In the Star Wars series, losing a hand is pretty much a rite of passage. As a result, Luke's dismembered hand doesn't just hold symbolic value within this film, but also within the series as a whole. Sometimes, guys, a hand is more (or should we say less?) than just a hand.
Luke's hand gets cut off at the tail end of his duel with Vader. In fact, it happens right before Vader's revelation that he's Luke's father. By looking at these two events together, we see that losing a hand represents Luke's feelings of powerlessness, not just in terms of Vader's clearly superior skills, but also in reaction to this shocking turn of events.
As it happens, Luke isn't the only character in the Star Wars series to lose a few digits. Just check the list if you don't believe us:
- Count Dooku cuts off Anakin's arm in Attack of the Clones.
- Obi-Wan cuts off Anakin's other arm in Revenge of the Sith. Oh yeah, and his legs too.
- Obi-Wan slices off a dude's arm in Mos Eisley in A New Hope.
- Luke doesn't just lose a hand in The Empire Strikes Back—he slices off a wampa's arm in the opening scene.
- Luke cuts off one of Vader/Anakin's artificial hands in Return of the Jedi.
Those are just the notable hand-losses. While you might chalk this up to the reality of film-making—after all, nothing's an easier visual for the power of a lightsaber than a severed arm—we think it's clearly an important symbol in the Star Wars series. After all, we're used to thinking of "hands" as synonymous with "utility"—just think of the nautical expression "all hands on deck," the adjective "handy," or the idea that someone could be your "right hand man." If hands = utility, then lack of hands = lack of utility.
Interestingly, the movie ends with Luke's hand being replaced with an artificial replica. This has a few different symbolic meanings. First, it represents hope: It shows that our heroes have re-built themselves after the painful events of the film.
It also implies something darker: After all, Anakin Skywalker (who became Vader) also had his hands replaced with artificial ones. While this second interpretation obviously didn't exist until the release of the prequel trilogy roughly twenty years after the release of The Empire Strikes Back, it provides a darker take on an otherwise hopeful image.