Fifteen years ago to the day, with some variance depending on where in the world you lived at the time, Thief: The Dark Project, went on sale. It is one of the games that continues to define the possibilities of first-person architecture and also an example of interactive storytelling that has endured over a decade and a half without being fully tapped. Some of the lessons that the team at Looking Glass laid out in their masterpiece has influenced a great deal of gaming. Other parts, like the Thief himself, appear to have gone unnoticed. Here, we remember and celebrate the brilliance of The Dark Project.

We all have memories of Thief. Some are more recent than others.

Kieron has written extensively about Thief in the past and recognised, in the days before he had properly invented games journalism, that it was quite important.

It seems miraculous to me now. It’s like if Lester Bangs’ first assignment was to go and interview the Velvet Underground. Within the first week on the job, I’d found my Lou Reed…Thief, in a real way, justified my entire approach to the medium. So, if you’re ever looking for something to blame, blame it.

Read this.

Alec, on the other hand, played The Dark Project for the first time last week. You may have witnessed his efforts.

And now, the rest.

John: Thief changed how I see the world. Not in a significant, life-changing way. Just after I’d played it, for a bit, I was unable to go anywhere, look at anything, without spotting the shadows, instinctively calculate routes that would avoid lights, and consider how I was going to get from the top of one nearby building to the next.

Its astonishing atmosphere was invasive, leaking out from the game and into reality, leaving me sticking to walls and momentarily panicking at the sight of oncoming car lights, before realising myself. I couldn’t walk past the university buildings where I was studying without planning climbable routes up to their roofs. And then fighting the temptation to try.

The photophobia the game was capable of inducing is testament to the intensity and thrill that occupied its every moment. The infamously terrible graphics were never a problem, and they were never truly terrible. They were atmosphere, an extra layer of grittiness in this dark, creepy world, amongst whose dark you crept about.

I could, and probably should, go on about the ludicrous thrill of evading capture, successfully sneaking past guards, a perfectly aimed water arrow, and the joy of clearing a level unseen. But what I most want to champion about Thief was the extraordinarily subversive nature of its difficulty levels.

The higher you made the difficulty, the fewer people you were allowed to kill, or even stun. It was, and still is, such a contrary approach to gaming, and a bold statement of how exquisite game design affords a game far more freedom to be interesting. If your game is good enough, you do not need to bury it beneath increasing numbers of enemies, but rather expose it even further.

Thief looked dated when it came out in 1998, but weirdly looks less so now. You can absolutely go back to it, and still become utterly engrossed in its world, and be completely terrified by its sneaky brilliance. It’s simply one of the greatest games ever made.

Jim: There are few games which are also revelations. Thief was one of these, for more reasons than mere radical game design. On a personal level its existence is inextricably tied up with my life’s direction as a whole. The events of 1998, and by events I mostly mean games, pretty much confirmed that I would end up working with games in some capacity. Specifically, it determined that I would spiral towards games journalism like a tiny spaceship full of childhood hope caught on the event horizon of a career black hole.

Hopefully Kieron won’t be reading this article, so it’ll be safe to say that his Thief review – read because I’d started buying PC Gamer again that year – reminded me how entertaining and affecting I found games writing to be. Amiga Power, the magazine I had once read religiously during its short life, had laid the foundations for this appreciation, but it was by reading the Thief review in PC Gamer that I was confirmed as a subscriber, and that ultimately led me to end up working for that same magazine an couple of years later. I didn’t even know I wanted to be a games journalist when I read that review – it didn’t even enter my mind as a possibility – but I knew I had to get the game, and that I knew that it would matter.

It did. It was thrilling. It was appallingly scary. It made me realise that vulnerability is more important to me in games than empowerment. It made me love shadows, and it made me love first-person movement. I’d been in love with the first-person perspective in games since I first touched a keyboard connected to Wolfenstein, but I don’t believe I’d really thought about movement and embodiment until I’d started playing Thief. The levels weren’t simply blockades to blasting, they were situations to be unravelled. The freedom the game insisted you take responsibility for was intoxicating, and it diminished all its first-person peers.

As I said, it was revelatory.

Browsing the Thief Wikipedia page, and looking down the credits, I realise it’s impossible to truly define how significant Thief was so many people of far greater importance than myself. It launched careers, and it defined design approaches for the decade that followed. Thief represents a waypoint, and a signpost to greater things. Few games manage such a legacy. Fascinating that so many of them should have appeared in that particular year.

Adam: When I played the demo, I realised that I was experiencing something new. It was on a cover disk – it must have been because that’s where such things lived 15 years ago – and I don’t remember thinking it was important until I installed it. I don’t remember a fanfare. There’s no other game that caught my eye, so effectively, with a cutscene.

Thief’s mission prologues and story scenes are perfectly representative of the game that they punctuate. The art style is unusual, an apparent collage of mysteries, and the world is strange, a medieval cyberpunk directed by a knowing eye. They introduce a world full of threat and wonder, a fantastic creation that ejects goblins and saves its dark corners for crooks and cults. Across gaming’s greatest trilogy, Thief created a world like nothing else and told a story that was both personal and quietly apocalyptic.

Always quietly. Because as well as telling that story, Thief invented the stealth game as I understand it. Not the first, but the most meaningful for me and, I believe, for many people who grew up with a PC humming in the corner of their hhouse. It’s a game about the construction and manipulation of architecture, about the freedom to traverse a space while under threat. It’s a game about the boldness that leads to fear and the absolute terror of the unknown. Fear of the dark and the lust for shadows combine into an experience that is both empowering and horrifying.

It is the most significant game I’ve ever played, just ahead of Ultima VII. Both are games that made me love the possibilities of this medium, of the immersion, confusion and excitement that are possible when navigating strange spaces. At the time, Thief convinced me that the future was as bright as the shadows were dark and that everything from then on would stand on its shoulders. The Metal Age and Dishonored aside, those shoulders haven’t been tested, and I still believe it is one of the most important games ever made. Not the root that I believed it might become, but a seed to be studied and nurtured.

The term doesn’t always carry a great deal of meaning, but Thief was ahead of its time. The tech wasn’t ready, but did a damn good job, and the representation of people – in a fantasy environment – is something a lot of chainmail bikini and loincloth designers could learn from. Nothing since has made me love games quite as much but I wouldn’t love games half as much as I do if I’d never experienced it. Even though I tend toward strategy and simulation in my later days, in many ways, Thief is the reason I care so much and ask as many questions as I do.

And here is my love letter to the series.