone with the Wind.©IMDbPirates of the Caribbean: The Curse of the Black Pearl (2003)Disney executives were reportedly uncertain about Johnny Depp’s unusual interpretation of Jack Sparrow while the movie was being made. The performance they worried might derail the project instead became its defining feature and launched a massive franchise.©IMDbTitanic (1997)James Cameron’s production ran over schedule and over budget while building enormous sets and attempting technically demanding water sequences. Industry observers openly wondered whether the escalating production might become one of Hollywood’s most expensive failures.©IMDbThe Bourne Identity (2002)The production dealt with script rewrites, reshoots, delays, and disagreements between director Doug Liman and the studio. The messy process nevertheless produced a stripped-down spy thriller whose style influenced action movies for years afterward.©IMDbThe Emperor’s New Groove (2000)Disney originally developed the project as a much more serious musical called Kingdom of the Sun. After years of production trouble, major story changes, and creative upheaval, much of the original concept was discarded and rebuilt as a fast-paced comedy.©IMDbAmerican Graffiti (1973)George Lucas made the movie on a tight budget while the studio remained skeptical about its commercial prospects. Production was rushed and chaotic, but the limitations helped create the loose, lived-in feeling that made the movie a surprise hit.The post 15 Movies That Lucked into Being Good appeared first on Den of Geek.