Plot Armor does what now?

I know it's kind of a trope, and people are using it less now, but I still see Plot Armor come up every now and then so I thought I'd put my two cents in on the subject.

When a character has Plot Armor it's generally taken that they are invaluable to the story and thus we can feel safe in the assumption that they will be around until the end. I would argue that that is largely true-- with one caveat: Plot Armor makes one invaluable to the story but beatings still apply.

I know the story I'm about to mention isn't always very popular, but it was while reading Fallout Equestria: Project Horizons that I first articulated the principal I'm referring to. The story has more than a few flaws, including its tendency to be downright nasty to its characters, but that was what really cemented this concept in my mind. The lead character in FE:PH gets shot, stabbed, burned, blown up, tortured, mentally screwed, loses limbs to tumors, blinded, and killed among a host of other and darker things. I'm not saying you should read the story, but I am saying that THIS is the truest incarnation of Plot Armor. It's not a physical armor that protects a character from swords or mental trauma. It's a promise from the writer to the reader that, come what may, 'this character is sticking around.'

Now you might think that think this is an extreme example. That this never happens in popular stories because people wouldn't like them. Okay then, fine. Lets have an example everyone can relate to. How about Star Wars Episode IV: A New Hope? It would be easy to say that Luke of all people had plot armor, that we couldn't lose him because otherwise the whole story would fail, but let's take one more step sideways.

I argue that Ben Kenobi had Plot Armor, and I think it's a particularly good example because he straight up died. Darth Vader Killed him and his Plot-Armor-Infused-Robes wouldn't let him rest. He lost his entire body and still had to come back to guide Luke. Without Ben Kenobi, Luke would have been killed trying to stop the Death Star, he never would have traveled to Dagobah, and he would have ended up with inbred whiny children provided he survived long enough. Ben Kenobie is the real hero of Star Wars.

But back to my point. Characters are often saddled with a set of Plot Armor that keeps them safe and also restricts what the author can do to them. Without suffering and being broken down, even a small bit, what growth the characters do go through often seem superficial. I'm not saying that everyone should go around lopping off limbs, but there was more significance to Luke's lost hand in Episode VII then just the physical lack. The emotional scars are what changed his character in the end.

So go out and let characters get hurt. Really hurt. Let it change them on a fundamental level. Don't ever let them forget it. Because I think it's that allowance that gives them room to grow stronger from the ashes.