This 'professional' end-of-the-world simulator is now available on Steam

At first glance, Nuclear War Simulator, which launched today on Steam, bears a real resemblance to DEFCON, the old (and excellent) Wargames-inspired strategy sim about turning the planet into a roasted chestnut. In reality, it's something quite different, and not really a game at all: It's "a detailed realistic simulation and visualization of large-scale nuclear conflicts with a focus on humanitarian consequences."

Nuclear War Simulator was developed by Ivan Stepanov and originally released in 2020 as a "professional tool" sandbox simulator capable of accurately modeling everything from real-life weaponry to defense systems, blast results, firestorms, fallout, civilian and military casualties, soot thrown into the atmosphere—well, you get the idea. And it's been used at pretty high levels. Princeton University’s Program on Science and Global Security, for instance, used Nuclear War Simulator to underpin its own research into nuclear war scenarios between the US and Russia.

Now it's available on Steam, with an impressive (although not what I'd call "fun") feature list:

  • Detailed effects of nuclear weapons, accurate reports on affects/results (including but not limited to radiation zones, casualties and fires)
  • Realistic delivery systems, up-to-date full known arsenal of main world powers.
  • Sandbox to design weapon systems and build conflict scenarios.
  • Individual civilians moving on the map and taking shelter.
  • 22+ predefined editable scenarios. 
  • In-game mod upload and download. (instant synchronisation)
  • Adjustable AI.
  • Integrated early warning and Missile Defence systems.

"This software should help you answer the question: what will happen if Russia and the United States or India and Pakistan use their arsenals?" the Steam page says, boldly ignoring the easy answer that those things would be very bad indeed. "You can design warheads, missiles and carriers, place them on the map, and execute attack plans to tell a credible story about how nuclear conflicts play out and what are the consequences. Using a high-resolution population density map and realistic weapon effects like blast, heat and radiation you can make an estimate of how many people will die in a conflict."

The first of a six-part series of brief documentary videos shared by Matrix Games uses the ongoing war in Ukraine to demonstrate Nuclear War Simulator's capabilities. It's clinical, yet surprisingly harrowing:

YouTube YouTube
Watch On

Speaking to PC Gamer, developer Stepanov said the Steam version of Nuclear War Simulator has been upgraded considerably from the original release, to make it both more detailed and more accessible.

"While this software is not a game in the classical sense (there are no predefined goals and no rewards) the user interface is intentionally very similar to a game and should be familiar to most people," Stepanov said. "The simulation now has a number of tutorials teaching basic functions and there are 30 premade scenarios coming with the simulation so that new users can jump in without any expert knowledge.

"If you want to create scenarios yourself, there is now a database of all currently deployed (unclassified) types of nuclear weapons and there are databases of where the weapons are stationed. With only a few clicks, users can place all US and Russian nuclear weapons at their real location. Then, an AI can be activated to run the scenarios with minimal input."

While the Steam release of Nuclear War Simulator has come a long way compared to the original standalone version, Stepanov has a number of ideas about how to continue developing it, ranging from improvements to graphics and UI to the addition of new nuclear strike effects and the expansion of civilian and military asset databases. He's also looking at improving the depiction of individual humans in the sim, "to make the simulation more personal." 

Steam Workshop support is also a possibility, although Nuclear War Simulator already has mod support through mod.io, where you can find add-ons like Cold War (Mid '50s), Taiwan Strait Hypothetical, Romanian Infrastructure Multi Plans, and various loading screens.

As for what prompted him to release it on Steam in the first place, Stepanov said Nuclear War Simulator is an "educational sandbox" similar to games like Kerbal Space Program or SpaceEngine. Both of those games have found sizable audiences on Steam, and he hopes NWS will be of interest to the general public too.

"Computer games are some of the most important sources of education today," Stepanov said. "One of the goals and one of the biggest challenges when making NWS was to make it not only realistic but also interactive and easy to use by non-experts.

"Nuclear weapons are the biggest threat to human civilization. By releasing NWS on Steam I hope that we can educate as many people as possible on this topic and together contribute to solving this problem and making our world safer."

Nuclear War Simulator is available now on Steam for $30/£24/€25.

(Image credit: Ivan Stepanov)

(Image credit: Ivan Stepanov)

(Image credit: Ivan Stepanov)

(Image credit: Ivan Stepanov)

(Image credit: Ivan Stepanov)
Andy Chalk
US News Lead

Andy has been gaming on PCs from the very beginning, starting as a youngster with text adventures and primitive action games on a cassette-based TRS80. From there he graduated to the glory days of Sierra Online adventures and Microprose sims, ran a local BBS, learned how to build PCs, and developed a longstanding love of RPGs, immersive sims, and shooters. He began writing videogame news in 2007 for The Escapist and somehow managed to avoid getting fired until 2014, when he joined the storied ranks of PC Gamer. He covers all aspects of the industry, from new game announcements and patch notes to legal disputes, Twitch beefs, esports, and Henry Cavill. Lots of Henry Cavill.

Read more
An enemy druid dodges a stab from the player.
As a Stalker sicko, the 2 hours I just spent with Atomfall have made it one of my most-anticipated games this year
A bird's eye view of a nuclear bomb detonating in Ara: History Untold.
Microsoft's Civilization 7 competitor escalates tensions with Firaxis' embattled 4X, announcing that nukes are coming with its impending diplomacy update
A person is abducted by a UFO.
A UFO true believer made a grand strategy space game with input from alien abductees, but now claims shadowy forces have shut it down with a bomb threat
A cybernetic woman holds a silenced pistol
I became a domestic terrorist to steal a lightbulb in the best immersive sim I've played this Steam Next Fest—and it isn't even a Next Fest demo
Atomfall Gamescom screenshots
Tread carefully, Atomfall's world includes 'exploding sheep' that can 'infect you with spores that creep into your lungs'
A massive beachhead assault in indie RTS Beyond All Reason
Over 110 players and 10,000 units clash as this free RTS celebrates its growing multiplayer scene with some of the biggest multiplayer battles ever fought
Latest in Sim
An ancient, angry stone mech from No Man's Sky's new Relics update
No Man’s Sky lets you unearth ancient, angry mechs in the astro-archaeology filled Relics update
Dwarf Fortress adventure mode art
After 23 years of making Dwarf Fortress, even its creator is still 'terrified' of drowning all his dwarves with aquifers: 'Part of the problem is we are just not good at videogames'
Tarn Adams, who cofounded Bay 12 Games with his brother Zach, talks about their single-player simulation game "Dwarf Fortress" during an interview at their home office in Poulsbo, Washington, west of Seattle, on December 9, 2022. - A cult favorite among indie game fans, "Dwarf Fortress" has been available for purchase on the Steam online store since December 6, a first for this title that has been distributed for free since its debut in 2006. The real-time management game, set in a medieval-fantasy world and involving overseeing a group of dwarves seeking to build a mighty fortress, has climbed to the fourth best-selling weekly title on Steam. (Photo by Jason Redmond / AFP) (Photo by JASON REDMOND/AFP via Getty Images)
Dwarf Fortress' creator is so tired of hearing about AI: 'Press a button and it writes a really sh*tty, wrong essay about something—and they still take your job'
Decorations in TCG Card Shop Simulator
TCG Card Shop Simulator finally adds the ability to decorate our stores, and suddenly all my profits are being spent on adorable Pigni posters
A person on a snowmobile riding a track in the forest in game Sledders.
Powder enthusiasts seem pretty pleased with new physics-based realistic snowmobile sim Sledders
Dean Hall at GDC 2025.
Outer space inspired DayZ's Dean Hall to become a modder and game developer, and now he's making a Kerbal successor called Kitten Space Agency
Latest in News
A screenshot from SaGa Frontier 2, showing one of the protagonists wandering through a quaint fantasy village
One of Square Enix' most underrated PlayStation-era JRPGs just shadow dropped on Steam
The titular character from Princess Mononoke is depicted riding the wolf goddess Moro and carrying a spear.
Studio Ghibli AI image trend floods social media, cheered on by OpenAI and denounced by critics as an insult to Hayao Miyazaki
Marvel Rivals tier list - Wolverine
Marvel Rivals director says a future patch will reduce the shooter's insatiable hunger for RAM: 'It's a very big problem'
Hogwarts Legacy potions professor holding a potion
An unannounced Hogwarts Legacy expansion and 'definitive edition' have reportedly been cancelled
Story of Seasons - A cahacter in a purple tuxedo stands outside in a town square talking to the player
Story of Seasons is doing another Harvest Moon remake and it might be the best the series has ever looked
Assassin's Creed Shadows change seasons - An upper-body shot of Yasuke looking cheerfully up into the distance.
Assassin's Creed Shadows puts up the 'second highest day-one sales revenue in Assassin's Creed franchise history'