It's not a spoiler to say that a bunch of lightsabers fly around in Star Wars: The Last Jedi. The trailers for the film were full of them, and the weapons are pretty much a staple of any installment of the franchise. But after seeing both Luke Skywalker and Rey use their lightsabers in The Last Jedi, fans may be a little confused about the color of Luke's lightsaber — especially those who haven't seen the original trilogy in a while.
In Star Wars: The Force Awakens, Rey finds Luke's lightsaber at Maz Kanata's cantina and uses it a few times in the film, where it's shown to have a blue blade. In the final scene, Rey finally finds Luke and presents him with the lightsaber.
Cut to Star Wars: The Last Jedi, which picks up right where its predecessor left off. In an unexpectedly light moment, Luke responds to Rey's intense, emotional offering by taking the lightsaber and throwing it down the cliff behind them. Obviously, that's not the end of such an important piece of the Star Wars mythology, so Rey retrieves the lightsaber and uses it to train throughout The Last Jedi.
Here, Rey's inherited lightsaber is blue once again, but it is not these scenes that can cause confusion for new or rusty fans — it's flashbacks.
In The Last Jedi, we see into Kylo Ren's past, when he was a young student training under Luke and still going by his real name, Ben Solo. Both he and Luke recall a pivotal confrontation, during which we see Luke using a green lightsaber. But if Rey found and has been using Luke's old lightsaber, why is it blue?
This is where you have to think back to the original Star Wars trilogy. In Episode IV: A New Hope and Episode V: The Empire Strikes Back, Luke uses a blue lightsaber, the very one that Rey has been using in this latest trilogy. But Luke did not create this saber himself — it belonged to his father, Anakin Skywalker, the future (37-year-old spoiler alert) Darth Vader.
In the most iconic scene in Star Wars — and perhaps cinematic — history, Luke battles Darth Vader in The Empire Strikes Back and in the process, loses both his right hand and his lightsaber.
That was the last we saw of the blue Saber that had been passed from one Skywalker to another... until The Force Awakens.
You see, once Luke lost that weapon, he built his own lightsaber, one with a green blade. That is what he uses in Episode VI: Return of the Jedi, the flashbacks to his confrontation with Ben Solo, and the present timeline of The Last Jedi. The blue lightsaber that Rey got from Maz and has been using ever since hadn't belonged to Luke in many, many years.
Once you recall those plot points, it actually explains other parts of the new trilogy. Not only does it resolve why Luke is seen using a green lightsaber when the one Rey found is blue, but it also forges a connection between Kylo and the blue saber.
Since the blue lightsaber was passed down (via Obi-Wan Kenobi) from Anakin Skywalker, it's a sort of family heirloom for Kylo Ren. The blue lightsaber belonged to his uncle, and before that, the grandfather he's been trying so hard to emulate. Now you can see why Kylo was so shocked that the saber flew into Rey's hand in their climactic battle in The Force Awakens, rather than his own — and why he tries to take it from her so many times in both films.
So if you thought Luke using both a green and blue lightsaber was some kind of plot hole, you seriously underestimated the people behind Star Wars. Every detail of the franchise has a rich history, and something as simple as a color can connect characters across generations.