OpenFront Water Nukes — The Land Becomes Sea, Permanently

With WATER NUKES on, ground a nuke erases does not become radioactive fallout — it becomes ocean. Fallout can be retaken, expensively. Sea cannot be retaken at all.

In the code it is a single branch in one function: off, it lays fallout; on, it queues the tile for water conversion. So cost, radius, and troop damage are all identical — the only thing that changes is what is left behind.

A lobby option, off by default. It also appears as a label on public lobby cards, so you can check before joining.

Fallout versus sea

That ×5 is the same multiplier a defense post applies. So with the option off, a nuked strip becomes ground nobody wants to enter for a while, and eventually somebody pays to take it. With the option on there is no such negotiation — the land is off the map.

The usual warning about nuking ground you intend to take yourself (see when to use nukes) gets much sharper here. Off, you pay extra. On, you can never have it.

The blast shape changes

Not a number, but visible immediately on screen.

Off (fallout)    inner radius   always erased
                 outer ring     50% chance per tile → speckled scatter
                 connected tiles only (never jumps a blocked gap)

On (sea)         inner radius   always erased
                 outer ring     a different radius sampled per direction,
                                then smoothed → one solid, wobbly-edged crater

The reason is written into the code: speckling would leave scattered land fragments that a player would have to boat to individually to reclaim. With fallout the fragments stay connected by land, so it does not matter. Once they are surrounded by sea, each one needs its own amphibious landing. Hence solid craters.

On average the two remove the same number of tiles. Only the shape differs.

Because the outer ring is a coin flip per tile, it contributes far more area than the guaranteed inner circle. Thinking of an atom bomb as “452 tiles” counts about a quarter of the real footprint. The nuke calculator fills in these averages for you.

The new sea is navigable

It is not decoration. Once the conversion flushes, the game rebuilds its water pathfinding graph, so ships use the new ocean.

• Landing sites appear where there were none. An inland border that suddenly becomes coast is a border transports can reach (see stopping amphibious landings)
• Warships get in. Their 130-tile reach now covers ground it could not touch
• Land bridges can be cut. A hydrogen bomb across a narrow isthmus severs the ground connection outright — and severs it for you too if you needed that corridor

Impassable terrain does not convert. Water nukes skip those tiles, so the impassable terrain introduced in v0.33 survives any warhead — a blocked corridor stays blocked no matter how much is thrown at it.

Interaction with the Doomsday Clock

If DOOMSDAY CLOCK is on as well, there is one real interaction. The clock’s required tile count is proportional to the map’s total land, and water nukes genuinely reduce that total.

So every water nuke lowers the bar for everybody. Your holdings can stay flat while the requirement sinks beneath you into safety. Conversely, a water nuke on your own ground deletes tiles outright and pushes you under — and unlike fallout, there is nothing to retake to fix it. Details in the Doomsday Clock guide.

What changes in how you play

In one line: with the option off a nuke is a weapon against troops; with it on a nuke is a tool for editing the map. Troop damage itself is identical either way, so the nuke calculator applies unchanged.