Pacific Rim had drift compatibility.
Elfquest had recognition.
His Dark Materials had daemons.

What are other media that have a Thing like that - a quirk in the worldbuilding that's at least kinda unique and used a lot in the story?

@Anke I would say Pern and its telepathic dragon bonds but I don't think it counts as "kind of unique" anymore, what with effectively spawning an entire genre. >.>

@senbonzakura I guess a Trope Codifier like that still deserves mention, thank you!

Hm, then...
Narnia for "kids summoned to a fantasy world to fix stuff"?

@Anke that's a great question, I have to go check some publication dates before I can give an opinion about that
@Anke The Wizard of Oz predates The Lion, The Witch and The Wardrobe by fifty years, so while Narnia is possibly the most continuingly popular and well-known historic example of the trope, I don't think it gets the credit this time xD
@senbonzakura Oh. I thought Dorothy got to Oz by accident, not because she was summoned or destined or something.
Ehwell.
I'm not even sure about Narnia, never read those.
Thank you!
@Anke technically, the Pevensies also wandered into Narnia on accident, there's just some elements of predestination involved
@senbonzakura Tangent: I just know I really liked Magic Knight Rayearth, and afterwards read somewhere that it was a deconstruction of a genre of stories of kids from the real world summoned to a fantasy world as Champion Heroes that I had never noticed before.
*rambles*
@Anke oh yeah! All of Clamp's stuff is kind of subversive/deconstructive like that
@Anke CLAMP stories are all pretty good but uhhh don't read Chobits, you won't like it >.>

Card Captor Sakura is good, and xxxHolic is amazing but you really have to read Tsubasa along with it to fully understand it.
@senbonzakura Card Captor Sakura was cute, I really love Wish!
I read the beginning of Chobits because it was in a German manga anthology magazine I read, but yeah, not my kind of thing. I've got part of xxxHolic and like it a lot (and the art is so pretty), and Tsubasa, too, but I kinda stopped following the two of them and never picked it up again.
Does xxxHolic stay at least kinda episodic, or does it get sucked into one big pot as it goes on?