In late August 1993, a young programmer named Dave Taylor walked into an office block on the Lyndon B Johnson freeway in Mesquite, Texas, to start a new job. The building had a jet black glass exterior and sat utterly incongruent amid acres of car parks, single-storey industrial units and strip malls. Game designer Sandy Petersen called it the Devil’s Rubik’s Cube. Taylor’s new workplace was on the sixth floor in office 615. The carpets, he discovered, were stained with spilled soda, the ceiling tiles yellowed by water leaks from above. But it was here that a team of five coders, artists and designers were working on arguably the most influential action video game ever made. This was id Software. This was Doom. By the time Taylor joined the company that day, fresh from his electrical engineering degree, id had already hammered out a dozen small-scale games for the digital magazine publisher Softdisk and the shareware pioneer Apogee. Its most recent title, Wolfenstein 3D, was an edgy Nazi shooter with fast-paced action and rudimentary polygonal environments. But when Taylor met id’s charismatic designer and coder John Romero, he was shown their next project, whose name was partly inspired by a line from the movie Color of Money. (“Doom” is what pool hustler Tom Cruise called his cue.) The concept was simple: Aliens meets The Evil Dead. But into this new project, Romero, the brilliant coder John Carmack and the artist Adrian Carmack had thrown all their obsessions: heavy metal, Dungeons & Dragons, gore, cutting-edge programming. “There were no critters in it yet,” recalls Taylor of that first demo. “There was no gaming stuff at all. It was really just a 3D engine. But you could move around it really fluidly and you got such a sense of immersion it was shocking. The renderer was kick ass and the textures were so gritty and cool. I thought I was looking at an in-game cinematic. And Romero is just the consummate demo man: he really feeds off of your energy. So as my jaw hit the floor, he got more and more animated. Doom was amazing, but John was at least half of that demo’s impact on me.” Romero brought a range of sensibilities to his game design ethos. As a kid, his home was full of board games and he adored building things, using the classic construction toys Lincoln Logs and Tinker Toys to create his own little worlds. When video games arrived in the late 1970s, he was fortunate enough to live beside a test arcade where new coin-ops were regularly swapped in to gauge popularity. Romero loved Pac-Man but he was also getting to play rarer titles – Mousetrap, Venture, Make Trax – and learning about the breadth of possible worlds and interactions. In late 1992, it had become clear that the 3D engine John Carmack was planning for Doom would speed up real-time rendering while also allowing the use of texture maps to add detail to environments. As a result, Romero’s ambition was to set Doom in architecturally complex worlds with multiple storeys, curved walls, moving platforms. A hellish Escher-esque mall of death. “Everything we’d seen before Doom was 90-degree hallways,” Romero says. “Bard’s Tale, Dungeon Master – all these games did the same kind of thing. I still classify Wolfenstein 3D as a maze game, just like everything that came before it. Doom was the first to combine huge rooms, stairways, dark areas and bright areas, and lava and all that stuff, creating a really elaborate abstract world. That was never possible before.” Romero had visited Disneyland as a child, and the exploratory nature of the experience, how each attraction allowed a glimpse at the next, had an impact on him. You can see it in the way the game uses dense verticality to add visual and navigational interest; the way windows, ledges and secret corridors were used to give tantalising glimpses of rooms or powerful weapons just out of reach. “I wanted the player to get these little peeks … to see that there’s something to get but they have to figure out how to get it, even if they feel like they’re breaking the rules,” says Romero. “The way that Disney wants to delight their customers, I want to delight the player. I want them to have fun when they find things which they feel only they’ve discovered. Pacing is what’s really important. There’s fighting and then there’s exploration, and you usually aren’t doing them at the same time. When you’re killing stuff, the focus is on that. And then when that’s done, you can look around and go, ‘OK, where am I? How do I get to the next thing?’ A lot of my level design is about letting the player have those spaces to think, absorb the environment and try and figure things out, because that’s really fun.” Romero wasn’t the only designer on Doom. Sandy Petersen joined id in the Summer of 1993. He had worked on Civilization at Microprose, and before that was at tabletop gaming company Chaoisum, where he’d designed for RuneQuest and created the influential horror classic Call of Cthulhu. He brought a different but complimentary sensibility, geared around the structure of role-playing adventures. He had just three months to create 20 maps, so he started building, using Romero’s DoomEd map editor. “I didn’t know what I was supposed to do, but I’d made plenty of D&D campaigns so I knew how a dungeon worked,” he says. “I built levels with hidden doors and monsters that would fight you, and lots of traps. I would sometimes get old dungeons I’d done for D&D and use them as the basis for making a map in Doom.” Using D&D as inspiration for a video game wasn’t new – it was well-established in computer role-playing games such as Ultima and Wizardry. But the way Doom combined fast-paced 3D action with elaborate, highly staged level design would prove hugely influential in the years to come. It’s there in every first-person action game we play today. Petersen loved to make maps that operated somewhere between theatre sets and escape rooms, enticing the player into micro narratives of risk and reward. “My signature thing was getting the player to walk knowingly into a trap,” laughs Petersen. “You enter a room and there’s a pillar with the [in-game weapon] BFG on it or something, and there’s a spotlight on that. And you know if you go pick it up, all hell’s going to break loose, but you can’t resist. John Romero was more likely to just teleport a monster behind you, and you had to know in advance where that was coming in. But there was always a clue in mine that you were about to get hit.” But Doom wasn’t just a single-player game. Carmack consumed an entire library of books on computer networking before working on the code that would allow players to connect their PCs via modem to a local area network (LAN) and play in the game together. Before Doom, two-player modem games were usually strategy or simulation titles with slow 2D visuals, such as Tele Chess or the Electronic Arts battle tactics game, Modem Wars, Genuinely multiplayer titles tended to be the preserve of mainframe computers running at university programming labs, where adventure games such as MUD prospered. But Doom brought fast-paced, real-time action, both competitive and cooperative, into the gaming mainstream. Seeing your friends battling imps and zombie space marines beside you in a virtual world was an exhilarating experience. “It was a high speed multiplayer death fest,” says Romero, who coined the term Deathmatch for the vs mode. “I was just like, obviously this will be all-consuming. This is going to be the best game that has ever existed on the planet.” But he also saw how it could influence the whole games industry, not just shooters. “I thought, this could really be the killer mode for any game, and it’s only going to get better because at that time, networking cards and cables were just barely being sold ... This was the future.” He was right. When Doom was launched on 10 December 1993, it became immediately clear that the game was all-consuming – id Software had chosen to make the abbreviated shareware version available via the FTP site of the University of Wisconsin-Madison, but that crashed almost immediately, bringing the institution’s network to its knees. Large Doom communities sprang up on bulletin boards and forums, and within a couple of months a homebrew level editor had been hacked together by fans. It wasn’t just the fast-paced action that drew people in, it was the entire structure of the game. “We changed the rules of design,” says Romero. “Getting rid of lives, which was an arcade holdover that every game had; getting rid of score because it was not the goal of the game. We wanted to make it so that, if the player died, they’d just start that level over – we were constantly pushing them forward. The game’s attitude was, I want you to keep playing. We wanted to get people to the point where they always needed more.” Everything in the game serves that sense of momentum. Early on in development, there were collectible items such as treasure chests – the standard loot of the role-player adventure. But they were jettisoned, because score was irrelevant. Collection was irrelevant. Instead, pick-ups were there to aid the player’s progress: new guns, more ammo, more power. As Romero explains, “We were just putting the cool stuff in there like invincibility and radiation suits and the invisibility artefacts and full maps … all of those things contribute to what you’re trying to do in the game. Design-wise, we defined our core loop – which is running and shooting, and anything that supported that.” Cheats and secrets were also a part of this recipe. It was programmer Dave Taylor who ensured that there were plenty of ways – usually involving typable codes – to skip sections and earn power-ups. “We needed it for debugging,” he says. “When you’re running through a level over and over again trying to find some bug, you don’t want to actually play the game, you want to get to the bug – especially in my case, because the game made me so nauseous, I was well motivated to get those cheat codes in.” But it was also Taylor’s idea to leave them in for players to find, ensuring that key-press combinations such as IDKFA and IDDQD became legendary. There’s a tendency to characterise id Software at this time as a kind of chaotic geek’s frathouse – all pounding heavy metal, pizza deliveries and caffeine-charged soda. But what drove the company was efficiency and craftsmanship. “It was sort of a productiv-ocracy,” says Taylor. “If you could deliver, then you could do whatever. So yeah, when I added those cheat codes, I didn’t have to ask for permission or anything, I just put ’em in. That freed us up to really focus on polishing, how it felt, how satisfying it was, the little subtleties. The artist drew buttholes on every bad guy, even though most people didn’t realise because you generally only see them from the front. But other little things – like when a monster shoots another monster, it makes him mad and he shoots back – that adds a lot of character, I think.” There will be many essays written this month, talking about the multifaceted legacy of Doom. And it’s true that this thing effectively invented the modern PC games industry, as a place dominated by technologically advanced action shooters. It created the online multiplayer deathmatch, and it allowed players to access the scripting tools to create their own maps, boosting the modding community. Romero’s decision to license the Doom engine to other developers – famously to Raven for Heretic and Hexen – created a whole new business model of marketable development middleware. The fact that the game allowed players to record their routes through the levels kickstarted the speed-running scene. This is all vitally important stuff. But that’s not really why we remember Doom 30 years later. There’s a joke now, which is asked of any new technology: does it run Doom? And invariably, if it has a screen and a CPU, it does. Doom runs on every console and computer, it runs on a cash machine, an electronic pregnancy tester and on internet-connected fridge freezers. Doom now even runs inside Doom. Why? Because Doom remains a brilliant, thrilling game experience. It is so pure, so focused. Not a single pixel is wasted. “Today, playing Doom at full speed, it’s [still] one of the fastest games you can play,” says Romero, who is currently working on Sigil 2, a spiritual successor to the original Doom series. “You still get an amazing experience, even better than when we released it, because it’s a little smoother. Doom is still very fast, very challenging. It doesn’t matter what the resolution is … it’s all gameplay.”