Cortosis – What Material Is This and How Does It Work?
Star Wars fans watching The Acolyte who hadn’t read much of the old Legends Expanded Universe books and comics might have been surprised to see The Stranger’s helmet and gauntlets temporarily deactivating lightsaber blades on each touch.
While it was never officially confirmed in the episode, some old book readers might have recognized the telltale signs of cortosis, a type of metal that popped up often in Legends stories (StarWars.com has since confirmed it).
Cortosis was a type of metal/mineral that could absorb energy at a remarkably high rate. When a lightsaber blade came into contact with it, it would short out and deactivate for several seconds before it eventually reactivated, while barely leaving a scratch on the metal itself. Armor laced with cortosis was arguably stronger than Beskar, as not only could it withstand a lightsaber, it would leave its wielder without their primary weapon for crucial seconds.
Interestingly, The Acolyte appears to have added another feature to cortosis — StarWars.com points out that Jedi and other Force wielders are unable to sense people’s thoughts and feelings if they are protected by cortosis, which is hinted at in the show when The Stranger points at his helmet and states that he doesn’t want Sol to read his mind.
Cortosis popped up in multiple places in Star Wars Legends stories, mostly during the Old Republic era and in the Darth Bane novel trilogy, although its first appearance was in the I, Jedi novel set after Return of the Jedi.
Since NEW DAWN began life in the EU era it was natural that the book mined (pun intended) past works for substances. Cortosis came from @MikeStackpole‘s I, JEDI from an idea by Timothy Zahn. Thorlide came from my KOTOR comics. Not sure about baradium; maybe SHADOWS OF THE EMPIRE. https://t.co/EUWi2KOKf1
— John Jackson Miller (@jjmfaraway) June 26, 2024
Wookieepedia points out that the effects of cortosis weapons could be inconsistent in Legends. While cortosis armor and ore would usually deactivate a lightsaber, weapons that had a cortosis weave wouldn’t deactivate a lightsaber blade. It seems that these weapons included just enough cortosis to stop a lightsaber cutting through a sword laced with the metal, but wouldn’t actually short circuit the blade itself. This seems to be the explanation for its use in the Knights of the Old Republic video games, where every sword and vibroblade appears to be laced with cortosis as an in-game explanation as to why the player’s sword doesn’t break every time they come up against a Sith or Dark Jedi.
It got to the point where cortosis was often used as a handy reason why someone with a lightsaber couldn’t simply cut down their enemies with no resistance. If an opponent didn’t wield a lightsaber, they probably used a cortosis blade or had it laced into their armor. It could become a bit of a narrative crutch sometimes, which might be the reason why cortosis has very rarely popped up in the new, current canon.
It’s very rare to see cortosis in current canon, with The Acolyte‘s fifth episode serving as its official introduction into live action. It first popped up in the Star Wars Rebels prequel novel A New Dawn, when Kanan and Hera came up against a cyborg with cortosis weaved into his skin. When Kanan fired a blaster bolt at the man, he was able to absorb the energy and redirect it back at Hera, something that never even happened in Legends.
The only other novel to feature cortosis was Thrawn: Alliances, which saw Thrawn team up with Anakin Skywalker during the Clone Wars to destroy a droid factory producing droids with cortosis-laced armor (as well as clone trooper armor for Order 66). If the factory had been allowed to continue existing, the armor almost certainly would have won the war for the Separatists and exterminated the Jedi.
It also popped up in issues 24-26 and issue 30 of the Doctor Aphra comic back in 2022, when it was revealed that the Ascendant dark side cult had crafted a sword laced with cortosis to fight the Sith. The Tagge Corporation had also been creating a plasma blade that used cortosis somehow, in an effort to replicate a lightsaber without using kyber crystals. Before that, it appeared in the War of the Bounty Hunters – Boushh one-shot comic and the final issue of the Hidden Empire crossover (that was the same sword mentioned earlier) and in the Star Wars: Uprising mobile game.
It will be interesting to see if cortosis and its effects will continue to be seen in The Acolyte, and it would be nice to see it pop up a bit more often in live action now other creators will surely be introduced to it. Hopefully it’s not used too often as a way to “level up” enemies against the Jedi — it’s best used sparingly to make sure writers don’t keep going to that well.
Josh is a huge Star Wars fan, who has spent far too much time wondering if any Star Wars character could defeat Thanos with all the Infinity Stones.
