Nuclear exchange rules

Nuclear weapons are the most consequential order in War Games. This is how a strike resolves in the engine.

1. Research. The nuclear track has three levels, costing 5, 8 and 10 knowledge plus 3, 5 and 8 uranium.
2. Build. Building a warhead needs nuclear level 1 and costs 10 gold and 5 uranium, or 8 gold and 3 uranium from level 2. At level 3, every warhead you build also costs each other faction 5 influence, which models deterrence.
3. Launch. You need a warhead in stock. Below level 2 the target must be adjacent to a territory you own. From level 2 (ICBMs) any territory is in range. You cannot nuke your own territory.
4. Effect. Every unit in the target territory is destroyed, whoever owns it. The territory loses its fortification, becomes unowned and its resource yield is wiped. It stays neutral with no yield until someone moves a unit in and captures it.
5. Second strike. If the territory belonged to a faction with nuclear level 3 and at least one warhead, that faction automatically fires one back at a random territory the attacker owns. Range is not checked for the retaliation, and a retaliation does not trigger another one.

Orders resolve in faction order (NATO, Russia, China) within a turn, so a strike lands before any later faction's orders for that turn are resolved.

The tech tree, costs and ranges are data you can change. See modding War Games.