Illustration by John Watson

The man who turned nuclear war into a videogame

Ivan Stepanov on how Nuclear War Simulator explores the potential fallout from atomic conflict
September 6, 2023

Ivan Stepanov grew up about 150km from the main Soviet nuclear testing area. His home was the city formerly known as Semipalatinsk, in Kazakhstan. And while the bombs being tested weren’t the largest in the USSR’s terrible arsenal, they were still big enough to send shockwaves coursing through Stepanov’s life. “The topic,” he tells me, “was widespread in the city. There were stories of soldiers working on the site, of people nearby who had to face the consequences.” The young Stepanov used to cut out newspaper stories relating to the fallout, whenever they appeared.

This archive of atrocity would be all too relevant to the project that, decades later, Stepanov embarked upon—and which, earlier this year, reached its fruition. Almost single-handedly, and alongside a full-time job working on self-driving cars in Germany, he has made a videogame that describes what would happen in the event of atomic conflict. It’s called Nuclear War Simulator. And it’s available on the same gaming platforms where you can also bounce around as Lara Croft or vaporise aliens as Halo’s Master Chief. 

Except calling NWS a “game” is something of a misnomer—even if Stepanov does so himself during our conversation over video. “I don’t want to create the expectation that it is a game,” he says. “Because there are no goals in it.”

And he’s right. There is no winning; there is no losing in the traditional sense; there is only merciless simulation. As the player—or spectator?—you establish a scenario, such as an attack by the US on Russian missile silos, and simply watch it unfold. The utilitarian graphics—triangles and squares moving across a map of the world—belie the roiling horror they signify: fire, radiation and megadeaths.

“I realised that there is no computer game”—that word again—“that deals with this subject seriously,” says Stepanov when I ask him… why? NWS, by contrast, is pointedly serious. Once its simulated conflicts are over, you can pass your mouse over the scarred globe to discover what, precisely, has happened. Death counts. Fallout patterns. Radiation sickness timelines. All based on the best data and modelling that the designer had to hand. “There is,” promises Stepanov, “a very detailed wind database, with multiple layers of spatial and temporal resolution.”

I don’t want to create the expectation that it is a game

Is NWS morbid? Perhaps, though not just for morbidity’s sake. Stepanov insists that, despite all the number-crunching, he is trying to communicate the horror of nuclear war by making it personal. “It’s to answer different questions. The first one is: what would happen to the world? Then: what would happen to a country? And finally: what would happen to you and your family?” To that end, you can drop little digital people onto NWS’s maps to discover how they would fare.

Besides, Stepanov’s program is already being used for academic research. “There’s one project at Princeton,” he explains, “where we’re trying to answer the question of how changing the composition of US personnel would affect deterrence.” There are, apparently, at least a couple more research projects in the offing.

But what about the effect of nuclear war—or, more specifically, of Nuclear War Simulator—on Stepanov himself, the kid who grew up in the vicinity of a test site and never fully left it behind? “If you try to research this topic,” he concedes, “it is very depressing. There’s quite a lot of literature on the effect of firebombing in the Second World War. It is very graphic and goes into detail about people dying on a massive scale.”

“But, at some point, your day-to-day problem is fixing bugs in the game. Writing code. And then… then it gets more abstract.”