8 Incredible Ways Movie Spoilers Were Kept Secret

The fact that Darth Vader is Luke Skywalker's father is now common knowledge, but when The Empire Strikes Back first came out in 1980, it was one of the most surprising revelations in cinematic history - if not the most.

The original Star Wars film wasn't anticipated at all, but for its sequel, the hype was so high that George Lucas went to extreme lengths to preserve the film's biggest surprise: when the day came to shoot the now-famous scene, only three people across the entire production had any idea what was actually going on.

The way the scene was filmed resulted in exactly what you see onscreen, but with one big difference; on the day, the actor playing Vader said "Obi-Wan killed your father" instead of "I am your father." The proper line was dubbed in during post-production, and the only people who knew this was the case were Lucas, Mark Hamill, and Empire's director, Irvin Kershner.

Before shooting the scene Kershner took Hamill to one side and told him the truth, mentioning that only he and Lucas knew - so if the twist leaked, they'd know Hamill was to blame.

And the rest is history. This whole ruse was successful, and audiences the world over sat completely shell-shocked as the reveal of Luke's true parentage unfolded before their very eyes.