C-3PO, better known as “Threepio” or “Goldenrod,” is a protocol droid, designed to employ proper etiquette at all times. The uptight dork of Star Wars series, C-3PO is fluent in over seven million forms of communication, and he has probably complained in at least half of them. People rarely consider him one of the best Star Wars characters. See, although he's frequently at the center of events with galactic import, Threepio does his best to avoid conflict. Despite his pacifist ways, however, the Star Wars canon is rife with examples of C-3PO being cool. No, seriously. In the films, the Star Wars Legends, and the comics, Threepio has managed to make his mark on the galaxy far, far away in more ways than he even realizes.
Those who know the stiff-walking droid best would probably use the same sorts of words to describe him: fussy, condescending, long-winded, aggressively annoying. That sort of thing. "Brave" and "heroic" are two words that are almost never used in relation to old Goldenrod, but that might need to change. As it turns out, in C-3PO’s century-long fictional life, he’s proven himself to be a true badass on more than a few occasions.
C-3PO doesn’t usually get a lot of respect, but that changed the moment he stepped foot on the moon of Endor in The Return of the Jedi. The Ewok race are not particularly welcoming to strangers, as evidenced by their desire to eat Han Solo and his friends, but they made a real exception for C-3PO.
The Ewoks believed Threepio to be a golden god, both due to his appearance and his remarkable ability to communicate with them. They built him a throne, and even listened to his anti-cannibalistic suggestions. “Jub jub,” indeed!
There was a lot of buzz regarding C-3PO’s appearance in The Force Awakens. His presence in the film was, of course, expected, but fans were shocked to see that he was sporting a new, red arm. Threepio himself mentions the colorful new limb, which prompted many to speculate that there had to be a good story behind it. It turns out there there totally was.
Marvel published a C-3PO one-shot comic that supplied the red arm’s origin story, and it is tragic. During a post-Return of the Jedi mission, C-3PO befriended a red droid who ended up sacrificing himself so that Threepio could seek shelter from super acidic rain. All that was left of the brave robot was his left arm, and since Threepio had recently lost his (it was a whole thing, don't worry about it), he took on his friend’s limb as a functional memento.
In the culminating episode of the Skywalker saga, C-3PO makes a profound sacrifice to make sure the Resistance can get what it needs to find Exegol and stop the Final Order from destroying the galaxy. Threepio is nothing if not a strict rule follower, which proves a frustrating hurdle with the discovery of Sith loyalist Ochi's engraved dagger on Pasaana. As a protocol droid versed in more than 6 million forms of communication, C-3PO can translate the message on the blade, but his programming as an upstanding member of society prevents him from speaking it.
With the Final Order mere hours away from sending out their fleet of Star Destroyers, Rey, Finn, Poe, BB-8, and Threepio head to Kajimi where Babu Frik, a droidsmith from Poe's pre-Resistance days, can unlock the translated text. Resetting C-3PO's programming to make him reveal the message comes with a gutting caveat: the droid will lose all of his memories in the process. With little delay, Threepio decides to make that sacrifice since he knows there's no chance for the Resistance to succeed without it. Though the always reliable R2-D2 has a copy of the protocol droid's memory banks saved, C-3PO still made the decision under the assumption that he wouldn't come back the same.
For most, The Empire Strikes Back is the pinnacle of the Star Wars saga. For C-3PO specifically, it was his own shining moment. Much of the drama in Empire comes when our heroes fall into a trap laid by Darth Vader and his cronies at Cloud City. Lando Calrissian sold Han Solo and friends out, hiding the Imperial presence on his planet, but the ruse was almost thwarted by C-3PO.
Threepio walked in on a few Stormtroopers hiding out in a supply closet, discovering a secret that no other protagonist was able to. Unfortunately, he was blasted to bits for his efforts and had to be carried around by Chewbacca for a little while.