DC Comics didn't invent event comics, but it can be argued that they perfected them. Crisis On Infinite Earths was DC's twelve-issue thesis on what an event comic can be and DC has followed its example for years now. What many modern fans don't realize is just how much work went into Crisis. The writer/artist team of Marv Wolfman and George Pérez had to plan for years in order to make the series work, sprinkling clues throughout DC's lineup until the book's big debut in 1985. This set a precedent for how to do an event comic that DC would remember years later when it was planning Crisis's sequel.
Source：https://www.cbr.com/infinite-crisis-dc-marvel-comics-last-great-event-hype/
