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A remarkable mural lines both sides of a hallway on the first floor of Treyarch’s offices. Created by iam8bit and artist Dave Crosland, it tells the story of the developer’s branch of the Call of Duty franchise.

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Meet the studio behind Call of Duty: Black Ops and Zombies mode

Before the reveal of Black Ops 4, Treyarch looks back at its work on Call of Duty

Charlie Hall/Polygon
Charlie Hall is Polygon’s tabletop editor. In 10-plus years as a journalist & photographer, he has covered simulation, strategy, and spacefaring games, as well as public policy.

In March, Polygon received an invitation to visit Treyarch, one of Activision’s most prolific studios. The invitation was fairly straightforward: Come to Santa Monica, California, for a full day. Talk with one of the teams working on Call of Duty, one of the world’s biggest video game franchises, and tell their story.

But Treyarch’s story is more than just the story of Black Ops, the popular subfranchise that the studio created. It’s also the story of the Zombies game mode, a whole other subfranchise that Treyarch helped introduce to the world — one that’s now a staple of every modern Call of Duty release.

At the same time, it’s the story of how a group of specialized game developers put its own spin on Call of Duty’s multiplayer, a popular mode and a competitive esport in its own right.

It turns out that Treyarch’s story isn’t one single story at all. In actuality, it’s three stories rolled into one.


My day began with a walking tour of the studio. My guide was Treyarch chairman Mark Lamia. Aside from a southern Californian’s year-round tan, Lamia could easily be the sitcom stand-in for your average midwestern American dad. The only difference is that this dad has been making video games for more than 22 years.

cover of original Call of Duty for Windows
The original Call of Duty was published for Windows PC in 2003.
Infinity Ward/Activision

Lamia comes from the publishing world, where he worked, for a time, at Activision’s home base.

“We had started working with Infinity Ward on Call of Duty,” Lamia said. “We knew we were going to make an expansion pack and begin the franchise.” To make it happen, Activision tapped its newest acquisition, a small team called Gray Matter Interactive Studios.

Activision acquired Gray Matter in 2002, hot off the success of its critically acclaimed Return to Castle Wolfenstein, a first-person shooter that blended exceptional gunplay with the occult. Lamia said that Activision saw remarkable promise in the young studio and its team of around 20 talented developers. It put a lot of trust in them when it tasked them with creating the first expansion pack for Call of Duty, called United Offensive, in 2004.

But the resources required to make the next generation of first-person shooters were beyond them. They needed reinforcements, and they needed them badly.

“We saw that the asset requirements and just the demands of making these games required a lot. A lot of work and a lot of people,” Lamia said. “They were just too small of an organization. Meanwhile, Treyarch had some great console capabilities.”

Treyarch chairman Mark Lamia in the lobby of the studio’s offices near Los Angeles in 2018.
Treyarch chairman Mark Lamia in the lobby of the studio’s offices near Los Angeles.
Charlie Hall/Polygon

In the late 1990s and early 2000s, Treyarch, another California game studio, punched well above its weight. It was banging out AAA titles at a blistering pace, releasing six full games across multiple genres on four platforms between 2002 and 2004. That’s part of the reason why Activision acquired it in 2001.

Cover art for the manual packed inside every copy of Call of Duty 2: Big Red One. Treyarch/Activision

But the studio didn’t rest on its laurels. In 2005, the pace of its releases slowed down just a touch, but the risk ratcheted up. That’s the year Treyarch shipped both Ultimate Spider-Man and its own stand-alone Call of Duty title, a celebration of the U.S. Army’s First Infantry Division subtitled Big Red One.

It was around that time that Activision made the decision to fold Gray Matter and Treyarch together. In 2006, the newly integrated team turned on its heel and shipped Call of Duty 3. The following year, it launched Spider-Man 3. When Lamia arrived in 2008, the studio was nearing the release of three more AAA games at the same time. The work was grueling.

“We shipped Call of Duty: World at War and 007: Quantum of Solace both shooters,” Lamia said, sounding tired for a moment. “Then, also, Spider-Man: Web of Shadows with our partner studio at Shaba Games. It became evidently clear that this team was onto something special inside the Call of Duty franchise, and if I could just focus them and could get all those teams together and working together, I thought we could do something great.”

The challenge, Lamia said, was convincing the folks back at Activision to give Treyarch the time and the resources to make it happen.

Time enough at last

“Working at that pace was one of the most challenging things ever. It was brutal,” Lamia said. “I was able to talk to Activision. I said, ‘Instead of us having to make three games at the same time, can we put all of our attention, all of our focus, can we have all of our leadership directed on making one great game?”

Lamia said it was in part his efforts on behalf of the team at Treyarch that got the studio the luxury of taking two full years to create Call of Duty: Black Ops, one of the most successful titles in the franchise’s history.

“I just wanted these teams to be able to do their best at whatever they were doing,” he said. “I felt like spreading our focus across multiple games didn’t allow us to do that. So Black Ops was really the first time we were able to entirely focus all of our efforts.”

Call of Duty: Black Ops - soldier firing as tank gunner fires in the background
Call of Duty: Black Ops tells a fictional story centered around the CIA’s clandestine operations in locations such as Laos, Kazakhstan and Cuba.
Image: Treyarch/Activision

We stood in a narrow hallway as he said it, surrounded by art from those first few Call of Duty titles that the unified Gray Matter and Treyarch teams had made, together. Lamia cracked a half smile while pointing at the framed, poster-sized copy of Black Ops’ original cover.

“Of course, then we went ahead and made three games in one instead of three separate games.”

In the end, Activision’s gamble was a success. Combining Gray Matter with Treyarch paid off. The new studio flourished.

Call of Duty: Black Ops was released in 2010. By Activision’s account, it set an “entertainment launch opening record.” The first title in the series sold so well that the publisher compared Call of Duty’s achievements not against those of other video games, but against those of the movie industry. It was followed by Black Ops 2 in 2012 and later by Black Ops 3, which were likewise wildly successful.

Treyarch’s series gave the Call of Duty franchise something it had never had before: a contiguous storyline. The Black Ops games carry players through fictional portrayals of the United States’ lesser-known, covert misadventures in Asia, the Caribbean and Central America. Black Ops 3 in particular extended that narrative out into the speculative future of warfare.

The Black Ops series stood apart from Activision’s other blockbuster titles produced by its stable of high-achieving studios — games like Modern Warfare, Advanced Warfare and Infinite Warfare. Treyarch’s single-player campaigns remained cohesive and distinct, telling a parallel tale of espionage and heroism.

Before, where Treyarch was merely one of several studios doing its part toiling away in the Call of Duty universe, today it feels as though Treyarch could have the momentum to truly push the Call of Duty franchise forward.

Call of Duty: Black Ops 2 - soldiers flying wingsuits
Call of Duty: Black Ops 2 moved the series into the speculative future of warfare, including one scene where troops dropped into combat flying powered wing suits.

The shambling dead

Oddly enough, it could be said that Treyarch’s biggest achievement hasn’t been the single-player story that it has feathered together over the years. Rather, it’s the studio’s bizarre foray back into the occult, something it hadn’t dabbled in since Gray Matter’s visit to Castle Wolfenstein. It’s a wild amalgam of history, fantasy, militaria and pop culture known as Call of Duty’s Zombies mode.

Dan Bunting, co-studio head of Treyarch, said that Zombies evolved almost organically from the work on 2008’s Call of Duty: World at War. At the time, his team had already spent months ripping its proprietary software apart to support a new and ambitious feature — a multiplayer cooperative mode. While the guts of the engine were exposed, a small team at Treyarch got a wild idea.

“We were on two-year development cycles,” Bunting began, with almost a sigh of relief. “The first year was like taking the car engine apart. All the pieces were laying on the floor, and then we had to put it back together [...] so you could actually play it.”

Art from the cover of the manual packaged inside each copy of Call of Duty: World At War Treyarch/Activision

“There was this learning process,” Bunting continued. “It wasn’t until the early part of the second year, where it’s like, ‘Man, [...] the most fun you can have is just defending an objective with each other!’ Those defend events were the most fun that you could have in cooperative play.

“I can remember right now, very vividly, this very rough test map,” Bunting said. “An engineer built it, so it wasn’t even a designer. [...] It was a very ‘skunkworks’ type of project. Only a couple people were working on it.”

So the team set about uncovering a scenario where two players could stand practically back to back, whaling away on the enemy AI. The result, Bunting said, was a “rough and dirty” test map inside a bunker where wave after wave of enemies would spawn in, with each one becoming more powerful than the last.

But the new cooperative mode was missing a theme, something to differentiate it and give it character.

Late in the development of World at War, Treyarch had invited a bunch of actors into its motion capture studio to record a scene set on the Pacific island of Peleliu. In 1944, the U.S. Marine Corps and the U.S. Army worked together to liberate the tiny coral island from the Japanese Imperial Army. The death toll on both sides was absurd. In Treyarch’s interpretation of that battle’s climax, U.S. air assets mercilessly bombarded Japanese soldiers. Players bore witness to the aftermath, with dozens of enemy soldiers emerging from their fortifications dazed, shambling drunkenly from the concussive shock of the bombs.

“Watching them, we thought, ‘These look like zombies,’” Bunting said. And so, for that motion capture session’s final few takes, that was the direction given to the actors: Pretend that you are zombies.

The result was magic.

“This was late, late, late in development,” Bunting said. “That same engineer came in one weekend and he just prototyped.”

In that hastily made second draft of the bunker, players were given the opportunity to purchase weapons hung on the wall with points they had earned. They were encouraged to board up the bunker’s windows to create choke points. Then the waves of enemies turned into zombies, using the motion-captured performances and new undead skins fashioned by Treyarch artists. In that way, Treyarch created its signature Zombies mode from shell-shocked Japanese troops.

Some fans criticized it for how far the subject matter strayed from what the series had established, but a large portion of the community fell in love with it.

Since that time, it’s those fans who have helped Call of Duty’s zombies become what they are. Treyarch’s ambitious new game mode was so successful that it crossed over, becoming a major part of every modern Call of Duty release, even those produced by other Activision studios.

The hook, oddly enough, was in the audio.

“Originally, it was a gameplay mode that was fun and we all really enjoyed it,” said Craig Houston, who has been the lead writer on Treyarch’s Zombies mode since the beginning. “We were very deep in the campaign of World at War, which was pretty heavy and pretty harrowing. Zombies was a bit of a fun distraction, both as a gameplay type and also, it just felt like something fresh.

The Call of Duty franchise is known for its pioneering work in performance capture. This sequence was created inside Treyarch’s own state-of-the-art motion capture facility in California.

“When it really started going was in the audio department, who, right from that very first map, were building in creepy, atmospheric things that people started to pick up on and go, ‘Why is that weird radio sound there? Who could possibly be on the other end of that radio? What does that mean?’ And that is really where your guys ran with things in the very early days.”

Since 2008, Treyarch’s Zombies mode has become more than just an amalgam of classic Call of Duty gunplay, intense cooperative multiplayer action and interdimensional weirdness. The time-hopping storyline spans the Prohibition era and both world wars into the modern day and beyond. One particular level features a fantastical version of war-torn Stalingrad with giant robots and fire-breathing dragons. Characters range from B-movie tropes to Fidel Castro, Richard Nixon and horror director George A. Romero.

To even attempt to explain the plot line of Treyarch’s Zombies would require another feature-length story entirely. Rather than a linear synopsis, the studio gave fans a poster that presents an incomplete timeline that loops back on itself, breaking the barrier between multiple realities in the process. Instead of putting fans into hysterics, it actually encouraged to them to return to old games and reinterpret the story.

“The fundamental thing about Zombies is, it’s a different experience every time you play it,” Houston said. “It’s largely nonlinear, which goes for the dialogue as well, meaning when you write a bunch of lines for characters, they’re based on triggers. If you’ve got a headshot from over 20 feet away, your character will say one of his headshot lines.

“You build and build and build this stuff into the game, and it means that it can always come up in a different order, which is narratively quite challenging. So we built that in as well. There’s this ‘element 115’ that exists in the universe, and it fucks with people’s memories. So they get confused, which allows you to have characters be characters, but not forcing them to have a kind of chronological experience through the map. Once they’re into it for five minutes, the characters themselves have almost forgotten why they’re there. They’re just going with their base instinct.”

Call of Duty Zombies full timeline
The full timeline for Treyarch’s Zombies is a gift to fans. It was first published in the lead-up to Zombies Chronicles, a set of original Zombies levels remastered for Call of Duty: Black Ops 3. The final art was revealed in a video hosted from inside the college apartment of one of the franchise’s biggest fans.

It’s good to play together

Call of Duty 4: Modern Warfare revolutionized first-person shooters when it was released in 2007. That game leaned into the traditional class-based model of a multiplayer FPS, giving fans the option to load out as a lightly armed, fast moving scout or a heavily armored support soldier with a light machine gun. The more you played, the more goodies you unlocked in the form of perks and weapon attachments. They were incremental, to be sure, but that ability to specialize along with the expertly designed maps made the game an instant classic.

To date, Call of Duty 4 is the only title in the franchise that Activision has seen fit to remaster, in painstaking detail.

So when the team at Treyarch stepped up with Black Ops 2, it knew the bar was already set high. It still wanted to put its own spin on things. The goal was to allow players even more flexibility when customizing their loadouts. The solution was the “Pick 10” system. It quickly became a fan favorite.

Rather than simply offering a few options for each character slot, Treyarch instead assigned a numerical value to each weapon, attachments and perk. Before dropping into a match, players could pick up to 10 points’ worth of items for their character. It allowed for a new level of customization.

Call of Duty: Black Ops 2 - combat near the crashed plane on the Turbine multiplayer map
Turbine, a multiplayer map from Call of Duty: Black Ops 2.

It also added a lot more variables, which opened up a giant can of worms for the designers at Treyarch. How do you even begin to balance a multiplayer title when players are incentivized to create builds that unbalance the game?

To answer difficult questions like that, the team at Treyarch turns to its own internal playbook, a combination of best practices and hard-won experience. There’s no better embodiment of that lore than design director David Vonderhaar, who has been with the team since the 2005 release of Big Red One.

I pressed Vonderhaar and Bunting to give an example of how Treyarch solves design problems differently from its peers. The room became uncomfortably quiet for a moment. It felt like everyone present was exchanging a bunch of nonverbal cues, trying to make sure they weren’t the first one to blurt out a closely held trade secret. That’s when Vonderhaar chimed in.

“Back when we were making World at War,” he said, “we were getting a lot of feedback from players that was, essentially, ‘These maps aren’t fun.’ That was the note.”

One level in particular that was no fun at all, he said, featured an eight-way intersection. Designers and artists loved it, but players hated it. It took the team a long time to break down the reasons why it wasn’t working.

As it turns out, Vonderhaar explained, there are no eight-way intersections in FPS maps that are fun. Because they can’t be. On consoles, players have a fairly limited field of view. If they’re lucky, they can see in three of those eight directions at once. Any more than that, and you can’t turn fast enough to protect yourself. Alternately, players might pause for a moment as they decide which direction to exit — and then get shot in the back.

“We realized that eight-way intersections are not fun because you’re not having head-to-head engagements,” Vonderhaar said. “All the levels that were fun, you could walk into a space and pull up your weapon, and you knew where the enemy could be. They’re not typically behind you, because whatever you came through, you would have ran into that person. But when you run into an eight-way intersection, you can get shot from eight ways. So of course it’s not fun.”

Havoc is a downloadable map available for Call of Duty: Black Ops 3.
Havoc is a downloadable map available for Call of Duty: Black Ops 3.

The solution was to rebuild that portion of the level, and keep that guidance on hand for every future level in every future game that Treyarch ever made.

But how do you transform that rule into direction for a team of designers and artists? Vonderhaar helped to coin a phrase, called the “lane check,” to suss out when players were being presented with intersections that were too large. Internalizing the lane check, and internalizing the thousand other tiny concepts that Treyarch has learned over the years, gives the team a tremendous competitive advantage.

It’s that institutional knowledge that has enabled Treyarch to tackle radical design challenges, like the cybernetic physical augmentations that were so integral to the plot line and gameplay of Call of Duty: Black Ops 3. As it turns out, there are many more potential eight-way intersections when players can leap off the ground and go anywhere they want in three dimensions.

“I probably have rose-tinted glasses about history on these things,” Vonderhaar said, “but I remember working on wall-running in Black Ops 3. At the time, the lead level designer for multiplayer and I said to the team, ‘Just apply the rules. Apply our playbook. Apply the same exact set of principles that we have in the past.’

“Whether you’re walking into a room with eight doors or running up the side of a wall onto a catwalk, the principles are the same. You have to collide people together. You can’t put people in unpredictable spaces.”

After learning so much about the history of the studio that morning, I hadn’t expected my day to end with a kind of philosophy lecture. But Vonderhaar was adamant about his team’s process.

“We have to ask, ‘What experience are we trying to create?’” Vonderhaar continued. “‘How do we measure if we’ve created it, and what are the things that are necessary to do that again?’ And when all of those come together, that’s when we make our best designs. Because it takes everybody here being on the same page to make the best game.”

Black Ops 4

For more than three thousand words so far, there’s been an elephant in the room. If you’ve been paying attention to the news, you know that its name is Call of Duty: Black Ops 4. Word began circulating in February that Treyarch was working on it, and Activision formally announced it in March for a scheduled release date of Oct. 12 on PlayStation 4, Windows PC and Xbox One.

Virtually everything else about that game is still privileged information, none of which was shared with me during my visit. I was sequestered on the first floor of Treyarch’s office building the entire time, and it was clear that even those few offices and common areas had been sanitized before I was allowed to come in. One massive landscape-style poster was even covered over with a garbage bag.

We knew what to expect when Polygon was invited out. We were expressly told that Treyarch wouldn’t be able to talk about Black Ops 4. That reveal had been reserved for just over a week from now, on May 17.

The Call of Duty franchise has had a few hiccups in the last couple of years, and those hiccups have likely impacted the series’ bottom line. When Infinity Ward’s Infinite Warfare was announced in May 2016, the trailer quickly became the most disliked YouTube video of all time. Despite critical praise, including from our reviews team here at Polygon, when the financial reports came out, it was clear that sales had flagged.

Activision then announced that the next title would “take Call of Duty back to its roots.” The resulting product, Sledgehammer Games’ Call of Duty: WWII, was initially set back by technical problems in its multiplayer mode. Despite its rocky start, it still managed to sell twice as many copies as Infinite Warfare.

After I returned from Santa Monica, Polygon reported that Black Ops 4 won’t include a standard single-player story mode, which would make it the first mainline Call of Duty game to ship without a traditional campaign. Perhaps the mode will be replaced by something else, like the battle royale mode reported on by CharlieIntel, Kotaku and Eurogamer. Perhaps the decision to cut the story mode is an opportunity for the team to make an attempt at streamlining its process again, finally whittling down its workload from three games in one to a more manageable two. Or maybe there’s another reason entirely. Neither Activision nor Treyarch provided comment specifically on the claims in the report. An Activision spokesperson said, “We don’t comment on rumor and speculation. We look forward to revealing Black Ops 4 on May 17th.”

Whatever is revealed next week, it seems Treyarch’s studio co-head Dan Bunting is confident in his process and the tenured team that he has at his side.

“The scrappy underdog mentality really defines a big part of what our culture is here,” Bunting said. “I don’t know really where it came from, but it was probably just part of the history of the studio from the early, early days. It was just trying to work from job to job and get, as an independent studio, work wherever it could find it.

“Then, as the Call of Duty franchise expanded and came into the studio, it was also a team that was always trying to prove itself in this new era, in this new genre, and so I think that was built into who we became as a people. There’s a lot of humility built into this studio.”