As comic book movies become increasingly packed with more characters in order to build out the shared universes in which they take place, it is an increasingly difficult task for the movies' writers to put together a coherent and satisfying story. Judging by the positive reviews, the writers of Captain America: Civil War have done just that.

The negative critical reaction to Batman V Superman: Dawn of Justice and the negative reviews that have been coming in so far for X-Men: Apocalypse are two prime example of how universe-building ambition can hurt a film. In both cases, critics have slammed the movies for sacrificing coherent plots for the sake of stuffing in as many superheroes as possible. With Warner Bros. and 20th Century Fox faltering in the face of their expanding cinematic universes, how has Marvel kept from doing the same?

Civil War writers Christopher Markus and Stephen McFeely spoke to The Verge about the process of writing the third Captain America movie, and in doing so shed some light on just how much work went into assessing the needs of the MCU into their script, as well as the needs of the sizable cast of actors involved. According to Markus, collaboration is key, as is a whole lot of rewriting:

"It’s a problem we will continue to have, because there’s usually three [Marvel films] going on at any one time, and it seems like we’re writing the movies where they all come together. So we do check in a lot with other franchises and say, 'Hey, is there a draft, or what are you thinking?' It’s not the case where we just hide in a room and crank something out."

It's not enough to just fit the characters into the movie, though; they have to have a reason to be there. McFeely spoke to how they addressed that with their writing:

"It was also very important that we had a central question, a central spine that every character was operating off of. So they weren’t just off spinning in their own orbit. It was, 'Everyone just enters the movie where the story requires them to.' So that it is not a free-for-all."

Captain America Civil War - Team Iron Man

With a large roster of big-name actors like those in Civil War, there is also the question of working around their schedules. McFeely says that Marvel kept them in the loop as far as when various actors were available, and they would write accordingly:

"Sometimes Marvel will say, 'Hey, odds are we’re going to have this actor for this period of time, so probably not in every scene of the movie, keep that in mind when you’re writing it.' That certainly happens sometimes."

One of the biggest questions when Markus and McFeely were writing the script was whether or not they were going to get to use Spider-Man. The answer to that question changed at various points in the writing process, and the script changed accordingly. According to Markus, one character in particular benefited from the resulting rewrites, and that was Black Panther:

"He was in and out. There had been an early suggestion that it might happen, then it seemed to go away, and then really quite late in the process, Kevin came back in the room and said, 'Guess what?' And when [Spider-Man] was first around, we worked out a way to use him, and when we went away, we kind of filled some of that space with Black Panther. Originally T’Challa was in the movie, but we weren’t sure we wanted to go all the way to Black Panther in the costume. When Spider-Man dropped out, we brought [Black Panther] forward, and then it all paid off, because we got an extra hero out of it. When Spider-Man came back, we kept Panther where he was, because we liked it."

With so many variables to take into consideration, Markus and McFeely certainly had a difficult task in writing the screenplay for Civil War. The end result, however, is proof that Marvel chose well when it gave them the assignment. With the upcoming pair of Avengers: Infinity War movies having an even bigger roster of characters in the mix, time will tell whether Marvel's creative team can pull them all together into another critical and box office success or if the movies will finally buckle under their own weight.

Captain America: Civil War is in theaters now. Doctor Strange opens November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man: Homecoming – July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel– March 8, 2019; Avengers: Infinity War Part 2– May 3, 2019; and as-yet untitled Marvel movies on July 12, 2019, and on May 1, July 10, and November 6 in 2020.

Source: The Verge