Skip the soda this time around, friends: “Avengers: Endgame” will run past the three-hour mark, making the final installment in this era of the Marvel Cinematic Universe longer than each of the 21 films that precede it. That’s a whole lot of superhero sparring and interplanetary warfare to keep up with, given that “Endgame” combines nine franchises and more than 30 major characters — all of which began more than a decade ago with 2008’s “Iron Man.” Retaining that much information would be a superhuman ability in itself.

But don’t worry. We created a guide to all the important happenings leading up to “Endgame,” complete with a list of the characters involved in each one. It’ll have you ready to watch the movie in a snap. (Too soon?)