The story of how Boulder Dash was created

We spoke with Boulder Dash creator Peter Liepa about his classic action-/puzzle game.

If you were even remotely interested in computer games back in the eighties, chances are good that you’ve heard of Boulder Dash. This arcade style game became an instant success when it first released in 1984, and thousands of players all over the world became hooked on its smart combination of action and puzzle solving.

In Boulder Dash, you play a creature called Rockford, and your goal is to dig your way through sixteen underground caves in search of diamonds. But these caves are also full of loose rocks that threaten to squash you if you’re not careful, as well as enemies that can be avoided or exploited.

Boulder Dash is an entertaining experience even today. It’s one of those games where a number of dynamic gameplay mechanics combine to create a deep and engaging experience, even though the individual elements are by themselves pretty simple. It’s also a much more player-friendly game than many others from the same era, designed with the goal of providing an enjoyable experience instead of constantly beating the player. Although we wouldn’t say it’s easy, either…

The Boulder Dash name might not be as well known today as it once was, but the series is still alive and we’re currently awaiting a brand new Boulder Dash game this summer. Fittingly, we’ve had a long talk with Peter Liepa, the Canadian developer who created Boulder Dash back in the early eighties. We spoke with him about everything from how he first got into contact with computers to his ideas behind the level design.

So get yourself a cup of coffee or something equivalent, and prepare for a deep dive into the history of one of the true classics of the eighties.

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An early introduction to computers

Joachim Froholt: How did you get into computing in the first place?

Peter Liepa: As a kid, I was interested in mathematics – and I was good at it. But I was born into the world of mainframes and punchcards, and calculators as big as toasters. So, computers were not something in my childhood at all. When I was a kid, they were just big machines that were only found in businesses or in movies. There was no way to really learn about them, other than by accident.

But my father was a doctor at a hospital, and I remember he was talking about a small computer they had bought there to automate various tasks. In hindsight, it was kind of ridiculous, because it was a laboratory computer. But he brought home the manuals, and I read them – not too intensively, though. So there were ways, I suppose, if you looked for it, that you could learn about computers and programming languages.

The first time I actually touched a computer and was able to write some software for it, was during a high school program in the spring school holidays. We could go to various institutions, and I chose the National Research Council, which is a scientific institution in Ottawa that was in charge of research for the Canadian government and industries. In those days I wanted to be a physicist, so I signed up for a physics lab and I thought this was going to be very exciting. I went in on my first day, and that was when I saw my first calculator, which was the size of a typewriter (or a home computer today).

I played with that for a while, and was reprimanded for wasting my time with this toy. What they really wanted me to do was to drill holes into metal sheets so they could build some apparatuses. I went along with it, realizing this was not going to be a lot of fun, but on my second day there we were given a tour of some other spots at the National Research Council, that included a computer lab. This is where I fell in love, I suppose. And I asked to come back.

I was given leave from the physics lab, because they realized I was absolutely not interested in drilling holes for them. Instead I was allowed to go to the computer lab, and one of the staff there very kindly took me under his wing. He showed me a teletype terminal and gave me a little information on programming, including a manual which I read. I came back the next day, having written my first program with pencil and paper the previous night.

A few years later, I went to university where computers were accessible, usually through teletype terminals. You would type in commands in a language called APL and get the results. And I burned up lots of university printer paper doing that – implementing Conway’s Game of Life, for instance, and printing out 600 generations of that would go through paper fairly quickly.

Not having learned my lesson about physics, I had enrolled as a physics major. But I quickly found that was not for me, so I retreated to mathematics which was always safer for me, and easier to do. I also added some computer science courses. So in those days you kind of picked it up. You could hone in and specialize, but to me it was like a side dish in my education. In those days computer science was also, I suppose, the easiest thing to get into, and you could always get a job doing this kind of thing. So, one always gravitated towards it.

JF: You mentioned Game of Life, which is more of a simulation, but did you play any actual games?

PL: Yeah, I was interested in games. In those days it was mostly board games that everybody knew, like Monopoly. But a lot of new gaming cultures were coming into existence, with smaller companies creating things like wargames with hexagonal maps where you simulate battles, and there were lots of games in that genre. That was the beginning of a whole games culture scene. Stores were opening in Toronto, where I was at the time, where you could buy such games. Dungeons & Dragons was, of course, a big thing.

I remember having a closet full of these old games that I bought. To be honest, I didn’t play most of them, because I didn’t have friends who were interested in doing that sort of thing. But yes, I was certainly a big fan of that games culture.

JF: Any computer games?

PL: Computer games started appearing in the early 1980s. I suppose Pong was the first computer game that had widespread availability in arcades. Late 70’s and early 80’s was when you would see video games in arcades. And you happily put quarters into these machines until you ran out. Then the home consoles and home computers came out. I was not an early adapter, but I knew somebody who was, who loved spending his money on electronics. This was also a fellow computer programmer. I would often join him and his friends on weekends at his place, and play games on his big screen.

JF: How did you start creating games yourself?

PL: One day standing in front of his big screen playing these games, I thought, «I could do this.» Why not? I guess I was kind of learning, there was a culture of video games and as you play enough of them you sort of understand the basic principles. I had computer programming skills, and a lot of interest in things like mathematics and using mathematics to create images. Fractals, for example, were another big movement starting in the late 70’s and into the 80’s. There were all sorts of recreational mathematics in the air as well. So there were all these things that I had been exposed to, like board game culture, the math and science, the simulations, even sound synthesis, since I played with synthesizers. And then playing video games…

So I was pretty well prepared to apply all that to start making my own games. I bought a computer and lots of computer magazines – in those days computer magazines were often very thick and full of program listings that you could just type into a computer and play with and modify for yourself. I, like probably tens of thousands of other people, learned how to use these home micro computers using these magazines, finding out how to create special effects and write little games.

Retrogamingpappa: What kind of computer did you get?

PL: I first bought a RadioShack computer called TRS-80. I played with that for a month, but ended up taking it back. Decided that was not for me. That’s the only one I remember getting before actually buying the Atari 800. I must have bought that because of Atari’s reputation for games, and the fact that it was probably the ideal computer for building a game. Because it came out of a heritage of games.

The creation of Boulder Dash

JF: The idea for Boulder Dash, how did that come up?

PL: Having been exposed to all these games – buying them, playing my friends’ games – I thought, OK, what am I going to do to write a game? In those days, the industry was still growing up. Small game developers and publishers were springing up all over the place.

I found out there was a local outfit called In-Home Software. I decided to approach them and said, «Hey, I think I’ve got the skills to write a game. Is there anything you’re interested in? Give me some guidance – what do you think the market wants? What is it you want to sell?»

Their reply was, «Well, we don’t know either. But we’ve had other submissions, and one in particular we think is promising. It’s from a kid who’s basically written a demo, but he doesn’t have the skill set to bring it into production. Maybe you could work on that?»

So they introduced me to Chris Gray, who was indeed a kid – at least compared to me. I think he was 15 or 16. He had written a game called Pitfall, which he didn’t really want to admit was a very close clone of an arcade game called The Pit. It involved a bit of digging, and evading rocks and enemies. Superficially it sort of sounds like the ballpark where we ended up in with Boulder Dash.

They needed someone who could take that and turn it into something that could be sold – something not written in BASIC. I figured I could spend a few weeks on it. This was my foot in the door to the industry, so we agreed I would go forward and try to make it marketable.

Unfortunately, I think I made the agreement a little too early. I sat down and played the game for real and thought, «there’s not much here that interests me.» At the time, no one really worried too much about cloning other people’s games. But it just seemed to me that the ideas Chris had put into the game weren’t resulting in very interesting gameplay.

I decided to more or less throw the thing out and rebuild the physics for the rocks to make it more fun. In Chris’s version, if you got close enough to a rock, it would fall,  but it just wasn’t very exciting. So I wrote something that was basically inspired by The Game of Life – conceptually similar, except instead of reproducing dots, you had the force of gravity.

This allowed me to have things like avalanches. It was really simple physics – not even really physics, to be honest. It was just: if a rock finds itself over empty space, it falls. If there’s more empty space below, it keeps falling. If it hits something, like another rock, earth or a brick, it stops.

It was a very simple model, and it probably only took a day or two to write. But once I had that, I could sit there for hours. I had a random number generator that would just scatter rocks and earth on the map, and I’d run the joystick through it, destroying earth and watching the rocks fall. Then I realized that, oh my god, this is actually kind of fun. It was like a kid playing in the mud; building little dams and letting water flow through. You had a toy to play with.

The more I played with it, the more I realized it led to a fun and addictive experience. Even if all you did was destroy earth and watch rocks fall, that was already entertaining. But then, I could also run into a dense area of rocks and try to make my way through the maze.

All of a sudden, it went from just mowing the lawn and clearing out caves to navigating a maze. Then I realized, if you have these little creatures that can be killed by letting a rock fall on them, that adds another layer. So from that simple beginning, with rocks represented as X’s and O’s on a screen, there was a fun element right from the start. It just needed to be refined into as many game or puzzle scenarios as I could come up with.

And they more or less wrote themselves. All I had to do was throw random stuff on the screen for inspiration, set myself little goals, and then try to achieve them. That got me thinking: How do I make the player go through the same thing? How do I expose them to those goals? Make them not only enjoy dropping rocks, but also want to achieve objectives.

That’s probably where the jewels came in. As bait, so to speak. Motivation to do something more than just play around. So, it more or less grew from there.

JF: One of the things that’s fun about the game is there are so many synergies between the elements.

PL: Yes, the synergy – that’s exactly it. It just kind of evolved. Honestly, it was just me messing around, finding enjoyable little puzzles that I could make up for myself, and then trying to embody those with other elements like enemies or creatures.

The creatures were really just drivers for the puzzles. They are very simple. The butterfly and the firefly are just squares that follow a maze. One of them is right-handed, the other left-handed. That’s all they do, they follow the maze. But of course, they also have a kind of power: if Rockford touches one of them, they explode. The butterfly, for instance, creates jewels when it explodes.

They’re all very simple, but you can imagine the evolutionary steps involved. The enemies were really there to drive the plot, but they also interact with each other. That’s the synergy – yeah, like when the butterfly touches the amoeba and everything turns into jewels. All these elements kind of feed off one another.

JF: Were the amoebas inspired by The Game of Life?

PL: I can’t remember any direct inspiration there. It’s not clear where it came from. Maybe The Game of Life, but also maybe The Game of Go, because to profit from an amoeba, the trick is that you have to surround it with rocks. You have to suffocate it. So, kind of like Go, where you kill off the enemy by surrounding it. Again, you have these kinds of abstractions – like «surrounding» – that found their embodiment in the amoeba.

RP: So this all came from you just playing around with the world you had made. Had you added sound at this point?

PL: I was probably working on sound here and there, but I don’t remember exactly when I introduced it. As I said, I had a background in sound synthesis, so the answer is yes – sound would have been in there.

Let me divert for a second. You know, I wrote this 40 years ago. I kept all the floppy disks. They sat in closets for years, untouched. I probably forgot everything I needed to even turn on the old Atari computer, which was also in the closet. If I stuck a floppy in there, I’d be afraid of damaging something, or electrocuting myself with that old piece of electronics!

But about seven or eight years ago, somebody offered to archive these disks for me. To transfer them to modern media so they could be used in emulators. So that was done. And until recently not much else had been done with them, but a couple of years ago, I managed to extract the old Pitfall game that Chris had written. I had always wanted to see it again, since I’d been talking about it for 40 years. I actually screencapped an MP4 of a play-through of one or two caves in that game.

Very recently, someone in Poland, who I’m now working with, reached out to me. He’s a researcher into an old computer language called Forth, which was being used back in those days and which I used to develop Boulder Dash. He managed to capture some of my early work, when everything was in black and white and much smaller. Rockford was a stick figure who wasn’t even animated.

So yes, I have a clip of that. It does have sound. I think I was probably experimenting with sound in parallel to all of this. Again, I had an interest in simulating things from nature, like the sound of flowing water or what different objects would sound like. I had a bunch of little sound experiments going on alongside the game, and those eventually found their way into the game, one way or another.

If I wanted the sound of a rock actually falling and colliding, I knew how to build that. So, long story short, yeah: I have a one- or two-minute clip of an early, black-and-white, low-res version of the game. It’s rough, but it includes sounds like the amoeba sound and the rock sound.

So everything was sort of going in parallel. But it was a long process. You know, this rock had to be polished and polished and polished. It started off, well… I don’t know if you’ve ever seen a storyboard for an animated feature, where it’s just a series of still sketches. It looks nothing like the final movie. And in fact, making an animated feature usually involves hundreds of people working for two or three years, filling everything in.

Now, obviously Boulder Dash wasn’t that massive a project, but it followed a similar kind of process. It started from very crude – well, I wouldn’t call them sketches – but very basic implementations. And those were refined, over and over and over again. The main criterion was whether I liked what I saw. Whether it was interesting enough to keep me from getting bored and throwing the whole project out.

Adjusting the game

JF: Did you involve any game testers?

PL: I was able to rent a desk in an office space where some friends of mine were running a computer consulting firm. I didn’t really want to work at home by myself, as I knew I’d just end up watching TV all day.

So I got this space with friends and colleagues in software development. They went about their work, and I went about mine. But they were curious – actually, one of them was the same person who originally had the game console I’d played on at those game nights. So he was always interested in trying things out.

I wouldn’t call them «game testers» exactly, but I did get feedback. I observed their experiences, saw if they had any difficulties, and tried to address those. But they weren’t playtesting eight hours a day or anything. Mainly, I was the playtester. I was designing the game to satisfy myself.

That said, I did use other people’s reactions as a kind of barometer. I didn’t want anyone to get stuck or frustrated too easily. I wanted the experience to flow for everyone.

JF: So how long did the whole development process take?

PL: I think it was about six months in total. I probably started very late in 1982, and by the summer of 1983, I was more or less finished. I mean, «finished» in the sense that the game was playable, and most of the graphics were in place.

At that point the game was finished enough to start showing to publishers. And the only publisher I seriously contacted was First Star Software, because they were in New York City and I was in Toronto. Communication, even between two cities 500 miles apart, was a bit of a hurdle. Long-distance phone calls were expensive.

But yes, it was finished enough to show them, and they liked it. The changes they requested afterward were fairly minor. They wanted a really easy cave to start with. We called it the «Granny cave». The idea was that even your grandmother could pick up the joystick and make her way through it without much trouble. Or at least be challenged but eventually succeed.

They also wanted some small «intermission» caves, little bonus levels between every four caves. They might have also asked for some different color palettes, things like that. But those were all relatively minor tweaks.

JF: So, the final game was published by First Star Software and not In-Home Software. What happened with them?

PL: My memory is foggy on this. They were interested in publishing the game but somehow, despite my urging, were not showing any engagement or progress in developing a publication agreement. Perhaps I jumped the gun, but I began looking for other publishers. When I told them I was negotiating with First Star they were quite upset, but by then it was too late. And in hindsight, they might have been going out of business because I’m not aware of any titles that they published after this.

RP: How many caves did you have ready when you went to First Star?

PL: All of them… I’m guessing. I’d like to say sixteen, but that’s probably not true. Probably around ten. I mean, I don’t think I had any notes about creating more caves at that point. Creating caves was pretty simple by then. I had already come up with a format for defining them, so it was just a matter of inventing new cave concepts – which, again, I found pretty easy to do.

JF: It’s nice that the game has this mix of larger caves, smaller caves, and caves where the solution is more open. Some of them really make you explore or figure things out in your own way. It’s a good variety.

PL: Well, thank you. I appreciate that observation – and yes, that was absolutely my intent. I wanted to appeal to as many people as possible and leave things rather open.

JF: You mentioned earlier that you started out with random caves but moved away from that…

PL: Well, yes and no. Looking at the cave behind your colleague, for example [RP is using a screenshot from Boulder Dash as a background], my thought would be, you know, that’s random. A random array of rocks is basically good enough and right for the game.

All I had to do was tweak things like the number or density of rocks. And if I didn’t like a particular random configuration, for instance if it made the cave impossible to solve, then I’d replace it. But otherwise, the random results were usually perfectly usable and in the spirit of the game.

If I wanted something more specific, I’d build that cave explicitly. So randomness ended up being not just a tool for getting started, it became part of the game’s DNA. It saved me from having to design every cave by hand, and it helped shape the feel of the game overall.

It’s funny, I’ve thought about this in comparison to modern games like Candy Crush. Even though each level has a fixed layout or tableau, the specific arrangement is randomized every time you play. At first I thought, «Well, that’s stupid.» It’s no longer a fixed puzzle – randomizing it each time could make it unwinnable. So they’ve gone one step further, not only using random layouts within a theme, but changing the randomization every single time you replay a level.

JF: That was part of what I was thinking about. Did you ever consider the idea of presenting the player with random caves that were different each time?

PL: It never even entered my mind. But when I saw Candy Crush, I thought, well, maybe I should have done that. At first, I rejected the idea, but actually, I’m a fan of Candy Crush. People are surprised to hear that. They think, «Oh, it’s just a match-three game, what’s the big deal?» But I was really quite converted.

I think you’re saying the same thing: I could have randomized it so that every time you played a cave, it was slightly different, right? I could have done that. But I had this mindset that no – this is a puzzle, and I know it’s solvable. If I had randomized it, there’d be no guarantee it was solvable anymore. So, I had a different approach.

And I don’t have any regrets about the way it turned out. I’m not even sure there would have been a way to randomize it every time back then. But no, it never crossed my mind.

The mindset at the time was very much: you have a time limit to run through a level, and the level is always the same. All the platformers back then, for instance, people played them by muscle memory. So, it was just a different way of thinking. I’d like to think I innovated on a few things, but not everything.

An instant success

JF: Why do you think Boulder Dash became such a hit?

PL: Well… for one thing, it didn’t surprise me. I think any artist, whether they’re making music, visual art or a game, really has to love what they’re doing. They have to satisfy themselves first. That probably gives them a lot of confidence, and with that, the belief that the rest of the world will love it too.

So that was the number one thing: I always believed it would be popular. That said, I could have been completely wrong – this happens all the time.

Why was it popular? I think it appealed to a wider audience. For example, I think women were just as likely to play the game as men. You can make all sorts of arguments about that. It might be too simplistic to say, Well, women don’t like shooting guns and men do, and therefore first-person shooters tend to attract men. But I got the sense that Boulder Dash appealed to both sexes and all ages.

There were some nice psychological elements too, like the feeling of being both the hunter and the hunted. There’s violence in the game, but it’s more like being blown up or crushed by rocks. And there’s also the puzzle-solving aspect. The graphics, pacing, and sound effects – I think they were all great.

But in the end… who knows? There’s a famous quote from a screenwriter that basically says, «nobody knows». You do your best, put it out there, and you’re either lucky or you’re not. For all I know, First Star Software could have done a terrible job at publishing or advertising. But I was lucky, and they did reasonably well. They were fine. There were some nice people there who were helpful.

Sometimes they made requests about the game or the packaging that I didn’t like, and I refused. But I guess they were willing to give me a certain amount of artistic control, even though they were technically in charge. So yeah, they were good to work with for Boulder Dash.

RP: Did you get paid up front for the game, or was it a royalty deal?

PL: It was a publishing agreement. So typically that involves an advance, and then royalties based on sales and licensing, things like that. That’s how I was paid.

As for the rights, they stayed with them. The right to the Boulder Dash name stayed with them.

RP: Was that something you regretted later on?

PL: Not really. I’m not one for business. I consider myself more of a scientist or an artist – somewhere in that creative space. I’m a creative, you know, what they call a creative person in the industry. And on the other side, you have the suits. The ones who hire, the accountants, the ones who put the whole thing together. They handle the logistics of publishing, the physical production, the money collection, the financing.

Creators and business people tend to be on opposite sides. Doesn’t matter if it’s video games or music, it’s always like that. Hopefully, they get along and don’t destroy each other, but often they don’t have a lot of respect for what the other does. Still, in the end, you really need both types for something like this to succeed.

JF: Were you involved in any of the later games?

PL: Pretty much right after First Star published the first one, and it got the response that it did, they commissioned a second game. So there was Boulder Dash 2, which was basically Boulder Dash 1 with a new set of caves.

Back in those days, if a game had something like ten levels, it was considered complete. Unlike modern games, where you might have hundreds or even unlimited levels. So it was mostly about creating a new theme song, adding another 16 caves, maybe introducing a character or two. That came together fairly quickly.

When number three came out, I think First Star had decided the economics worked better if they had control of the creative side as well. So I believe they handled that one internally, although I’m not entirely sure. I can never quite remember the full story behind Boulder Dash 3. Not many people know much about it, and I can’t really tell you much either.

Then Boulder Dash 4 was the construction set. That was their idea too, but it had a lot of technical issues, and they asked me to fix them – which I did, as a courtesy.

RP: Did you have anything to do with the arcade version of Boulder Dash?

[Editor’s note: We’re referring to the Exidy version here, not Data East’s later versions]

PL: No, that was just something that was presented to me. Occasionally, they’d keep me updated on what they were doing, they’d send me samples and bits and pieces like that. But no, I didn’t have any involvement.

I don’t think anyone really “created” that version in a traditional sense. Someone just had the idea to stick an Atari computer inside an arcade cabinet. I think that’s essentially what it was. They just put Atari hardware, not necessarily the full computer, but the core hardware, inside a cabinet, hooked it up to some kind of mechanism for taking quarters, and built it out like a typical arcade machine.

From what I remember, the cabinet was designed so it could easily swap games in and out.

RP: Did you ever try the arcade version?

PL: No, I never did. I don’t think I was even interested enough to go looking for it. I had no idea if it was even available in Toronto. And by that time, I was a little too old to be hanging around arcades anyway. I just wasn’t interested anymore. I was in a different phase of my career by then.

After Boulder Dash

JF: Why did you leave the games industry?

PL: That’s a good question. I’m not sure I can give you a single clear answer, but I can offer a few pieces of one. For starters, being a solo game developer is pretty lonely. I’ve always preferred working in a community, collaborating with people.

Even though I managed to make Boulder Dash pretty much on my own, fueled by a lot of luck, the process was still very internal. One of the best things about making Boulder Dash was that I could pour so much of myself into it. I know that’s a phrase people use, but in this case, it’s really true. It was incredibly gratifying to bring together the technologist and scientist in me with the artist, animator, and musician. That was what more or less fueled me through the development of Boulder Dash.

But somehow, I didn’t see that being sustainable in the long run.

Also, the industry itself was changing—going through ups and downs. There was the famous [American] 1983 crash in video games, which made everything feel a bit unstable. Economically, things looked like they might fall apart.

And then the hardware was changing. I really loved the Atari. It was a wonderful machine for creative games. But things were shifting to platforms like the Commodore, which was almost as good, and then to machines like the PCjr. IBM wanted to get into the home gaming market, but I didn’t like the direction that was taking.

I had lots of notebooks full of game ideas, but who knew where any of that would go? Boulder Dash was a bit of lightning in a bottle. Most of the core ideas came to me in the first two or three days, and everything else followed from there. I could have chased other concepts, but maybe they would have led nowhere.

In the end, 3D computer graphics became a very appealing area to be in. It took a few years, but I eventually joined a company doing that kind of work. It felt more right for me. I got colleagues that I worked side by side with, and it was just a more steady and predictable kind of environment. The games industry can be very hit-or-miss. I was lucky to have a big success with my first game. But what if the next one didn’t go anywhere?

So like I said, there were a lot of factors. I can only answer that question in fragments.

JF: What did you do after leaving the games industry?

PL: As mentioned, 3D graphics was an appealing area to be in. I’ve always been interested in creating interesting images and animations that are based on mathematics and science. So I was very much drawn to a company called ALIAS Research, which was based in Toronto. It was a startup, and they were writing software programs on Unix machines that could be used by movie studios creating special effects.

So I joined them in 1994, about ten years after Boulder Dash. In between, I’d done a lot of freelancing and working in various graphics related projects in Toronto. But this was more or less my dream job. It was hard to get in there, usually you needed a higher degree in computer graphics, which I didn’t have. But I got lucky and met a few people, and got in.

The first product I worked on was a 3D paint package called Studio Paint [later renamed Autodesk Sketchbook], which was being built for car companies so they could use it when designing new cars. That eventually evolved into a 3d paint program where you could take 3D assets and paint on those.

I worked then on a variety of projects in computer graphics, like Maya which is still being used today. I was always on the software side and specialized in geometry-related algorithms. Texture mapping, that kind of thing. I wrote a few papers and filed about nine patents. It was very technical work, but also really rewarding. And the team was great. Lots of smart people, both developers and artists. It was a good mix of creative and technical folks.

Eventually, though, the company started changing. It got acquired, and then it acquired others, and eventually it became part of Autodesk. That company had more of an engineering-drawing DNA, and the culture shifted. It just wasn’t the same anymore, and that was the end of the road for me, after about 15 years.

Then I transitioned into web-based development, often with a visual component. Things like 3D architectural visualization. That was my last professional chapter before retiring.

JF: So you’re retired now?

PL: I am. Happily retired.

JF: Do you still play games?

PL: Not a lot, really. Now and then. But definitely not like the stereotype of young men today who spend all their free time glued to their consoles. I might buy a game once every five years, play it for a few weeks, just to see where the industry has gone. And I’d usually think, «Wow, this is really good.»

One that really stood out to me was Portal. That was a big hallmark, and I really liked it. In fact, Portal 2 is probably one of the only games I’ve played all the way through to the end. I can’t really remember much else beyond that. I also have to admit, that I’m a big fan of Candy Crush. I’ve been playing it for years and still do.

I know that means I’ve probably missed out on a lot of great stuff over the years. I’ve sampled good stuff too, but it’s just not a primary thing for me anymore.

JF: But I see from your website that you’re still doing computer stuff?

PL: Yes, though a bit less than I used to. For a while, I was doing a lot of small programming projects. Little math demos. They may not look like math demos, but usually there was some mathematical idea behind the imagery.

I haven’t done that in a while, so I wouldn’t say I actively program anymore. If I got inspired, maybe. These days, I spend more time at the gym, lifting weights. They say resistance training is good as you get older. And I spend a lot of time at the rock climbing gym. I like the connection between Boulder Dash and rock climbing, both have been recurring themes in my life.

I’ve also been working on what I call the “digital archaeology” of Boulder Dash. Thankfully, the original floppy disks were archived just in time, as they were already starting to deteriorate. The images aren’t perfect, but they’re good enough. They’re like ancient ruins: a little broken, but still recognizable. I’d like to do more work on recovering the different stages of the game’s development.

And maybe this is something that happens when you get older, but I find myself thinking more about the past than the future. Not my personal past or future, but more generally. I used to be very focused on what was new and cutting-edge. Now I’m really drawn to things like 19th-century mathematics books, especially old geometry texts, and history in general.

And yeah, these days I spend a surprising amount of time talking about Boulder Dash, doing interviews like this, or working on getting my materials into a museum for preservation. That’s a slow, time-consuming process, but it’s rewarding. Strangely enough, 40 years later, Boulder Dash still takes up a good chunk of my time. And I enjoy it.

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Note: This interview was conducted online, and we’ve used AI to help us transcribe and clean it up. That was followed by a manual process of checking for errors and improving the text. The full interview text has been approved by Peter Liepa, who helpfully offered a number of corrections and improvements on his own.

We’d like to thank Peter Liepa for taking the time to talk with us, and for all his help with this article.

Next week, we are going to follow up with an interview with Stephan Berendsen from BBG Entertainment, about their new Boulder Dash game.

• You can find more articles in English here