Where every number comes from
This simulation estimates the order of magnitude of consequences - it does not predict a specific event. Every figure has a source. Here they all are, together with what those sources cannot do.
The most important thing, up front: all figures are indicative and not peer-reviewed. The physics coefficients come from public literature, but they still need to be calibrated and reviewed with a physicist. If you spot an error, write to us - we will fix it and credit you.
Blast physics
The radii of the fireball, overpressure zones (20, 5 and 1 psi) and thermal radiation scale with the yield by cube-root and power-law scaling - the standard treatment in the literature on nuclear weapons effects.
Glasstone & Dolan, "The Effects of Nuclear Weapons" (1977). The same scaling is used by NUKEMAP (Alex Wellerstein, nuclearsecrecy.com), the best-known public tool of this kind.
Casualty estimate
The estimate multiplies population density by the areas of the blast zones, with a different fatality share per zone (closer to the center - higher share). The number of warheads that hit the city raises the figure slightly, but it saturates: the first warhead already flattens the blast zones, so overlapping detonations add little. That is why a "shield" that intercepts a few warheads does not substantially change the outcome - two are enough.
A rough estimate based on the zones in Glasstone & Dolan. Not a substitute for a proper casualty study.
Population density
Currently a city-size estimate is used (from the town's population): village ~900, town ~1,600, city ~2,800, large city ~4,200, metropolis ~6,500 people/km². The same yield therefore kills differently in different places - but it remains an approximation.
Planned: GHSL (Global Human Settlement Layer, European Commission) - raster density at the exact location instead of a banded estimate.
Location, hospitals and schools
The city, and nearby hospitals and schools, come from OpenStreetMap (reverse geocoding via Nominatim, features via the Overpass API). The data depends on how complete OSM is for a given place - some places have a named hospital, some don't.
© OpenStreetMap contributors. Nominatim and the Overpass API.
Wind and radioactive fallout
The wind direction is real, in real time. The cloud on the map - smoke, dust, radioactive particles and water vapor drifting downwind - is a simplified illustration of direction and order of magnitude, not a validated dispersion model.
Open-Meteo (open-meteo.com), current wind direction at 10 m.
What this is not
- Not a prediction of a specific attack or its outcome.
- Not an official risk assessment or military analysis.
- Not peer-reviewed. The figures serve order-of-magnitude understanding.
We are looking for a physicist or researcher to review and calibrate the coefficients. If you can do this, or know whom to ask - get in touch. One expert name here is worth more than any marketing.
The legal framework
The rules the simulation prints after the strike were not invented for a game. They are principles of international humanitarian law - the 1949 Geneva Conventions and Additional Protocol I of 1977: distinction between combatants and civilians, proportionality, precaution in attack, protection of the wounded and of medical personnel, protection of cultural and religious property, the ban on means that cause unnecessary suffering, and special protection for children.
The simulation does not grade the player. It shows something else: with a weapon of this magnitude those rules are not broken by an error in execution. A fireball does not tell a barracks from a school, and fallout does not respect a border - there is no yield, no target and no circumstance that would leave the list empty.
What the International Court of Justice said
In its advisory opinion of 8 July 1996 the Court held unanimously that any threat or use of nuclear weapons must comply with the rules of humanitarian law, and that such use would generally be contrary to them. The Court split, however - seven to seven, decided by the President's casting vote - on the extreme case of self-defence in which the very survival of a state is at stake; there it reached no conclusion either way. We state that distinction deliberately: the opinion is often cited as an outright ban, and it is not.
The Treaty on the Prohibition of Nuclear Weapons
The TPNW prohibits developing, possessing, using or threatening to use nuclear weapons for the states that have joined it. It entered into force on 22 January 2021 and has around 75 states parties, with a further 25 signatories that have not ratified. No state that possesses these weapons is among them. Check whether your own country is among them.
Geneva Conventions and Additional Protocol I (ICRC); International Court of Justice, advisory opinion of 8 July 1996; Treaty on the Prohibition of Nuclear Weapons (UN, 2017) - signature and ratification status as of late 2025.
We would like this section reviewed by someone who works in international humanitarian law. If that is you, or you know who to ask - please get in touch.