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Nuclear War Simulator

A nuclear conflict simulation and visualisation tool · By Ivan Stepanov

First release - bugs and suggestions

A topic by Ivan Stepanov created Jun 28, 2020 Views: 1,834 Replies: 60
Viewing posts 1 to 29

This is the first release of the simulation.  Lets discuss bugs and things you want to see added to it.


Anti-Ballistic Missile systems (THAAD, S-500, whatever) would be neat.


I will probably add ABM one day but it is rather difficult to model realistically and in reality it is so unreliable that it will have very little influence on the results.


What could be the possibility to implement "automatic" interception animations that deteriorate the cluster at whatever respective phase of the ICBM launch cluster consists of, by look up tables for ABM exercise data?  That way it would (at least) operate on the statistically realistic side of things and perhaps be faster to implement?


It should be relatively easy to build some kind of statistical ABM, but I am not sure how realistic it will be. There are so many factors that are influencing the interception rate, which will be very small in the end.


  • U.S Faction
    • Minuteman III speed (terminal speed 7826.66667 m/s), accuracy/ circular error probable (240 m), mirv radius, apogee (11,000,000 m) and range (greater than 9,700 km) may not be correct. Can also carry up to 3 warheads and only can carry W87-0 or W78. Though New Start limits to one warhead
    • Trident II speed(terminal speed 8,060 m/s), mirv radius, and range (more than 12,000 km reduced load or about 7,600km Full load) may not be correct. Also can house up to 14 w76-1 or w76-2 or 8 w88. Due to New START in practice each missile carries 4 warheads
    • AGM-86B range( greater than 2,400 km or 2,400,000 m) may not be correct. Can only carry one W80-1
    • Nuclear weapons yields are correct.
    • Ohio Class subs can spend a lot longer than 30 days off base/only limited by food speed (37 km/h) way off. Also can carry 24 SLBM but limited to 20 due to NEW START
    • B-2A speed (cruise speed 900km/h), range (11,000km), and altitude (ceiling 15,200 m) may not be correct. Can carry 16 B61 or 16 B83
    • B-52H speed (844 km/h), range (14,080 km), and altitude (ceiling 15,200 m) may not be correct. Can carry 12 AGM-86
    • F-35 speed (max 1,296 km/h), range (2,800 km), and altitude (ceiling 15,200m) may not be correct. Only one B61-12 
    •  F-16 speed (1,482 km/h), range (4217 km), and altitude (ceiling 15,200m) may not be correct. Both B61 and b83 2 only for both
    • Tornado speed (1,482 km/h), range (3,890 km), and altitude(ceiling 15,200 m) may not be correct. Can carry 4 B61’s


  • Things I would love to see added/ Explained
    • Other Factions fully implemented, China, North Korea, Iran, ECT
    • Where can we get the KML files to populate with real bases/everything?
    • Also, I cannot get aircraft's gravity bombs to work properly can you make a video how those specifically work?
    • Where do you get the information for this simulator both nuclear and military craft?
    • Have the ability to, since this is a simulator, see the past effects of nuclear accidents and detonations.
    • Conventional Naval vessels
    • Have in the future ABMS, and be able to the what the effect of countering both bombers and submarines would have using convention weapons systems.
    • Possibly be able to tune this simulator into a DEFCON similar game.

Also, if you would like assistance on getting values for military equipment I am willing to help. Like yield, range, speed, mass, ect.


Oh wow, thank you for the detailed review and suggestions!

Many values are definitely incorrect. My main concern were the humanitarian effects. If you want to create a realistic database yourself, the ideal way to do it is: create the database, pack it into a zip folder and upload it onto the mods website:

This way, everybody else will be able to easily use your database.

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About the KML files where do we find those I saw in the youtube file explaining it you had some so. Also gravity bombs I cannot seem to get to work are they fully implemented yet? If implemented could you do a short youtube video showing how to use them?  I am also willing to assist on this project if you would like sir, I have some Unity experience and am currently enrolled for networking and cyber security in the USA.


For the KML files you can start here:

Or just google for specific object type and KMZ.

And here is the video on how to use them

It would be difficult to assist me with the simulation directly. I think realistic datasets and scenarios are what the simulation lacks most right now. Later, I hope to introduce script modding so you can go wild there.

Could you make a road map or list of what you plan to add to this simulator?


I probably should make a trello board with the roadmap.

Would greatly appreciate that. I am going to be sending you an email about this so please do not delete it, it will be from a gmail address.


Great. Thanks!

could uadd a link or Utorrent link i keep downloading and it keeps failing i really wanna play it :}

i suggest you add something like making a custom missle where you can design the shape of it and the shape of it affects the damage it does or the accuracy of it


Making the missile design process a little bit more interactive is a great idea. However, the shape of the missile usually has little effect on the characteristics like accuracy or yield.


This is really great...I've found a bunch of performance bugs and also rendering bugs through running it, however.  I'm an experienced unity developer and performance engineer for there any way you could consider releasing the code for this on github so you can accept patches and changes directly?  Even if you don't do so under a truly open source/permissive license, I'd still submit performance enhancements and bug improvements.


Thanks! You are right, there is a lot of optimization to be done. One issue I am struggling with is the performance drop when rendering a lot of lights on weak hardware. I will probably make so of the code open source (like the effect codes), but not the entire project. Please let me know where you find most significant performance issues and I will try to fix it.

Hello, I have downloaded this game  and followed the instructions, however when I launch the exe file or the application file labeled Nuclear War Simulator with the Unity symbol as the icon, nothing happens the application is able to be seen and ended through task manager which says it is running but nothing comes up and the appliaction is shown only using memory and nothing else and nothing ever pops up on screen and the game never actually opens and starts, I was wondering if you could provide any support on this issue, as maybe you have seen it before and know the cause, thank you for your attention.

Hello, I have downloaded this game  and followed the instructions, however when I launch the exe file or the application file labeled Nuclear War Simulator with the Unity symbol as the icon, nothing happens the application is able to be seen and ended through task manager which says it is running but nothing comes up and the appliaction is shown only using memory and nothing else and nothing ever pops up on screen and the game never actually opens and starts, I was wondering if you could provide any support on this issue, as maybe you have seen it before and know the cause, thank you for your attention.


Hi Josh, I am very sorry to hear that it doesn't work at all for you. Can you send me your hardware stats and your Player.log file from C:\Users\<your user name>\AppData\LocalLow\Ivan Stepanov\Nuclear War Simulator to my email

Also you can try to start the simulation by right-clicking on the exe-file and select "Run with graphics processor -> High-performance ..."

Where is this option under right-click? I have the normal options and the only one close to what you were saying is the Run As Administrator option which also does not work.


Do you have Windows 7? If so you can try to select the defauld graphics card in your NVIDIA Control Panel. What is the model of your graphics card?

i have gt 630 isit enough


I'm not sure. GT 630 may be too old. Just download it for free and let me know how it goes.

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i cant play it cause it keeps failing could u please upload it on its free i really want to play it you know if u upload it on mega pls reply the link

i downloaded it once, tried to extract it, f*cked it up because i closed my laptop, and had to redownload. the second time, the download failed because the browser crashed. the third time it worked perfectly, other than that it took way too f*cking long to extract. after all that, the first time i ran the game, it crashed while telling me about MIRV's. the second time, i was so confused  about what to do so i clicked the play button to see if any tooltip would tell me what to  do once the game started playing. but then there were just missiles flying all over Europe. then i realized they were flying all over the world. Who's at war with who? how can i tell? i found a button next to the play button that let me make a bunch of nuclear explosions so i just started clicking on cities in russia. after a while i guess i was trying to figure out how to place a base i saw a button that said something like "calculate casualties" a few seconds after i clicked it, the game crashed.

TLDR: I f*cked up the zip extraction, then the download failed, then the extraction took forever, then the game crashed, then missiles went flying, then i made explosions all over russia, then i tried to calculate the casualties, then the game crashed.


Hi Tommy, wow thats a lot of problems in one place.

Long exraction time is a known issue. The reason is a larg number of map files. I have to solve it one day.

It is weird that it crashes when you press calculate casualties. Can you tell me your system specs and send me your Player.log file from C:\Users\<your user name>\AppData\LocalLow\Ivan Stepanov\Nuclear War Simulator to my email after a crash?

Could you create a change log that says what has changed between versions before downloading?


Yeah, I should do it. You are right. Thanks!

Could you try for an upload to steam? that would be great

Hi Ivan, I really appreciate your work.
May I suggest to implement Aircraft Carriers and Air to Air Refueling? This will really improve the simulator since all fighters lack the range to  accomplish long range missions.


Thanks! I'm glad to see that you like it.

I will have to add aircraft carriers at some point, but I am not planing to add refueling. Refueling would introduce too much complexity into the simulation. You can account for refueling by simply including it into the range of the aircraft.

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How's that Linux port going? I am currently running this on a embarrassingly weak laptop, so I was also wondering how to change the graphics settings.




Little progress on the Linux port ... :(

You can find graphics settings on the left side of the screen, but the only setting that will help you with performance is the number of explosions with lighting animation. What is your hardware? Are you having serious issues with performance?

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Hey no problem, I'm on the verge of a hardware solution that will let me run "Windows" under Linux. The laptop I'm running this on is a Latitude 3180, so it's pretty weak. But I'll paste specs here:

             Machine name: private
               Machine Id: private
         Operating System: Windows 10 Enterprise 64-bit (10.0, Build 18363) (18362.19h1_release.190318-1202)
                 Language: English (Regional Setting: English)
      System Manufacturer: Dell Inc.
             System Model: Latitude 3180
                     BIOS: 1.10.0 (type: UEFI)
                Processor: Intel(R) Pentium(R) CPU N4200 @ 1.10GHz (4 CPUs), ~1.1GHz
                   Memory: 4096MB RAM
      Available OS Memory: 3924MB RAM
                Page File: 4109MB used, 1412MB available
              Windows Dir: C:\Windows
          DirectX Version: DirectX 12
      DX Setup Parameters: Not found
         User DPI Setting: 96 DPI (100 percent)
       System DPI Setting: 96 DPI (100 percent)
          DWM DPI Scaling: Disabled
                 Miracast: Available, with HDCP
Microsoft Graphics Hybrid: Not Supported
 DirectX Database Version: Unknown
           DxDiag Version: 10.00.18362.0387 64bit Unicode
           Card name: Intel(R) HD Graphics 505
        Manufacturer: Intel Corporation
           Chip type: Intel(R) HD Graphics Family

In other words it's a potato. Anyways, maybe making draw distance for details or more detailed lighting settings?



im having a bug where i click the application and its just staying on the openiing screen


Thank you for letting me know! Can you give some more details on when it is happening?

You could send me the Player.log file from the folder C:\Users\<User name>\AppData\LocalLow\Ivan Stepanov\Nuclear War Simulator after a crash. My email:


Try to run it as Administrator. It may fix it.

ok thanks for feedbak.

How do you edit an attack plan once you've created it? It doesn't seem very intuitive.

Also, how do you reset an open scenario to remove all the explosions?


I have to admit, there is no way to do those things, but I just wrote them down into my TODO list. Thanks!

I have some suggestions for additional KML support:
1. A way to add locations en-masse. I found I very much wanted this when working on soviet missile fields, some of which have almost a hundred silos. That's 200 clicks, assuming I don't mess up, for just one field! If we could add an entire folder to the Locations to place that would save me a lot of trouble.

2. A way to remove locations from the active locations. Oops, I clicked on a silo #99 too many times and it's in the list twice, now I have to go back to the beginning. This would also be a time saver.

When I'm done I'll upload a scenario representing the situation in November 1983.

While I'm at it, some pie-in-the-sky suggestions are to be able to mod population density (for example, to go back in time) and countries (also to go back in time to include the USSR, DDR, BRD, etc).

This is an excellent tool, I am amazed already at what you've done.


Thank you! I am aware of the issues

1) I will probably not make an option to add whole folders because a folder can contain mixed types of objects. Instead I will probably add an option to use Shift to select a large number of objects (like when you select files in Windows)

2)Yes, I know its a problem. I will add an option to remove the last element.

(3) modifying population density is difficult to do in an accurate way. I could add a country-wide modifier, but it is probably too coarse.

Thanks for the compliment and thanks for complaining! It helps A LOT!


Just implemented points 1 and 2. Wait for the next update ;)

I'm excited!  I have two more suggestions/questions:
4. Early warning/RADAR detection and integration into plan execution. With this you could simulate Launch Under Attack and explore the influence of asset basing and RADAR sites on strategic stability.

5. Bomber interception. Related to 4, and I know you've been asked about ABMs in the past, but fighters and SAMs are a lot more plentiful and capable of intercepting bomber missions compared to anti-ballistic missiles. This would allow you to look at standoff capabilities in more detail, for example.

It goes without saying that NWS is everything a nuclear war wonk could ask for, and more. 

I did notice a few things, only one of them is worth bringing up here as of yet. The pop density maps (when you overkill an 'entire' country) seem to add up to a population larger than the "static" population denominator (which I gather was borrowed from one of the world factbooks). I'm wondering if it'd be advisable to use the "density sums" as the baseline instead, so our fatality percentages don't get thrown off. 


Thank you very much for the compliment! I really appreciate it. There is still so much to do, we are far from done.

Your observation is correct There is a discrepancy between the given total numbers and the total numbers when counted from the population density. I already have it in my TODO list and will hopefully fix it soon.

Let me know if there is anything else to be improved!

Does there have to be an internet connection to calculate casualties/fallout? I feel as if there might be a bug with internet connection if there is one required. This might also explain why the mod page won't load in

Nevermind. I have fixed the problem. My antivirus is very sensitive, and blocked the game from accessing TempFiles


Can we have a 'time since launch' visible on the screen i.e. since the first missile were fired? Also the ability to see time to impact of a selected warhead.

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So first of all, bugs. For the most part things work fine. The game starts, missiles fly, civilization as we know it ends. The one issue I had was that casualty calculation doesn't work for me in the main exe, which is a tad unfortunate since the main exe is the most stable for me. The problem is solved if I use the OpenGl.bat, but opening the game that way seems to have some stability issues, in particular the game tends to crash if I run it in real time (I enjoy running it in real time rather than with any time compression since I can pretend I am experiencing an actual nuclear war and get a sense for how long that feels). I am running Windows 10 with DirectX 12.

On to suggestions. I don't want to suggest too much in terms of features, having learned a bit about game development and in particular the dangers of feature creep. But the thing that seems most urgent to me (after bug fixes and stability improvement) would be the addition of a Cold War scenario. I've seen what happens to the world in a modern nuclear war now, but what about back when nuclear stockpiles were at their height? This would mean a new map, with redrawn borders (divide East and West Germany, unite the Soviet Union) and population densities set to sometime in the Cold War (I'm thinking perhaps around 1985 when Soviet stockpiles peaked? Or 1965 when American stockpiles peaked? (according to Wikipedia, which may be a bit course, going in five year increments)), and of course everyone would have their 1985/65/?? nuclear arsenals. Does this sound feasible? I can understand if it isn't, since re-adjusting population levels to several decades earlier would probably be a lot of work.


Thanks for the detailed description. I'm glad that most of it is working and civilization ends properly. Can you tell me what GPU you have? The main exe should work on most modern GPUs.

I was actually hoping that someone will use it in real time. Good to know you are indeed doing it. I will try to reproduce the error when running in real-time.

There are a lot of people asking for a cold war scenario. I will probably never have the time to do it myself, as I spend most of the time coding, but you can do it using the editor. Make appropriate blueprints, put them on the map and generate attack plans. Maybe someone else will create such a scenario and upload to the server. Population density is indeed difficult if not impossible to adjust. What i will probably do in the future is introduce a country-wide adjustment of population. It will under or over represent some cites but it is probably the best I can do.

Let me know if there is anything else you want to see in the simulation!

Ivan, if it might help with the task of population density, NASA SEDAC has some population estimates from 1970, 1980, 1990, and 2000 on a 30 arcsecond resolution.  I don't know if those are easy to use in your format, but some structured data does exist, even if it's an estimate. Easier than doing it yourself! :)


Thanks for the data suggestions. I was indeed using this exact data last year. However, there is a problem with it. They are not detailed enough. Due to the way, the maps are produced, population density is averaged over city areas. Overall the population count is exact, but the density spikes are missing. Some fire models are using population density as input, so the NASA SEDAC data produces wrong results. I will try to find another dataset.

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My GPU is: AMD Radeon RX 5700 XT

A country wide population adjustment sounds acceptable to me. It won't be fully realistic, but it ought to get good enough results for large scale attacks even if things are off in individual cities. 

My suggestion would that the first release of a population adjustment feature be the simplest possible version of such a feature (every pixel of population (do you have a name for your most discreet units of population?) gets a simple increase or decrease that is directly proportional to the country wide increase or decrease). But write it so it is easy to change later. Then, if you come across information on any historical trends for how rapidly denser population centers tend to grow vs sparser population centers then you can rework the feature so that the proportion of the population change that is reflected in each square of population is directly related to how populated that square already is (it is probably on some sort of S curve, with denser population centers increasing more rapidly than sparser ones up to a point and then leveling off). This still won't be 100% accurate, but ought to significantly reduce the error for individual towns and cities, and further increase the accuracy of large scale attacks.

Edit: Alternatively, is the resource that HerrTom provided compatible with whatever you used to generate the population map in the first place? How did you create that anyway? I assume it had to be automated in some way (feed the right data into the right program). I simply cannot imagine any human having the patience or lifespan to manually input the correct number for every discreet unit of population that you had. And mad props to you or whoever on your team worked on it if it really was done manually (actually, props no matter how they did it, that is an outstanding population map).


Hmmm strange. A 5700 XT is new enough to support NWS. Maybe something with the drivers or the DirectX11 version.

On the population density, I will probably go with some country-wide scaling factors for a number of years. Later maybe see how individual population centers behave or find complete population density maps for the cold war years.

Here you can find the current population density map:

I think they have maps dating back to 1975.

I had to write a script to convert the data from their format to the NWS format. It would be a total nightmare, to do it by hand :D (maybe it should be adopted as a form of punishment for criminals...)

So when's the next build coming out?


It is coming. I just can't tell when yet.

okie dokie