Item from Dune by Frank Herbert
Nuclear weapons held by each Great House as a deterrent — their use against humans is forbidden by the Great Convention, but Paul Atreides used them to breach the Shield Wall and changed everything.
The Great Convention is simple: Houses may possess atomics, but any House that uses them against human targets will be annihilated by the combined forces of every other House. Mutually assured destruction, codified into law. The atomics serve as a deterrent — a guarantee that no House can be completely destroyed without triggering civilizational consequences. Paul's use of the Atreides family atomics to blast through the Shield Wall was the most audacious legal maneuver in Imperium history. He targeted geological features, not people — technically compliant with the Great Convention. The blast opened a passage through the Shield Wall, allowing his Fremen army (riding sandworms) to pour into the Arrakeen basin. By the time anyone could argue the legality, Paul held the capital, the spice, and the Emperor. The precedent terrified every Great House. If the Convention could be circumvented that creatively, it wasn't the deterrent they'd believed. The rules of the game had changed, and Paul had changed them.
The weapons themselves vary by House — warheads of various yields stored in sealed vaults, maintained by specialists who hope they never have to deploy them. The Atreides atomics were concealed during the move from Caladan to Arrakis. The detonation is what you'd expect: blinding light, mushroom cloud, shockwave, and the characteristic radiation signature that every monitoring station in the Imperium is calibrated to detect.
Also known as: House atomics, nuclear weapons, the family atomics