Read an Excerpt from ‘The Bitmap Brothers: Universe,’ on the Creation of ‘The Chaos Engine’

All 'The Chaos Engine' screenshots and Bitmap Brothers concept art courtesy of Read Only Memory.

Waypoint is pleased to present an excerpt from The Bitmap Brothers: Universe, written by Duncan Harris and published by Read Only Memory, with design and editing by Darren Wall. The book is, to quote from the publisher's website, "a comprehensive history of the visionary British software house". I can confirm: it's a very big book. And it smells really nice, too.

Long story somewhat shorter, though: The Bitmap Brothers, based in Wapping, were amongst the most celebrated designers and developers for the Commodore Amiga and Atari ST. Many of their games, such as the sci-fi sports sim Speedball 2: Brutal Deluxe, the stunning-looking action-platformer Gods and the vertical scrolling shooter Xenon 2: Megablast, also found homes on other 8 and 16-bit platforms.

I played pretty much everything they put out for the Amiga, and perhaps with the exception of the rather rote platformer Magic Pockets, loved the lot. (I previously wrote a little something about the studio for VICE, here.)

We've a (substantial) section below from the chapter "Split the Difference: The Chaos Engines", focusing on the creation—the concept, the design and the brilliant music—of one of The Bitmap Brothers' most famous games, The Chaos Engine. A top-down arcade-style shooter, The Chaos Engine went deeper than many a coin-cruncher down the local pier or high street, offering six different characters to choose from, and AI-controlled co-op play that didn't have you tearing your hair out. It was definitely a lot more than a Gauntlet rip-off with a steampunk twist.

I played it a bunch with my brothers, but always got further into the game without human help—which I guess is an endorsement of just how excellent that drone companion could be (or how awful my siblings were at video games).  -MD

Even in the mid-19th century, there was debate over the role of Charles Babbage's mechanical computers in the field of cognitive science. Some talked it up, Lady Byron declaring his early Difference Engine a "thinking machine." Others likened human reasoning itself to the operations of his second, unbuilt Analytical Engine. Babbage preferred industrial and economic thought, identifying a tier of worker who might be replaced by such automatons. All of which begs the question: how do you program a human?

It was a different The Difference Engine which caught the imagination of (Bitmap Brothers designer) Phil Wilcock in 1990, just prior to finishing (the isometric adventure game) Cadaver. The novel by William Gibson and Bruce Sterling, an early example of steampunk, posits an alternate-history Victorian Britain in which Babbage's engines weren't just finished, but revolutionary, creating a graphic landscape of analog science fiction.

Sensing potential for an action game milieu, Wilcock shared his enthusiasm with his neighbor at The Bitmap Brothers, (artist) Dan Malone, who admits: "I started drawing it immediately. Sketches and characters. I was supposed to still be doing Speedball 2."

Wilcock's The Chaos Engine is pure HG Wells next to the political machinations of the novel, casting Babbage as Baron Fortesque, an inventor whose eponymous thinking machine can also manipulate time and space. Sure enough it becomes self-aware, instantly goes mad, and wreaks inter-dimensional havoc on Britain's towns and countryside. When even the nation's cats start turning into warbling cacodaemons, six hired guns are called in to basically shoot the world right again.

Steampunk wasn't officially steampunk yet, and this proved quite hard—and in hindsight amusing—to explain to people. "If there'd been a nuclear apocalypse in the Victorian age, this is what it would have looked like," attempted Malone in one interview. (Bitmap Brothers co-founder) Eric Matthews described it looking "like the inside of a 1920s oil liner." (16-bit focused British games magazine) The One called it "Upstairs Downstairs meets Rambo."

Matthews, naturally, was excited by the mechanics beneath all the pipes and valves. Here again was an arcade genre, known for games like Gauntlet and (1989's Sega-made) Crack Down, "that has never been done particularly well, especially on home computers," he said at the time.

"It's become clear that the simple idea of running around killing monsters and nothing else is simply not enough. You have to have that extra element of discovery that allows you to go back and experiment, and find new things each time you play—that's what makes a good game."

It was decided that The Chaos Engine should inherit much of what made (1991's Bitmap Brothers-made action platformer) Gods so successful: a sense of intelligence not just behind the game, but within it. Not just alcoves, loot, progression and consequences, but something truly unpredictable. The CCP (Computer Controlled Player), as it was known, would ensure that even solo play had the dynamism of co-op. Regardless of how many people were at the controls, there would always be two players.

Passing that particular Turing test remains, says (designer) Simon Knight, "a phenomenally difficult thing to do." It's why practically every multiplayer arcade game holds out for someone to "insert coins" or "press start," and why they seldom feel as comfortable in one mode as the other. Levels built for one feel crowded with two, and vice-versa. But The Chaos Engine, with its fixed player count, could be designed with greater precision.

To pull it off, though, the CCP would have to emulate not just a real person, but six personalities: Brigand, Gentleman, Mercenary, Navvie, Preacher and Thug. Malone had designed nine initially, and lists "a Victorian lass and a guy with a fencing mask" among the three that missed out. Each had its own characteristics, the Preacher's treachery—put simply, he'd nick everything—earning him a new name, the Scientist, when the game was released in America.

Whatever this says about the trust issues of secular Britain versus the US Bible Belt, faith in the CCP was squarely a question of science. Its own Baron Fortesque, then, was self-taught programmer Steve Cargill, a colleague of the Bitmaps' Sean Griffiths at Softek. His pre-Bitmap work included Garfield games Big Fat Hairy Deal and Winter's Tail. He coded almost all of The Chaos Engine himself.

"A design was already there when I started," he recalls. "The Chaos Engine very much wanted to be a two-player game, but you had to be able to play it on your own. The AI had to be invisible to the real player, so you'd have the same experience as if you were playing it with mates."

Even by Bitmap standards, this required an unusually high level of interaction between designers, artist and programmer. In other words, better studio tools. Still using SNASM to compile and debug, the studio's PCs were now equipped with Super VGA graphics cards capable of high-resolution text, giving Cargill a much bigger window on his code.

Montgomery had also written macros for American Cybernetics' Multi-Edit, a powerful source code editor, giving it a rudimentary form of version control (a system which tracks changes made to code over time). "Everyone had an ear into what other people were doing," says Cargill. "It was a very creative world, and by far the best programming environment I've ever worked in.

"Mike had some fantastic code for doing Amiga graphics: the screen handling and sprite routines. That went into The Chaos Engine pretty much as-is, but because it was slightly older code from other games, we'd tweak it and develop it. But it meant we didn't need to start from scratch. We might not have had the big libraries the people use these days, but we had the core of that, and an idea for it."

Much of Cargill's early work on the game, in fine Bitmap tradition, was spent on editors. A designer on the game could do a whole lot more than just blocking out the levels and laying down puzzles. Music was cued and modulated through the level editor, while a scripting language gave high-level control of the game's systems. "We wrote all of this to allow the design to be as efficient and flexible as possible," he says.

Malone's tiles for the game, drawn from the same perspective as Speedball 2: Brutal Deluxe, but now at multiple elevations, are so varied that it's hard to believe the levels were designed using just two block types, described by Knight as "the bits you could walk on, which were one color throughout the level, and the bits you couldn't." If there was a particular landscape feature, such as stones arranged in a helpful arrow, Knight would draw it and show it to Malone, saying: "I've put that there deliberately, so leave it." It was never contentious, he insists, but there was a lot of "backwards and forwards."

This, Malone confesses, means "I changed shit around all the time." Knight would sweat over gameplay issues such as chokepoints in the terrain, Matthews would rubberstamp his layouts, and Malone would then decide that "a nice waterfall wasn't being introduced properly or something," and start fiddling. This would often mean more tiles, and Malone made so many in the end that the game was effectively full. The tiles used so much disk space that when it came to making a finale screen, all that would fit was Baron Fortesque's face on black.

"That's properly all we had left," says the artist, who considers The Chaos Engine the best tileset he's ever done. His mood sours in the telling, though. "It was the last time I had fun making a game, too."

Many a fan of The Chaos Engine will be oblivious to how good its AI is—because that's how good its AI is. AI is the science of the mundane, after all, the realism upon which fantasy is built. You won't believe a man can fly if he can't walk from A to B. A world driven mad by an omnipotent machine doesn't work without a bedrock of sanity. That's the CCP.

Malone's characters, proportioned like early '80s M.U.S.C.L.E. action figures, were anything but realistic. "The feet are about 16 pixels apart, and you build the body off of those," he explains. "Their hands are huge because they have to be. The recoil on their guns is about a foot in relative human terms, it's massive."

Their actions, though, had to be thoroughly unremarkable. Smart and yet clumsy like a human could be, not a robot, as Cargill explains. "We didn't want the computer to be able to run ahead and solve everything, so it was very much controlled by you. He'd be fully autonomous, but in a way we'd be patting him on the back, pointing where he should go."

By distilling the speed and thoroughness of the game's pathfinding systems into simple parameters, Cargill let the designers control how a Thug or Brigand should act. "Some characters could see further, some were limited in what they could see, and one might see further but be a slower 'reacter.'"

Making these characters into virtual players was a whole other ball game, of course. The Bitmaps had devised a test: someone would sit in a room playing the single player game while people watched the screen, trying to figure out which character the player was controlling. Getting to a point where they couldn't, explains Cargill, meant "fuzziness."

At its heart, The Chaos Engine never actually knows who's controlling player two. Higher-level functions create fake joystick inputs which are then passed to the core AI systems. This meant Cargill could design the CCP in strictly human terms, basing its behavior on how people visibly play. "He's never boring," he says. "He doesn't just sit there banging the button."

In this context, fuzziness is what a player does when they should be doing something else. It's the zag when they should have zigged. So, if the game's pathfinding system decided the CCP should head north, Cargill might tell it to head north-east for several paces instead, then re-evaluate its position. "Suddenly, it wasn't always doing things the same way," he says. He'd taught it to make mistakes.

"We did things like keep the CCP moving as he shot, allowing a little bit of spread of the bullets: more chance of hitting, more chance of missing. Sometimes his angle was off. If there's four or five enemies and the CCP's being shot at, the game logic might say: move left, and with the next step move right, so he just sits there jittering. It could move him far enough away that his next move probably isn't to go back to where he was; the monsters will have moved, the bullets will have moved."

That same impulsiveness was applied to the game's enemies. Starting in a patrol mode as you entered a particular area, they'd respond to triggers such as a door being opened, shots being fired, or an item being picked up. How they responded would vary. They might attack, patrol differently, or go on the defensive.

By littering these processes with pauses—hesitation, in human terms—Cargill gave the system room to breathe. More could happen in between thoughts, making even simple encounters unpredictable. It proved so central to how the AI behaved that 'Intelligence' became the only upgradeable character trait alongside basic "Strength."

The CCP was becoming so capable, in fact, and convincing, that it created a new kind of problem: "Once you had one of them," says Cargill, "you could very easily put that AI through another one." This is why, when The Chaos Engine made an early public appearance on Channel 4's GamesMaster, it didn't have two players, but three.

Looking at the segment now, it's hard to know what's more conspicuous: the extra CCP running about, or the sight of (Bitmap Brothers producer) Graeme Boxall having a kind of Colonel Kurtz moment, his shaven head protruding from a darkened room as he hurries through his PR lines, trying not to look at the camera.

"I'll tell you about GamesMaster," he says flatly. "I'd been to a nightclub about two nights before, and someone lit an amyl nitrate cigarette and stuck it in my mouth, and it effectively burned my face off. The tip of my nose was gone. But Eric wouldn't do GamesMaster—he insisted I did. I'm not a PR person at all, so it was just the most horrific experience." He thinks for a second. "Why would someone do that? When you looked like that?"

Boxall's nights out didn't always end in disaster. The Renegade connection (Renegade being the Bitmap Brothers' publishers) made the Bitmaps regular guests at (the Renegade-founding dance music label) Rhythm King parties, and it was there that he met brothers Farook and Haroon Shamsher, known on their records as Joi. Born in Bradford and raised in (London's) East End, the Shamshers grew up watching local Indian musicians perform in their father's makeshift studio, built above his store selling saris and imported instruments.

Over time, their cultural roots would fuse with hip-hop and reggae, and in 1983 they began DJing in (London's) Brick Lane nightclubs as the Joi Bangla Sound System. These Asian collectives broke out during the early '90s, their dance-infused Banghra sound a hit with the national music press. The Joi discovered by Boxall had just put out debut track "Desert Storm," receiving NME's Single of the Week ahead of runners-up Nirvana and REM.

"We were living at (Rhythm King founder) Martin Heath's house in Kilburn at the time," recalls Farook Shamsher. "We had a studio on his top floor. I'd bump into Graeme now and again in nightclubs, and we were all East Enders in a way. They invited us to their offices one day, and we started off just hanging about."

A mutual admiration developed. "We were trying to be quite creative and special within our genre, in whatever we did. Coming from the Asian sound system was about breaking barriers. We'd been buying hip-hop imports for ten years; it wasn't just an Asian thing, and I think The Bitmap Brothers realised that.

"They gave us a spec for The Chaos Engine, this idea of the person who first invented computers. We loved that it was old-fashioned—and quite Celtic, which we related to, being Asian as well. So yeah, why not?" Boxall recalls: "I went to Martin's house with DJ Mrs Wood, and the Shamshers just took loads of samples all day. It was never really discussed, they just did it."