The very first character shown in Star Wars: A New Hope is none other than the R2-D2. His early appearance and importance throughout the groundbreaking film clearly showed how important the little droid was going to be to any follow up Star Wars movies. In fact, one fan theory that circulated after A New Hope’s release theorized that R2-D2 might be even more important than fans thought. It stated that R2-D2 was actually Luke’s father.
According to this wild fan theory, R2-D2 was not a droid, but a cyborg. In other words, he was part droid and part human, with the human part being whatever remained of Luke’s father after his duel with Darth Vader. This meant that when Obi-Wan told Luke that Vader had murdered his father, he was telling the truth from Vader’s perspective. The Sith Lord thought that he killed Skywalker, but in reality, enough of the man’s brain had survived to be preserved with the help of robotics.
The theory was clearly disproven by The Empire Strikes Back, and no one really gave it much credence after Vader’s shocking reveal. Not to mention, a droid fathering a child sounds like a ridiculous premise. Retrospectively, though, with only A New Hope as evidence, the theory could have made sense in a weird, Star Wars type of way.
At one point in the writing process, Luke Skywalker’s father was actually alive and in the story. However, somewhere down the line, that idea was discarded, and to all appearances, Luke was left as an orphan living with his aunt and uncle. By the time A New Hope was released in theaters, Luke’s father was only mentioned twice in the film: once by Uncle Owen, and once by Obi-Wan Kenobi.
Neither of these characters told Luke the entire truth about his father. Uncle Owen told the boy that his father had been a navigator on a Spice freighter, while Obi-Wan told him that he had been a great pilot and warrior. Both told Luke that his father was dead, although they did so for very different reasons. The bottom line was that the identity of Luke’s father was left ambiguous, and the conflicting stories that were told about him got people thinking about what the full truth might be. So in response to these circulating questions, some fans speculated that Luke’s father was not completely dead and, in fact, could even be the droid who'd been at his side the entire time.
The proof was simple, but circumstantial at best. It could've shown why R2-D2 was so important to the Rebel Alliance. If Skywalker was such a great Jedi warrior, then he would have been helpful to the Rebels as they fought against Vader’s Empire. It also helped to explain why Luke was able to progress through his initial Jedi training so fast. He quickly learned how to deflect blaster bolts with his lightsaber and was later able to communicate with a deceased Obi-Wan, even though he had only been using the Force for a few days. If Anakin was covertly hiding inside of R2-D2, it meant that he could have been helping his son all along, even though Luke did not realize it.
Although the theory could have worked from a bird’s eye view, there wasn’t really anything in Star Wars: A New Hope to point in its direction, and it’s a good thing that it was wrong. The big reveal at the end of The Empire Strikes Back just wouldn’t have been the same if it had been R2-D2 beeping that he was Luke’s father.