Stunner

In some science fiction works, a stunner (and all its myriad synonyms) is a purportedly humane firearm which renders its targets unconscious without killing them or doing any undue damage to their bodies.

Stunner in Earthgrip
Jennifer Logan was used to the stunner from her various merchant trips to hazardous planets.

Stunner in Noninterference
Stunners were the preferred weapons of the Federacy Survey Service, who sought to avoid damaging the peoples they studied any more than necessary. However, in 2688 FSY, Roupen Hovannis, a powerful Service officer who was complicit in criminal activities, modified a stunner to be a lethal weapon. His goal was to assassinate Sabium, the Queen-Goddess of the Helmandi Empire, whom the conspiracy perceived as a living proof of the Service's consummate failure. Hovannis killed a guard at the Mawsil gate and Bagadat the majordomo, but was unable to kill his prime target.