Improvised nuclear devices or (INDs) are theoretical illicit nuclear weapons bought, stolen, or otherwise originating from a nuclear state, or a weapon fabricated by a terrorist group from illegally obtained fissile nuclear weapons material that produces a nuclear explosion.

A suitcase nuclear device (also suitcase nuke, suitcase bomb, backpack nuke, snuke, mini-nuke, and pocket nuke) is a tactical nuclear weapon that is portable enough that it could use a suitcase as its delivery method.