The gom jabbar is a fictional weapon from the Dune universe created by Frank Herbert, appearing in his 1965 novel Dune and its adaptations. It is a poison needle tipped with "meta-cyanide" that is used by Bene Gesserit Proctors in their death-alternative test of human awareness.
In Dune, Reverend Mother Gaius Helen Mohiam uses a gom jabbar to test Paul Atreides just prior to his departure to Arrakis. This "humanity test" is carried out with a box that produces pain by "nerve induction", causing intense and severe pain without inflicting any physical damage. Only a human is considered to be able to possess the self-discipline to withstand this pain and resist the urge to take their hand out of the box. A person who withdraws their hand is stung with the gom jabbar, causing instant death.
| “ | Stop! I hold at your neck the gom jabbar ... the high-handed enemy. It's a needle with a drop of poison on its tip ... It kills only animals. | ” |
| — Mohiam to Paul, Dune (1965), Frank Herbert |
Later in the novel, Paul's sister Alia uses a gom jabbar to kill the Baron Vladimir Harkonnen. Paul next uses the gom jabbar as a pointed analogy when he tells Mohiam, "I remember your gom jabbar. Now you remember mine - I can kill you with a word."