Nazi Zombies, Ray Guns and Magic Chests

November 11, 2008 10:03 pm Sir Haxington Game Development, Gaming

Early in the development of Call of Duty: World at War, myself and the Lead Level Designer at the time, Jason McCord, were trying to come up with cool “extras” for the game. For example, CoD 4 had the airplane level at the very end of the game which arguably IW could have shipped without. At the time, we didn’t have anything planned besides “competitive co-op,” which is a lot like arcade mode in CoD4, just co-opified.

We had kicked and idea for an end sequence in CoD:WaW where you’d be placed in a bunker which you couldn’t leave. To your right would be a German officer screaming at you to get on some MGs, and to your left would be those MGs mounted on a window over looking a beach. It was then the player was supposed to realize that you were on the beaches of Normandy from the German perspective, and you had to mow down allies as they came up the beach. Eventually, towards the end of the credits, as the pace got to be too heavy and there were so many guys that eventually they broke through the beach head, you’d hear banging on the door to the bunker. A few seconds later, an explosion would rip through the bunker, knock you unconscious, and you’d be on the ground, facing up. An American squad would light up the place and a bad-ass US soldier would stop over you, slowly aim his gun at you and fire. Fade to black. Finish rolling the credits.

Hmm, actually, that still sounds pretty cool. Unfortunately, there was a lot of resistance against playing as a German, even though the players gets owned at the end and the Americans still win. What could have been a cool cinematic and interactive ending to the game never was.

Later in the project, we added some AI to the level “Little Resistance” (second level in the game) which had Japanese soldiers looking dazed after a rocket strike on their defensive line. These guys sort of stumbled around and every time someone saw those animations, they mentioned how they looked like zombies.

So months passed. One of our producers, Dan Bunting comes in and says “We want to do some extra content for the game, what should we do?” I still really liked the concept of being over run and not really being able to win. One thing that is common in most Call of Duty games is the feeling that you’re invincible, that when things go wrong you’ll be okay, and that everyone lives to see the next day. I think IW did a good job in twisting that safeness with two of their levels in particular. The level where you’re being led through the streets of a Middle Eastern city in the back of a beat up car and eventually shot in the face by one of the antagonists, and the level where you survive a nuclear explosion and eventually die anyway. Bonus points for making them crucial to the story.

Anyway, the first thing I asked Dan was if he’d ever played any “Tower Defense” games. He hadn’t, so I explained how the mechanics are pretty simple (guys come in, at the end of each round you use the points you’ve accumulated to buy various objects / abilities that will help you survive to the next round, repeat until dead) and we could do one fairly easily. Because tower defense games had been proved in Flash form time and time again doing our own version of tower defense could be a pretty big hit.

The model for the extra content I really wanted to follow was that of Geometry Wars. As you might know, Geometry Wars was a game that started as a mini-game in Project Gotham Racing 2. Eventually, the game became so popular that Bizarre split Geometry Wars out into a separate game, available on Xbox Live. This model for extra game content is ingenious for two major reasons: one, players get a really fun bit of extra content with a high replay value, and two, the development team can use this opportunity to explore and test new ideas and projects. If everything works out, the fans are happy and you have a prototype for another game.

A few hours after talking to Dan about doing the extra content, I was taking to one of our designers, Sean Slayback, about tower defense games and the proposal to make one. He mentioned a game called “The Last Stand“, which is a flash game where you play as a survivor fighting off zombies. Zombies run towards you and start tearing at a large barricade that is protecting your area. If they break through, you’re pretty much toast, so you move around in your little section of the screen shooting various guns to try to keep them from breaking in. The rules are pretty standard for a tower defense game but with some cool twists. After every round, you get some points which you can spend on building back your barricade, looking for survivors, and looking for new weapons. So depending on how you play, you might choose to get a new weapon, or more people to help you defend, or simply build up your defenses.

So, I played a few rounds and had a huge epiphany. “Zombie Nazis!” I thought to myself. You could do a lot of the same stuff here, but make it more interactive and more intense in the first person. What you you could actually buy barricades in real time? What if you actually could find and buy weapons in the level? What if you could unlock new areas that changed the strategy of the game and the flow of the enemies? Plus you could play in co-op! We have zombie-like animations already (the dazed guys), this is a no-brainier prototype! The engine supported all these ideas and I could immediately see how they could be implemented.

I immediately rushed over to Dan’s office. “Hey, so I have this idea, I think it’s going to be awesome. Let’s do a tower defense game where zombies are attacking a building you’re holed up in!” You could tell that he wasn’t sold on the idea. I gave him my pitch anyway but he wasn’t terribly impressed, even after showing him “The Last Stand”. He told me we wouldn’t have enough time to make it, doing such a game mode would require all new assets, it’d be a huge risk, the mode didn’t fit the theme of the game at all plus it would be too campy. However, when I started pitching the idea to others on the team, they seemed to love it, especially some guys that had played a lot of WarCraft or StarCraft and knew a lot about tower defense games (those blizzard game were where the Tower Defense craze got really popular).

I sat on the idea for a while. Later, I learned that Dan had grabbed a scripter and a programmer to implement his concept of what a tower defense game should be. It was named “Bunker Defense” and basically included sections of levels from the single player campaign. As you ran through the levels, guys would spawn in waves, eventually you’d encounter a flame guy, maybe some dogs. The problem though was that it was missing all the fundamentals of what makes a good tower defense game. You need to be able to buy stuff, rebuild, change your strategies, but most of all you have to defend. In Bunker Defense you were running and progressing through the level. In tower defense games you’re defending a particular area and you need to strategize.

Every week that went by more work went into Bunker Defense and every week was another week I said “We should drop this and do Zombie Nazis instead.” I always got the same lines. “Too risky,” “Too much work,” and so on.

After a few months, I decided to go off and prototype “Zombie Nazis” (originally Nazi and Zombie were flipped) over a weekend. I took one of the scary looking buildings from the Russian campaign, put boards all over the outside and made some contrast-y lighting. At first, I just used the dazed guy animations for locomotion, and had them “melee” through the boards to get into the building. I had doors you had to “buy” to open which unlocked the flamethrower, a couch you could “buy” to get up stairs, weapons on the walls you could purchase to get you into further rounds. All the core elements were there. It was rough but it got the idea across.

I showed off the prototype to a few people. The initial reaction was far better than I had hoped for. Other people could immediately see the potential, even with basically temp animations and limited geometry and script work. The prototype was immediately fun and got a range of positive reactions from people, so I knew we had a hit. The Creative Director, Corky Lehmkuhl, gave me the go-ahead to continue work on it. Dan, who had people working on Bunker Defense wanted to have both his concept and mine in production at the same time. After about a week though, Bunker Defense ended up being cut since it just wasn’t working out and there was only one programmer, Austin Krauss, assigned to making it work anyway.

Unfortunately, Austin and I were asked to work on Nazi Zombies in our spare time and on weekends since we were already in full crunch for the main game. We ended up doing just that. There were some features that were far from being complete. For example, in the prototype I had planned on being able to buy back boards but never got around to it. So once they were torn down that was it. At one stage Austin made it so you could buy them all back in one shot, and later he had it so you buy them back individually. I knew the board buying mechanic was a key part of the game play though, so I’m glad he got that working early on.

Our Lead Animator, Jimmy Zielinski, finally got around to playing the prototype and his head gibbed with excitement. “If you need any animations for this, just let me know.” I whipped up a wish list of animations and send them his way. The animators had a mo-cap session coming up soon, so he told me he was just going to get a bunch of zombie animations on the side.

One of my favorite parts of the “Nazi Zombie” saga is that, purely by chance, the day that the mo-cap session happened, one of the actors we had for the day actually plays a zombie at Universal CityWalk. So, here we are, working on this total side project, and as luck would have it we have one of the best actors possible for zombie animations. As a result, our prototype just got a million times better.

So, the animations looked awesome, which took Nazi Zombies to a whole new level. One of the artists, Cameron Petty, wanted to get involved and wanted to make special characters for Nazi Zombies. So, he zombied up the SS Honor Guard characters, made glowy eyes for them, and so on. We had a gibbing system set up from the main game, so we got special gibs made just for the zombies. Plus, we randomly burned some zombies in script so you’d get this mix of regular zombie guys and ultra-dirty, rotting looking guys.

Eventually we hacked in head gibbing. We didn’t have this feature in the main game (exploding U.S. Marine heads is offensive to a lot of people), but I figured out a way we could do it all in script. One bug we ran into was that a Zombie would run around with their head off and attack you every now and then. We actually thought it was awesome, and it stayed in, although we modified it so that guys eventually drop after a few seconds.

By this time I had moved the level away from the small house prototype and into one of the bunkers from the Pacific campaign. However, our Lead Multiplayer Designer, Chris Dionne, fixed up a bunch of geometry issues with it and made it not suck so much. I went in and adjusted all the doors and windows so that it fit with the game play better.

A few more weeks had passed, and Austin and I were still trying to put everything together on Saturdays and Sundays, even through we were working 12+ hours days Monday through Friday in addition to working on stuff for the main game on the weekends as well. I hate crunching, but we were super motivated to work on this.

I had the idea for the “Magic Chest” (people just starting calling it that, I used to call it the Mario Kart box) when we were still in the prototype phase, but never quite got around to implementing it. It wasn’t until we moved the prototype into the new map I started creating new interactive objects like the rifle cabinet, the treasure box (which was influenced from Mario Kart and a trip to Las Vegas) and so on. I knew that to keep the game interesting, there needed to be some randomness as well as some strategy to the game play. People simply loved going to the box and seeing what weapon they’d get so I knew it was a keeper.

The chalk outlines (where you can purchase weapons) didn’t come until much later, although you could always buy weapons even in the early prototype. I always wanted chalk outlines since day one. I sort of imaged it like the Hitman series, where there are outlines of weapons on the wall of your hideout, and as you progress they start showing up. Once our Lead Artist, Brian Anderson, starting playing some Zombies, he whipped up the chalk outlines, re-did the lighting and generally made it look pretty. He also fixed up the box with question marks on it, which was a nice polish touch.

So, in our spare time, we had this really awesome prototype going. Actually, by this time it was beyond a prototype. It was fully functional and fun, with rounds, boards you can buy back, actual zombie animations, near complete geomerty and lighting, a prototyped introscreen and so on.

However, at this point the thing is still buggy as hell still unbalanced (the first round would last like for like 30 zombies, it was just too slow) and Austin and I haven’t had a day off for months. We were at the point where we couldn’t actually work on it anymore, since the main game was requiring so much attention. There were plenty of points at which I was sure Nazi Zombies was going to be cut due to lack of man power. At one point Austin was pulled of to fight fires elsewhere on the project, so I thought for sure it was over.

Luckily, the upper management had the good sense to put our Lead Scripter, Mike Denny, as fully dedicated on “Nazi Zombies”, which it was now called officially. This basically brought the mode back from the dead (ha-ha). He fixed up a lot of remaining issues, polished the hell out of the various features (for example the couch was still just something you’d just buy and it’d go away, so he got had to idea to make it go up to the ceiling with FX) and generally just made it shine. We went back and fourth a lot with our Jimmy and another animator, Phillip Lozano, and played the hell out of it every night while doing tons of balancing on the fly to made sure Nazi Zombies played right. Early on you could get to like level 35 and beyond with ease. We wanted 10 to be the tipping point, with 20 being the point at which if anyone makes a mistake the game ends.

With only like a week or two before submission, I was satisfied with the game play but there was something still missing. Power-ups! I was heavily advised against it, but I added the four power-ups in a day of mad scripting. At first I just grabbed whatever models I could find that were kooky enough to be a power-up model. The original point doubler was a tea kettle. The first Insta-Kill was a crow model. Max Ammo was a rat, and the bomb was… well, a bomb.

Some people hated the drops at first. They had been playing a lot of Nazi Zombies, and thought it took away from the “survival horror aspect” of the game. But, that’s not what we were going for. Really, the most fun part about Nazi Zombies is playing with friends and seeing how long you can hold out. While the atmosphere is somewhat freaky, the game isn’t meant to be a serious survival horror game. It’s meant to be more arcadey and fun.

So the power-up went in, and all around the office you’d hear “GET THE BIRD, OH TEA KETTLE DOUBLE POINTS!” It was an awesome feeling. In fact, by this point in the project the team was mainly bug fixing and content locked (haha!) so everywhere you went in the office you’d see people playing Nazi Zombies. You could hear them across the office, yelling at each other for revives, talking trash about what levels they got to and how far, what strategies they used to get as far as they did, and so on. Nazi Zombies was the buzz of the office. People especially loved the Ray Gun.

The Ray Gun is another awesome, semi-accident that fit perfectly with Nazi Zombies. One of our weapon artists, Max Porter, did the Ray Gun as a total fun, side project for himself. One day he walked by and was like “Hey, want to see something cool?” That was pretty unlike him, so he brings me over to his desk shows me the the Ray Gun model in first person (it looked pretty finished minus the animations).

You should understand that we basically only see guys in olive drab carrying mp40s, thompsons, and garands all day, so this shit looked amazing. I knew then that we had to get animations, sounds and particles to make the Ray Gun shine. So, I went and grabbed our Audio Director, Brian Tuey, who was also amazed, and said he’d do sound for it. Our Particle FX Lead, Barry Whitney, said he’d do custom particles. Jimmy said he’d do animations for the gun. So, when it was all done, we had something that was just perfect as the ultimate Nazi Zombie killer. Once again, the stars aligned.

Meanwhile, Denny was still working full time on Nazi Zombies and adding a ton of polish to the power-ups as well, such as making the guys gib heads on insta-kill, guys catch on fire and gib when the bomb goes off and so on. Our Brian eventually gave us the new, shiny gold models you see today, which look much cooler.

I must admit I miss the crow though.

I could tell this was going to be an even bigger hit when everyone in the office is playing it and starting competitions. You’d hear screams all over the office when someone would get a bomb on level 16, or a max ammo when people are running low on ray gun ammo. It was a great way to pass the time when waiting for huge bugs or a disc to be burned. Competitive email chains starting going out with screenshots of the current Nazi Zombie score leader’s screen. One of our programmers hooked up the leader boards as a result. Another programmer and I hooked up the zombie crawls when their legs get blown out. Denny still plugged away, fixing all kinds of usability issues. I can’t stress enough how much more awesome Nazi Zombies became when he starting working on it.

Right up until the end we were finding little exploits. For example, people starting dying (on purpose) with the Ray Gun as you were given 160 bullets in the clip (full ammo) every time you were downed. So, people would sit at the bottom of some stairs, die, blast zombies, get revived and repeat. The tactic was cheesy as hell, but I’m glad people started using it so we could fix the exploit before it went out the door.

So, that’s it. A simple design with a cool theme, lots of luck, passion, and hard work from various team members who went out of their way to try something different. Sure, we didn’t get everything we wanted in there, but I’m fairly sure there will be more Nazi Zombies in the upcoming months. I really couldn’t be happier with the way Nazi Zombies turned out, all things considered.