UPDATE: Summer 2013 has many budget busting blockbusters. But also problems that have plagued some during pre-production, filming, and post-production. Not since John Carter and Battleship has a big-budget movie received more advance negative press for its production woes than World War Z, the Marc Forster-directed adaptation of the Max Brooks zombie-apocalypse novel that stars and is produced by Brad Pitt. I was shown the movie, but not in its 3D format, weeks before its June 21 release. And each time the response from industry insiders was a version of, “Well, just how bad is it?” Paramount with these select screenings has just begun the daunting campaign of rehabilitating the film’s battered image. According to Vice Chairman Rob Moore, the studio spent $15M-$20M and 25 shooting days to make WWZ significantly better. Yet the reward has been worse advance buzz than if Paramount had kept its wallet shut and quietly released the inferior original. I don’t know if I would have penned this post had I hated the movie, but I consider myself a connoisseur of zombie fare, and this stacks up very favorably. I’m no reviewer, but I can honestly say that WWZ is better than good; try a rocking, smart, pulse-pounding big-scale pandemic with raging zombies, palpable tension, and the kind of hero star turn Pitt hasn’t performed in a long time.

You know things are bad when your star mouths off about a troubled film before it even opens. His complaints well into production were made to fill-in fixer Damon Lindelof who blurted them out in turn. Scripting issues crippled the globetrotting zombie pic from the get-go. J. Michael Straczynski’s first script was scrapped. Matthew Carnahan’s subsequent version deviated from the source novel by Max Brooks. Fans were alarmed at the prospective story changes. Then filming got underway for director Marc Forster before an ending was set – and Pitt wound up hating what was shot, preferring the project’s early geopolitical bent to the action thriller slant. The film’s initial ending was abrupt and incoherent, Lindelof told Vanity Fair, and an initial studio screening supposedly left suits in shock. “It was like, ‘Wow, the ending of our movie doesn’t work,” publicly admitted Paramount President of Production Marc Evans. “I believed in that moment we needed to reshoot the movie.” So how many hot screenwriters did it take to finish a zombie movie? Paramount turned to Lindelof to fix the pic, but the job was so big he brought in Drew Goddard. Christopher McQuarrie was tapped for even more re-writes. Reshoots skyrocketed the budget to a reported $200M, though Paramount insists they contained it. Already filmed scenes set in Russia and Budapest as well as a battle scene were chopped as crew shot 40 additional minutes for a new conclusion with reshoots that went on for a reported 7 weeks. Meanwhile a budgeting nightmare unfolded when crew wrapping the Malta set discovered millions in unpaid purchase orders forgotten in a drawer. Given the behind-the-scenes mayhem, negative early fan reactions to World War Z‘s fast-moving CG zombie swarms were the least of Paramount’s worries.

That solidly detailed Vanity Fair article created major blowback this month. It grew worse after a widely circulated flop prognostication by Wall Street analyst Doug Creutz of Cowen and Company (even though he hadn’t seen the film). “In the Vanity Fair article, we were forthcoming about the production and creative problems and how we solved them and ended up with a movie that plays great and is likely to be a global hit,” Moore told me. “The thing that really led to more negative stories was the insanity of this Cowen and Company analyst report, written by a guy who hadn’t seen the movie, the footage we showed at ShoWest, or gotten any pre-summer tracking. He just comes off the mountain top to make a prediction based on nothing, and because he’s got the letters CFA after his name, people think he must know what he is talking about, which is preposterous.”

Moore told me that chasing a fix on WWZ was the ballsiest bet like this made since he has been at Paramount. “It was no question one of the toughest decisions we’ve made as a group, but knowing what we know now, it was absolutely the right decision,” he said. He figures the release delay and extra work that went into G.I. Joe led to $100 million in extra ticket sales worldwide, and he believes WWZ will deliver an even bigger payoff. It would just be nice to see a little more understanding among the media and Wall Street analysts, to recognize that just because a film has problems during the process of production, that doesn’t mean it’s doomed.

“When you draw attention to yourself by acknowledging you have a problem you’re trying to fix, it becomes sport to the media to pick on you,” he said. “It becomes hard to say, ‘We don’t care about the short-term publicity hit, what we care about is making the best movie.’ The political pressure against you becomes great and can make it seem like it’s better to leave it alone. Here, that pressure was even bigger because it is Brad Pitt, and because of the size of the solution. But I’m telling you right here, it was definitely the right call. We now have the best version of this movie, and people will see that soon.”

Moore understands that advance bad buzz often foreshadows a stinker. On John Carter, Disney gave way too much creative rope to first-time live-action helmer Andrew Stanton because he’d directed massive Pixar hits like Finding Nemo. And Battleship proved that no one should ever expect a branded board game to draw moviegoers, especially when the movie has nothing to do with the board game. Nobody was surprised when those films led to write-downs for their respective backers. World War Z had different problems. While Forster isn’t known for action, he’s a good director, and his subject matter of zombies is hot thanks to AMC’s can’t miss TV series The Walking Dead. All WWZ was missing was a plausible entire third act. The original ending was meant to launch a trilogy, but it took Pitt’s character down an obvious hero path — battling zombies mano-a-corpse in Russia — and it was implausible and unsatisfying. Moore, Brad Grey, Adam Goodman, Marc Evans, Brad Pitt and Dede Garner had a hard choice: spend a fortune on a fix that would leave audiences happy when they exited, even if that solution made the sequel more difficult to draw up. “If the first movie doesn’t work, then you’re never having a sequel,” Moore said. “But if you deliver a satisfying ending that makes that first movie a big hit globally, you can always figure out the next journey for Brad’s character. The most important question when you ask if there is going to be a sequel is, do people like the first movie? If you go in saying this is going to be three movies, and the first leaves you feeling incredibly unsatisfied, why would anybody want to come back and do it again?”

That was the reckoning moment they faced after Damon Lindelof watched WWZ‘s first two acts — but not the action-heavy original ending — and came up with a solve that is tense and really works. “We made an investment decision based on this great idea that would definitely improve the movie to the point that spending $15 million to $20 million would be worth it,” Moore said. “The movie would play substantially better, enough to be a hit globally and to potentially give rise to sequels. We now have that movie; we’ve screened it and watched the previews test right in line with the last Mission: Impossible.”

You can make the Citizen Kane of zombie movies, but at a certain price point, you cannibalize your chance to make money. Rumors about the WWZ budget have been all over the map. Studio insiders say the budget is $185 million; the numbers circulating around town put it at $210 or more. Moore was quick to dispel those high estimates, even if he wouldn’t address the budget number directly. He did say that even with a $125 million marketing spend for a global launch, there is plenty of room for upside if the film performs as Paramount thinks it can. He wasn’t confident of that before the re-shoots.

“On an investment of $300 million, if you look at global franchises, we like where we are,” Moore said. “G.I. Joe (which also had its release date moved to solve plot problems and facilitate a 3D conversion) will gross just under $400 million worldwide. This has one of the biggest stars on the planet in Brad Pitt, and we feel this has the potential to gross substantially more. Hansel and Gretel tripled its U.S. gross overseas, and G.I. Joe and Jack Reacher doubled it. There’s reason to believe WWZ will do at least that or better, so if you do $150 million domestic, you are looking at $450 million worldwide and if you do $200 million, you’re looking at $600 million. I base these numbers on tracking and Brad, and this ballpark seems reasonable to me if the movie’s good. Audiences are telling us that it is.”

Moore labels the higher budget rumors as ridiculous. Beyond the fact that Paramount shares its risk here with Skydance Productions, Hemisphere and GK Films, Moore said that the 3D on both G.I. Joe and WWZ added nothing to those upfront budgets because those companies supplied conversion services in exchange for an equity stake that will pay them only after each film reaches certain gross thresholds. “If your movie budget starts at $150 million, and you have overruns, and then reshoots, it isn’t complicated to figure out what happens,” he said. “You added another $10 million to $15 million on each one of those, and you’re at $175 million or $180 million. The math presented by people who claim to know the number is bizarre. You ask, how much does it cost for each shooting day? If it’s $400,000, then even if you shoot 50 days over schedule, that’s $20 million. Where else would the money go?”