Nukes, MAD & nuclear winter
Nuclear weapons are a doomsday lever: sub-launched warheads guarantee a second strike, first use triggers mass retaliation, and enough detonations plunge the whole world into nuclear winter.
How it works
A country's usable arsenal is nukeCount = land nukes + submarine nukes, and those submarine warheads survive a counterforce strike to guarantee retaliation. Each incoming warhead faces an interception chance = 0.06 + milTech × 0.008 + ABM × 0.45 (capped at 0.92), so missile defense and ABM systems blunt but never fully stop a salvo.
First use is catastrophic diplomacy: every other nation's relations with you snap to at most −65 and you're branded a nuclear pariah (stability −6). Then MAD kicks in — the top 3 nuclear powers connected to the target each fire back roughly 40% of their arsenal, and other powers pile on with a 45% chance to declare war on you.
Detonations accumulate globally. Once total detonations pass 15, nuclearWinter() begins; severity climbs toward detonations / 1000 (maxing near 1000 warheads). Each quarter it shaves GDP by 0.8% × severity, cuts food stocks by 4.5%, and drops stability — clearing naturally at about 100 detonations per year.
Formulas
nukeCount = landNukes + subNukesinterceptChance = clamp(0.06 + milTech × 0.008 + ABM × 0.45, 0, 0.92)each of top 3 powers fires max(3, ceil(arsenal × 0.4))sev = clamp(detonations / 1000, 0.02, 1.2); gdp × (1 − 0.008 × sev) per quarterKey numbers
How to play
- ▸Submarine warheads are your second-strike insurance — a counterforce hit can't wipe them out, which is what makes MAD credible.
- ▸Never fire first casually: relations with the entire world crash to −65 and you become a pariah, on top of the retaliation.
- ▸Build ABM and military tech if you fear a strike — interception tops out at 92%, so defense matters but can't save you from a big salvo.
- ▸Watch the global detonation count: past 15 the world tips into nuclear winter that drains every nation's GDP and food for years.