Ah I had no idea, I just assumed it was directly from the comic books! I've been reading the walking dead comics for a long while but never got into the DC comics and wanted to try reading something different. I'm a newbie!
^ a huge thank you to everyone for replaying!! All of that was really super helpful and I'll start out with the dark night and death of superman then go from there
Many thanks again!
-Katie

Those are correct and they are both "events" (Dark Knight Returns is actually a mini series so you can find that easily enough) and if you google "Death of Superman" you should get a pretty comprehensive listing of the various comics involved.

The two main arcs that it's based on are The Dark Knight Returns and The Death of Superman. You should be able to find them pretty easily online or in a comics shop.
If you can't defend a movie without bashing another, you will be put on ignore. No exceptions.

It's not exactly based on a comicbook storyline, but if you'd like to know more about the characters, the DCEU characters are heavily based on their New 52 versions. For Batman you should also read the The Dark Knight Returns stories from Miller and for Superman, you should probably read the Death of Superman story as well. Other than that, you could also read the tie-in comics for Man of Steel, BvS and SS. The tie-in comic for JL will drop around 1-2 months before release so keep an eye out for that as well. There is an animated JL movie based on the New 52 version;
http://www.imdb.com/board/13060952/
, check it out.
I'm the thing that keeps you up at night, the evil that haunts every dark corner of your mind

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