Fan theories come in all shapes and sizes, and Star Wars has always had its fair share of interesting speculation. For example, a theory involving two Luke Skywalkers has recently seen a surge of renewed interest, with actor Mark Hamill himself tweeting about it. While Legends canon did have Luke clones, this theory delves into much more unusual concepts than cloning.

The theory's premise relies on the existence of two separate versions of Luke in Star Wars: a "Prime" Luke and a "Bigger" Luke that is physically larger. The Bigger Luke theory indicates something even more sinister: a conspiracy within the Star Wars universe to pass two different Luke Skywalkers off as the same person.

Related: Star Wars: Luke Skywalker Was Shockingly Close to Joining the Empire

The Onscreen Height Differences

Star-Wars-Luke-Han-Leia

The Bigger Luke theory's basis lies in Hamill appearing larger in some shots from the original trilogy than others. There is nothing unusual about this on its own, because film productions sometimes scale an actor’s height back and forth to better fit a scene. This process can involve anything from innovative camera angles and elevated sets to actors wearing shoe lifts to appear taller. In a movie series with performers ranging in height from R2-D2 controller Kenny Baker to Peter Mayhew, who played Chewbacca, minor adjustments to an actor’s eyeline and perceived size would not be unusual. However, Luke's height discrepancies stand out because of their implications on the whole of Star Wars.

The fanbase refers to this diverse collection of theories as "The Canon Luke Hypothesis" because they all provide reasons for a second Luke to exist within the Star Wars canon. Some of the more minute explanations include suggestions like R2-D2 using a holographic projector to make a second Luke appear when necessary. Other fans speculate that Bigger Luke is a subconscious Force projection from Luke Prime in response to Princess Leia asking, “Aren’t you a little short for a Stormtrooper?"

The theories only get wilder as they stray further into speculative territory. One popular idea is that Luke was cloned, and his duplicate is Bigger Luke. While cloning was practiced in the Star Wars universe well before Luke was born, it's anyone's guess as to who would do it and why. Some fans speculate that Uncle Owen or Obi-Wan Kenobi created the Bigger Luke clone to keep Luke Prime safe. Others suspect that R2-D2 could have done so as a part of a long-term mission to preserve the Skywalker line. The Dagobah Elimination Theory suggests that during The Empire Strikes Back, Luke Prime killed Bigger Luke at the Dark Side Cave on Dagobah while Bigger Luke wore a reproduction of Darth Vader's armor. One site extrapolating on this theory claims that it is "one of the most common views held amongst believers in The Canon Luke Hypothesis."

Related: The Mandalorian: Was R2-D2 Lurking on the Planet Corvus?

Two Marks Instead of Two Lukes?

A more grounded alternate hypothesis claims that there aren’t two Lukes, but instead, two different actors playing him. Hamill suffered a motorcycle accident in January 1977, and a few long-distance landspeeder shots were filmed with another actor in his stead. The wampa fight scenes at the beginning of The Empire Strikes Back, for example, were created to explain Hamill’s scars from the accident. The “Hamill theory” goes on to suggest that Lucasfilm used a stand-in actor for far more of the movie than they let on, which would account for the presence of Bigger Luke in shots that Hamill supposedly completed himself. It's also a plausible explanation for why Bigger Luke would appear in Empire or Return of the Jedi, both of which were filmed well after Hamill had recovered.

The Canon Luke Hypothesis is Star Wars’ own “Paul is dead.” It’s quite a reach to make many of these ideas fit into the canon, and some are a little more tongue-in-cheek than others. Still, they present a plethora of creative possibilities for the Star Wars universe with far-reaching implications.

Keep Reading: Star Wars: Darth Vader's Other 'Son' Was a Twisted Luke Skywalker