10 Shocking Comics Events That Changed Characters Forever
4. The United States Passes The Superhero Registration Act - Civil War
The big two are downright obsessed with their status quos, and even when they DO shake things up, they often choose the stupidest hills to die on (One More Day, the death of Lian Harper etc.).
However, though the original Civil War was definitely an example of the latter - it being a really, REALLY bad event comic in itself - what came of it was one of the most interesting changes to the Marvel status quo: the Superhero Registration Act.
When a group of reckless superheroes cause an explosion that wipes an elementary school full of children off the map, the United States government decides that enough is enough. Superheroes need to be held responsible for the damage caused by their actions, let their identities be known and open to scrutiny like any public official, or stand down/turn themselves in. This being a Mark Millar comic, you can guess how things go from there.
But despite the divisive nature of the story itself, Marvel stuck to its guns on the Registration Act for an admirably long time. And even with it gone, its ghost still haunts the Marvel universe with more recent events like the creation of C.R.A.D.L.E.