The Lazy Gun

From the book, Against A Dark Background, written by Iain M. Banks, author of The Culture series.

This gun is possibly sentient, but certainly intelligent. You point the gun at the thing you want to kill and it kills it using a random (often comical) method. E.g. sometimes it will set the person on fire, or it may teleport a cow above their head, or disassemble them at the quantum level, or tell them a joke that is so bad their spleen throttles their brain.

It’s a farcical weapon created by an extinct alien race to show off their infinite technical ability. Nobody really knows where it came from and there are only a handful of them left in the galaxy.

Features:

• It has an optic at the front that presumably gathers information about the target in order to decide how to kill them. By the way, the object can be anything, from a tomato to a planet. Apparently someone tried to shoot the sun with one and they and the gun were never seen again. Any attempt to backwards engineer the gun causes it to self destruct, taking out whoever is looking into it. Some scientists tried using a machine to look into it while they were at a safe distance, so it annihilated the whole building complex with them in it.
• It weighs differently depending on its orientation suggesting that there’s some interdimensional weird quantum higgeryjiggerypokery going on inside. Its mass is therefore undefinable. Its inner workings a mystery.
• Randomness of death is reduced as objects get larger. For example, point it at a city and it’ll usually just nuke it.
• There are no known instances of the gun being fired at a sensible object and its existence continuing. The gun never fails but it can backfire if you try to mess with it or misuse it. The gun has a bad attitude and doesn’t give a fuck about the target nor the one wielding it (nor even its own existence which is probably why there are so few left).
• Because of its chaotic nature and pure destructive power, the Lazy Gun is illegal in all known jurisdictions across the galaxy. If you own one, the government will probably confiscate it from you just so they can have it for themselves. Think of the Lazy Gun as being the Steam Punk equivalent of the Ring of Power while high on cannabis and cocaine.