On the first day of 1993, id Software published a press release announcing Doom. A first-person shooter designed to capitalize on the popularity of the studio's previous game, Wolfenstein 3D, Doom promised "revolutionary programming and advanced design" for players who stepped into the boots of soldiers pitted against hell's demons. More than that, id's enthusiastic young team boasted of 256-color VGA graphics, an engine able to render three-dimensional graphics in real-time, a panoply of textures to diversify surfaces, and cooperative and competitive play for up to four players over local area networks.

"This is the first game to really exploit the power of LANs and modems to their full potential," the press release gushed. "In 1993, we fully expect to be the number one cause of decreased productivity in businesses around the world."

Id's team had the enthusiasm, the technical savvy, and the creative drive. All that stood in their way of total world domination was one minor detail. They had to write the game.

"The engine for Doom was running even in January [1993], the very first month we were working on it," said John Romero, co-founder of id Software and co-creator of Wolfenstein 3D, Doom, and Quake.

Romero (left) and fellow coder Shawn Green cut loose during development of Doom. The open door in the background offers a peek into Romero's office.

Doom's canonized engine lived up to its prospects. The tech was an evolutionary leap beyond Wolfenstein 3D's orthogonal halls, single-floor levels, and corridors more brightly lit than the fluorescent bulbs that illuminate office cube farms. Floors could be chopped up into multiple segments, stairs extended between platforms of differing heights, elevators shuttled players between floors, walls curved to create sinuous pathways, and lighting ranged from blinding to pitch-black and every setting in between.

All those advancements amounted to nothing without DoomEd, the level editor Romero and fellow id co-founder and coding prodigy John Carmack authored together. Working on NeXTSTEP, a graphical operating system light years ahead of command-line systems like DOS, Carmack programmed the data structures that demarcated a level's parameters—namely sectors and lines—while Romero implemented support for points of view, textures, ceilings, and floors.

With DoomEd complete, Romero cracked his knuckles and dug in.

"By the end of January the engine was running," Romero continued. "The editor probably took, I'd say four months to make, and it was not modified after that. I basically made it and then started working on levels."

First in, Last Out

The opening shot of Doom E1M1.

Every level has two titles. "Hangar" is the Christian name for Doom's inaugural level. Doom's most devoted fans tend to disregard those descriptors in favor of the game's easy-to-follow syntax: E#M#, shorthand for episode and map number. To them, "Hangar" is and always will be E1M1.

Several factors elevate E1M1 as one of Doom's most popular maps, if not the most popular. Rooms vary in height and width. Items form a breadcrumb trail, guiding new players along the path to the exit. Two of its three secrets are easy to find, while the third requires some thought.

E1M1 is the apotheosis of Doom's level design, and there's a good reason for that. "You should make your first level last because you've created your design language," Romero explained. "You've been using it and refining it. If you're going to get people excited about your game immediately, the first level is where you do it. You're going to be using the latest, up-to-date design skills and language to create that beginning part of the game and introduce players, in any way you can, to all the cool stuff that's to come."

By the time Romero got around to crafting E1M1, he spoke DoomEd as fluently as he spoke English. The level players explored on release was his first draft. Romero made only one change. From the starting point, move forward and follow the curvature of the hall to an industrial door. In Doom's depiction of the future, doors don't swing open; they slide up and emit high-pitched squeals. Throw it open and enter the computer room, wall-to-wall terminals occupied by Sergeants (zombies toting shotguns) and the aptly named Zombieman, undead soldiers packing pistols.

E1M1: A flight of stairs inserted to show off variable height.

Prior to version 1.9 of the game, patched in February 1995, the computer room did not exist. "That room was kind of a hallway that had a couple of pillars in the center that were a dark-green color," Romero said, "and the ground was just brown, and it led into the next area with the zig-zag [bridge]. That was the only room where I basically said, 'This looks like crap. I need to make it look better.'"

Romero nailed E1M1's first room much earlier, although it went through its fair share of iteration. Tom Hall, then id Software's principal designer, had players starting in a small room facing a table littered with playing cards. No table object existed; instead, Romero or another designer would paste a texture depicting playing cards onto a crate. Hall, who envisioned wanted Doom to tell a proper story beyond Wolfenstein 3D's "shoot everything that moves" objective, the table had been abandoned mid-game because an alarm had sent soldiers running for their weapons.

"We didn't do that," Romero explained, "because that would have forced the player to do something instead of letting the player learn how to play that kind of a game. It wouldn't have given the player time to explore the environment and look around; it would have thrown them into an action scene like a lot of movies do, except you sit there and watch a movie. This was the first time people had seen an engine like this and they just wanted to look around."

Romero's slant on E1M1's first room exudes a calm-before-the-storm ambience. Players find themselves in a wide room bordered by grimy walls and computer terminals. Ahead, four pillars surround a recessed floor covered in blue carpeting. A mangled corpse rests near the center of the recessed area, its bloody entrails contrasting sharply with the floor's blue texture. The player's eye locks on to the body, exactly as Romero planned.

"He's dead in front of you; that means there's something bad happening, versus it just being a clean area."

Every room and hallway of E1M1 follows that old writer's axiom: "show, don't tell." To the left of the starting room, a side chamber contains stairs that trail up to a podium where a green suit of armor sits. Fighting their way through the computer room, players enter a chamber flooded with slime. A bridge zigzags across, but the way forward is impeded by zombies on the ground and, high up on a ledge, a leathery-skinned Imp, who brings a friend if players selected a higher difficulty level.

E1M1: Imps hurl fire from a ledge.

Usually, that lone Imp spots players before they spot it. It greets them by hurling a fireball. Most new players step to the side and stare in wonder as the projectile sails through the air and explodes against the wall in a burst of cinders.

"It was kind of crazy, putting the Imp in there, but it was kind of cool because it was the first time you could see his fireball flying through the air toward you," Romero said. "People had not seen that, either. We loved it, too. We had been making all the levels in the game for months and we wanted to make sure the player could see that this is a thing that will happen a lot more later on."

E1M1 doesn't pull out all the stops, but it comes close. Rooms with ceilings of variable height, long staircases, an Imp sniping from atop a ledge, and three secrets—just enough material to whet the player's appetite without playing every card in DoomEd's hand. "That's basic ramping: how do you get the player, at the very beginning, to learn things and then see something cool and see something cool? But don't blow it all at once; a few levels into the game and they'll have seen it all," said Romero.

Players who survive the slimy chamber pass through another door and enter a dimly lit room. Enemies are barely visible, vague forms shambling toward them. Just ahead is a door marked with an exit sign—and inside, on higher difficulty levels, waits an Imp, perfectly positioned to slash at the player's face as soon as they rush in.

Designers of contemporary games would call the Imp's placement a jump scare. Romero thought of it that way. He was keen to play to Doom's blend of action of horror. "After fighting, you'd get to do some exploration," he said of the game's pacing. "Otherwise the levels would be a blur. You need time to learn them, look around to see what you can see, and hopefully see a monster, shoot him, and not be able to attack you back—stuff like that to [reward] the player for exploration."

Doom's staccato rhythm of fighting and exploring was calculated. Romero drove players from areas such as an open-air elevated courtyard in E1M3 into a murkier chamber where a blue card rests on a pedestal. Naturally, players make haste for the card. Touching it triggers a scene straight out of a horror movie: the lights go out, a door behind the player grates open, and a mob of Imps silhouetted by sickly yellow light come slithering out of a secret chamber.

E1M3: Grab the blue key and run.

Players who keep their wits about them should notice a well-placed lamp through the darkness, marking the passage where they came in.

"The first time you get it," Romero said of the blue key, "if you turn when you hear the [door] hissing, you see a dimly lit room behind the silhouettes coming toward you, which is really cool. That's why I put the bright lights in the corner: you know where the exit is and can get out of there."

E1M1 flows perfectly as a single-player level, but it shines in multiplayer, too. It's spacious enough to accommodate four players in deathmatch, yet intimate enough that two players won't have to wait long to find action in a one-on-one contest. Despite prominent mention in the press release, multiplayer was a famously late addition.

"We designed everything to be single-player until the last couple of months, when we actually put multiplayer in the game," Romero recalled. "Then we had to go through and add multiplayer starting points, weapons, and balance all the levels."

Balancing levels for cooperative and deathmatch play was as simple as firing up DoomEd and sprinkling in weapons and enemies—such as the rocket launcher found in E1M1's courtyard, near the pond of toxic ooze that holds blue power armor—set to appear only in multiplayer.

"We're talking a couple of days," Romero said of rigging the game's 27 single-player maps for deathmatch and co-op play. "It was pretty quick. We just knew that that was going to be a world killer."

Work in Progress

E1M1 represented peak Doom level design. E1M2, also known as "Nuclear Plant," was the opposite, at least at first.

"Doom E1M2 is the level that had the most work done on it, since I started it pretty early," Romero said. "In fact I decided to think about how we were going to make levels for this game. We had no idea. We were making Wolfenstein-type stuff for months because it was hard to get out of that mindset. That was all we had seen. We had these cool abilities in this engine, and we needed to really think about how we were going to use them."

Romero broke ground on E1M2 in April of '93. He started by building pieces. A wide set of stairs curves up and around 90 degrees, leading to a hallway that opens into a cavernous room. Romero played with his room's lighting until the room's contours were barely distinguishable—a counterpoint to Wolfenstein 3D's blinding spaces.

"I made the room dark. I made tall areas," Romero said. "There weren't any monsters in the map at this time, during development of the game. It was too early for monsters, but I pictured there would be monsters up there, so I made those areas brighter. I went in and got the scale right, all that stuff, and thought it looked really cool."

E1M2: Stairs curve upward, leading to Romero's first breakthrough in Doom level design.

Romero called in Tom Hall and a few other designers to show off his creation. They were floored. The room's walls were angled so that there were no corners, only angles near where corners would be.

"When you're making levels, you create this checklist, detailed rules for your game," said Romero. "The number-one rule was: if you could make this room in Wolfenstein, you have failed. Whenever we were making any room, it shouldn't exist in Wolfenstein. If it could, you need to alter it and make it cooler because nobody wants to see the last game in [your current] game. That was the rule even later on. When we were making Quake, the rule was that if you could make this room in Doom, you've failed."

Over time, Romero's shadowy space in E1M2 became one of Doom's most infamous areas. Expanding on it, Romero stretched out the preceding hallway, filled it with toxic waste, cranked up the lights, and planted blue vials of health along a bridge over the ooze that ended at a box of shotgun shells sat on the elevator.

Bright lights, safe passage over toxic waste, and a box of shells out in the open? Astute players grew nervous.

"This all leads up to something," Romero said. "You're in a room at the top of these stairs with just a little path over the slim. There's some health, and then some shotgun shells. So it's like, 'They always give me this stuff when bad things are going to happen.'"

The siren's call of the box of shells proves too tempting. Players race forward to grab it. Touching the elevator sends it plummeting down into the pitch-black room that Romero had created, only enemies swarm its depths, captained by Imp sentries raining down fireballs from alcoves set high up on walls.

"That was another instance of me thinking, I bet they won't expect this to happen," Romero described, "going down into and seeing a huge room, and getting attacked while you're coming down, versus just taking a big elevator down, and then it opens into a room. I thought it was more interesting to show the whole room as you're going down, and to be vulnerable that way."

E1M2: Surprise!

Happy with his proof of concept, Romero added other pieces. Just before the winding staircase that leads to his death trap, an opening to the right reveals another slime-covered space notable for a single pillar in the center. The side of the pillar that players see upon entering the room is plain, but behind it is a switch. Flipping it causes a faint squeal—a door, or perhaps a secret panel, yawning open.

It's the latter, evidenced by a huge gap in a previously solid wall across from the slime room. Step through the gap, and players pass out of dazzling corridors and into a warren of corridors, most of which are blanketed in darkness. All summed up, the secret area is roughly the same size as the passages players are meant to explore.

"That level had a lot more work done on it than any other level," Romero said. "It wasn't bigger than E1M7, but it did have a really huge secret area, which is that big maze. What I wanted to do there was to show people that when you find a secret, it's not necessarily a little room or something necessarily inconsequential. It could be a huge chunk of the map that could be even more fun to play than the [main] part."

Far back in the maze is a short corridor where a light fades on and off. Players turn a corner into the hallway and are accosted by a pair of Imps. Panicked, players fire blindly—and then, above shrieks and grunts, another telltale creak of a panel sliding away.

"You're going to be shooting," Romero said, "and I was hoping a stray bullet would hit a wall and that would cause it to open, and you'd be like, 'How did that happen? It must have been me shooting the wall.' That was another, 'Wow, you can do that too? This is a secret inside of a secret.' E1M2 shows, here's a secret that's bigger and cooler that's bigger and cooler than any secret I've seen before, and here's a secret within a secret to get a really cool weapon."

Past the false wall and up a set of stairs, players emerge in a (mercifully) lit room with a pillar. Atop the pillar, lowered by a switch, rests a chainsaw, marking the first appearance of the iconic weapon. Set in the wall beside the pillar, a window looks into a closet-sized room inhabited by an Imp. Players grab the chainsaw, find their way out of the maze, and head up the curving stairs. Less than halfway up, they may notice an alcove on the left. Stepping into it causes a lift to drop them into that closet-sized space, where the Imp greets them warmly.

E1M2: Secrets within secrets (within secrets).

That closet serves a dual purpose. If players didn't know about the chainsaw before, they can drop into the closet and look out into the chainsaw room. "Secrets are just so cool," Romero said, laughing. "We carried them into Commander Keen and into Wolfenstein, but they were barely in Wolfenstein. We decided that in Doom, it would be secrets everywhere. Then it became a checklist item: do you have four secrets in your level?"

Is four secrets too many? Romero doesn't think so. In fact, depending on the size of the level and where designers plant them, four might not be enough. "I think you have to think about, Is that really a secret? If there are so many secrets, does this one really count, or is it expected?"

E1M2's nest of secrets gave Romero plenty of opportunities to finetune his approach to deciding when, where, and how to hide them. "They mostly [were signaled by] a texture that seemed out of place or different," he explained. "There were still secrets that you couldn't tell, just to make them super secrets. The secrets we wanted people to find, we made sure there was a visual difference. In Wolfenstein, we had that sometimes, but it wasn't consistent. With Doom, we were trying to be more consistent with how we placed secrets."

Signs hanging askew or textures that don't quite match provide tacit instruction to players. However, teaching players to look for secrets and venture into side areas was equally important. Each and every off-the-beaten-path region in Doom's maps contains items of value: health packs, ammo boxes, armor shards, or—the prize among prizes—a new weapon.

Sprinkling power-ups was an assignment Romero and other designers approached by making sure that players came out of optional paths better than before they went in. E1M2 drives this lesson home in spades, from the dark and claustrophobic maze that rewards inquisitive players with a chainsaw, to another secret-inside-a-secret, a spacious courtyard where Sergeants protect a chaingun and a Soul Sphere that adds 100 to the player's health.

"One of the things we did when we were balancing and designing games was every level was designed with a pistol-start in mind," Romero said. You should be able to play and finish every single level in the game if you start with the pistol, because if you die, you're going to start back with a pistol anyway. So what we did a lot of times is put some powerful stuff sometimes near the beginning of the level. If you find it, then you're going up to the proper guns for the area you're in."

Back for More

id Software followed Doom with Doom 2: Hell on Earth in 1994. By 1995, Romero and the others felt compelled to go back to the original and add fourth episode, Thy Flesh Consumed, to exhibit the design skills they had refined while working on Doom 2.

Late one night, Romero sat down at his NeXTSTEP and booted DoomEd. He was in charge of building E4M2, and had the perfect level flow in mind. "First of all, Episode 4 was supposed to be expert level, the hardest episode," he remembered. "American [McGee] opened with a really great map that was so cool and difficult, and I thought, This has to follow that and get everybody used to: 'this is some hard shit.' I decided to say, 'I have six hours to do this.' I started at midnight because I do my best work at night. I got done at 6:00 a.m., and the whole map was [imagined] in the editor as I was playing it."

E4M2: Open fire, or wait and bait?

E4M2 begins by dumping players into the proverbial frying pain and all but throwing them into literal fire. Two Sergeants march in place, facing away from players. Opening fire is ill-advised: Across the level, Imps fling fireballs and Cacodemons spit wads of lightning. Players have a few ways to proceed. They can race forward, but the Sergeants are sure to notice. Another option: sit back and wait. Doom's enemies are notoriously quarrelsome. Cacodemons and Imps will throw their projectiles even if players are standing right behind a Sergeant. The zombie will get hit, rightfully and royally pissed, and respond in kind.

Whatever they decide, players must act fast or get roasted in the line of fire.

"I was scoping it while I was making it," Romero reflected, "and thought, This is as big as it's going to get; I can't get bigger than this. It's a relatively small map, but it's hard to get through. American started his level quiet. It didn't start out with explosions, so I wanted to start my level with action happening right now."

E4M2 breaks down into four parts. Beyond the starting platform, players breach a chamber on the left where they have to raise a floor to create a winding staircase leading up to the top, where a Baron of Hell guards a teleporter. Far to the right are white walls mottled by pulsing cracks of lava. All the way across the level, a final platform hosts a Cyberdemon, lying in wait for players who run blindly toward the exit nearby.

Progression necessitates risk. E4M2 is like a house on stilts, all of its architecture perched on pillars and platforms high above a burning floor that saps their health.

"You can see the end from the beginning, but you can't get there yet," Romero said. "You've got to go through these side areas before you can get to the end. It's hard to run and jump and not fall into lava. There are little, tight turns, and immediately a Baron of Hell in the next room, and a Cyberdemon up on top, and there are Cacodemons all around in this small space, and you're trying to solve a puzzle and just not die."

By the time they completed it, most players likely agreed that E4M2 had earned its proper title, "Perfect Hatred," a hundred times over.

"For the original Doom, some of the names came from Tom [Hall] coming up with initial names: the Hangar, Command Station. Those are Tom's names," he remembered. "Episodes 2 and 3 was Sandy Petersen naming those: Mt. Erebus, Phobos Anomaly, and all that. For Episode 4, [artist] Kevin Cloud came up with a big list of things we could name from. He thought it would be cool if we had these biblical [phrases] we could pull from. 'Oh, Against Thee Wickedly? Hell yeah!' I thought that was cool. I loved 'perfect hatred,' so those were my two levels."

It took John Romero six hours to build E4M2. Twenty-two years later, feeling the urge to brush up on his level-design skills, he sat down to build an alternative to Doom's E1M8. "I chose that level because I didn't make the original E1M8; I asked [designer] Sandy Petersen to make it. We were getting near the very end of the project, and I didn't have that much time, so he did it in a day or something."

Dozens of more advanced games and editors had come and gone since Doom's heyday. Romero would have used one had he felt so inclined, but for him, Doom's toolset was the path of least resistance. He still knew it—he would always know it—and it would let him bypass the slow process of learning new tools and cut straight to building maps.

Romero designed his alternate E1M8, "Tech Gone Bad," as the inverse of Sandy Petersen's. Petersen's level was dark, moody, and punctuated by a battle against two Barons of Hell—a sort of final-boss encounter that put a bow on Episode 1, which id gave away for free as shareware. Romero's map is more open and crowded with enemies.

"At the end of the game, for me, I wouldn't want the game to end, but it's cool that the end level is so huge and fun to get through," said Romero. "When you're done with it, you'll feel like you really went through something—although the original E1M8 might have helped sell the game more; it ended so quickly and you were left wanting more."

Romero's E1M8 was even more frenetic than E4M2. Unless players append it to their Doom version of choice and build up their arsenal by playing through Episode 1's preceding levels, they'll set foot in Romero's E1M8 carrying only a pistol and the Doom marine's hairy fist. The trick, Romero explained, is to get to a safe place, pick off a Sergeant, steal his gun, and then weave in and out of cover, sniping monsters and looting them for ammo.

It's doable, but barely, pushing id's pistol-start mission statement to its limits. "I figured that by this time, people are really good. If you start out and go to the right, then go left around the candelabra in a room, you're basically not getting hit by any fireballs. You just pick off the guys, then you run over and pick up a shotgun and blow everyone away. You can do it without getting hurt much, but you have to stand behind that candelabra. Otherwise it's open season."

In honor of his comeback and his trademark Midas touch on 'Tech Gone Bad,' Doom World awarded John Romero its first physical Cacoward in 2016.

Defeating John Romero

Doom 2 shook up its predecessor's formula by adding nearly a dozen new monsters, the fan-favorite super shotgun, and 30 maps divided into episode-sized chunks. Though it contained its share of space stations and dens of hell, its earth-themed levels channeled the original game's abstraction. Doom 2's cities consisted of futuristic buildings arranged in urban sprawls that bear only a passing resemblance to realistic environments.

Setting aside hidden mazes and chainsaw rooms, the original Doom's progression broke down to a simple formula. Find colored key cards, unlock doors, rinse and repeat until the level ends. Romero and other designers at id baked Doom 2 with that same recipe, but from new angles.

"You don't want to do the same thing over and over again," Romero said of Doom 2. "It always comes down to keys and locks, so how do we do that but represented in a different way so the game is not just more of the same thing. It needed to feel like there was some extra element in there."

Map 11, "Circle of Death," is one of Romero's contributions. Players begin on the outskirts of a circular platform, and solving the level calls for players to explore smaller rooms adjacent to the ring.

"Off of that ring, going out and exploring," said Romero. "That's the progression: going out from the center in different ways, coming back, and going out again. I think people understand: you get to the end of a little era, and there's nothing else to explore so you've got to come back to the middle. Then you see, 'Oh, I've got that [key] card.' You kind of know the next step is somewhere from the center. I thought it had a pretty good progression."

Doom 2 Map 11: Not only can the Arch-vile roast you with hellfire from afar, it resurrects dead enemies in its path.

At a certain juncture through Map 11, players will enter a courtyard identifiable by two gnarled trees to either side. Stairs hug the walls, and heading up either set deposits players near a cage that springs up to reveal the Arch-vile, one of the game's new monsters and arguably its deadliest thanks to its ability to resurrect slain enemies.

"We didn't actually plan which level the Arch-vile would be in," Romero said, "other than that he's probably going to come in somewhere around halfway through the game because he's a pretty powerful guy like the Revenant is. I put him up there because it made sense to keep him constrained to a room and not just running around resurrecting the whole level as you ran away from him. I thought that was a good way to keep him in a cage."

The approach leading to the Arch-vile is one occasion where Doom 2 plays to its roots in action-horror design. By Romero's admission, Doom 2 leans into action and exhibits far fewer horror set pieces and levels than the original. That was a product of id listening to its fan base. Most Doom players favored nonstop action, so the developers gave it to them.

Still, Romero enjoyed punctuating Map 11's otherwise frantic combat by springing the Arch-vile on unsuspecting players. Trigger-happy players could make the encounter more difficult by accidentally shooting at the demon from below, waking him up and causing him to emit his throaty growl.

"You think, What is going on? Then you get up there, it's a dark room and there are other monsters, and there's fire everywhere. It's really scary. I thought it was really good because you're that hallway and room are hard to move around in."

Doom 2 Map 20: Goliath versus Goliath.

Map 20, another Romero special, is Doom 2 twist on a gladiatorial arena. Through the first door, players set foot in a vast hall. Go in a little further, and two wide platforms descend from the ceiling. A Cyberdemon stands on one; on the other, a Spider Mastermind shrieks upon setting eyes on players. Both bosses unload. Players can fight back, but in this instance, movement proves more effective than shooting. Sprint behind one to put it in the other's line of fire, and within seconds the bosses redirect their fury and firepower on each other, leaving players free to flip a switch and escape to the next room.

"The idea is to learn that room as fast as possible, and even better, getting around them while they're fighting each other to flip that switch, which is crazy," said Romero. "The trick is to make them start fighting each other because I don't want the player to get attacked by both of them. It was a big deal to make sure they're fighting each other, and you get to witness some crazy stuff, and you can't get out of there unless you go to where they're at, so it's even scarier. There are all sorts of ways you can handle it, so I thought, Let's see what the player decides to do."

Map 30, the final stage, was not created by John Romero, but his presence is felt nonetheless. Kevin Cloud got it in his head to play a prank. He whipped up a likeness of Romero's severed head—flowing black mane and all—and stuck it on a bloody spike, then stashed it behind the towering Icon of Sin, Doom 2's final boss that spans an entire wall.

Cloud figured most players would never notice. Clipping through walls was only possible if players typed in a cheat code, and even then the Icon's onslaught of attacks would distract players from even thinking to ghost through its vulpine face to see what, if anything, lurked behind it.

Romero was not most players. "I found that out accidentally, when I was hooking up audio. I saw my head was there. There's no reason to have a graphic there because no one would ever see it, so when I saw my head there I immediately knew they were trying to sneak in an Easter egg... but in a non-obvious way."

Doom 2 Map 30: oremoR nhoJ ,em llik tsum uoy ,emag eht niw oT.

Romero loved Cloud's Easter egg, and thought of a way to one-up him. If his head was in the final boss, players were, in essence, attacking him; the Icon of Sin was a mask to disguise the player's true adversary. "So to win the game, you have to kill me, not the Icon of Sin," he reasoned. "Maybe I am the Icon of Sin."

He went to Bobby Prince, the game's composer, and ran an idea by him. Romero would speak the line To win the game, you must kill me, John Romero, and then Prince would work his magic. "I told him, 'Okay, we're going to record this, then pitch-shift it down and reverse it. It's got to sound evil.' He did all of that really quickly and it sounded amazing, so I stuck that in for when my head sees you. It makes that sound on first sighting, and it sounds like this big evil thing on the wall is talking to you, and it just sounds [terrifying]."

Now it was Romero's turn to stifle laughter. He had turned the tables on Cloud by staying mum on the fact that he knew about his buddy's prank. All he had to do was wait for the game to be released, and some player would hear the boss speak and deduce that it had been played in reverse. Word would get out, and Cloud would realize Romero had known about his bloody head all along.

"But the very next day after putting the sound in there, American McGee comes into the office, heard it, and went, 'Oh, backwards scary thing? Let me reverse it.' Then we told everybody and it was over, but we left it in because it was funny."

Play Tests

John Romero's excitement over breakthroughs that occurred during the original Doom's development are the stuff of gaming legend. The most famous anecdote was the day John Carmack tested his network code by running Doom on two computers and entering a deathmatch. Pressing a key on one keyboard, he turned to look at the second monitor and saw his first character moving around. Romero nearly exploded with excitement and sat down to challenge his programming cohort right then and there.

Then there was the time Hall and Carmack surprised Romero by remaking the first level of Super Mario Bros. 3 for PC. The demo, which substituted Romero's Dangerous Dave character for Nintendo's plumber, incorporated code that Carmack had written to scroll the screen smoothly to the right—a technical feat Nintendo had popularized on NES, but that had to date been thought impossible to do on computers.

At the time, Romero and the others worked at Softdisk magazine writing games for the publication's monthly demo disk. Romero took one look at Hall's and Carmack's demo—appropriately titled "Dangerous Dave in Copyright Infringement"—and declared that the demo was too good to share with the magazine; it was time to start their own company. A short time later, id Software was born, and their first game, a 2D sidescroller called Commander Keen sold according to the shareware strategy pioneered by Apogee founder Scott Miller, put the fledgling company on the map.

From left to right: John Romero, Kevin Cloud, Adrian Carmack--no relation to John. (Photo credit: John Romero.)

Romero looks back fondly on those and other anecdotes. But there's another standout moment, one he was fortunate enough to repeat dozens of time while designing Doom.

"There was a point when I was playing—I believe this was after Sandy [Petersen] got on board; maybe late August or early September—and there were these levels that he's been making, and I haven't seen them before. I got to play them. I'm playing the game and I don't know what's going to happen because these are levels I haven't made."

It's a rare treat for a programmer to be surprised by his or her own game. Even if they did not design a certain weapon, monster, puzzle, or level, they know the code. What goes on behind the curtain holds no mystery to them; they are the wizards, and the game casts the spells they commanded it to perform.

"You hear these sounds echoing in the background because you activated monsters and they're wandering around in the dark," Romero continued. "Then I could tell how scary the game was going to be because it was a level I hadn't made. I knew the code, but those monsters were doing unpredictable things as far as I was concerned. That was really cool: to feel a little bit of what people were going to feel even though I was used to playing the game. But if I could feel that at that point, when we were almost done with it, I knew it was going to be pretty great."