Gooie Kablooie

The Gooie Kablooie is the ultimate weapon. It is aimed at a whole enemy planet rather than at one baron, and your planet can only have one at a time.

Nobody buys the weapon alone. One baron starts the work and names the target planet. After that, any baron here can put money in, a million gold at a time. The price depends on the size of the target planet: aiming at a planet much larger than yours costs more.

When the last of the money is in, the weapon builds for three more days and then launches itself. Nobody decides that. The only person who can call it off is your elected Coordinator, and only before it leaves the ground. The gold is spent either way.

Being on the receiving end

A weapon aimed at your planet does not go off and disappear. It arrives, sits on your planet, and eats it. The day it lands it takes a tenth of every realm's regions. Every day after that it takes another twentieth, until five days are up and it burns itself out. Left alone it will cost you better than a quarter of your land.

Only jets can reach it. Your realm is asked at the start of your turn whether you want to attack it, and the screen tells you how many jets it would take to destroy the thing outright — a figure that grows with the size of your planet. About a third of the jets you send do not come home.

No single wave can finish it, however many jets you send. That is the point: the weapon is built to need the whole planet's air forces, and a planet that cannot organise loses the land.

An SDI program is no help against it, and neither is anything else you own.