The Vortex Grenade is an extremely rare and advanced type of specialised grenade used by a few, select individuals in the Warhammer 40,000 universe. The grenade opens a "hole" to the Warp in realspace, which destroys any troops caught in its area of effect. The Vortex Grenade is also an unpredictable weapon in the fact that it not only destroys anything that it comes into contact with, but also that the Warp vortex it creates drifts randomly after activation, slaying friend and foe alike. Vortex Grenades, as a result of the ancient arcane technology used in them, are very difficult to produce, as might be imagined. Only the most specialised and advanced Adeptus Mechanicus Forge Worlds still retain the technical knowledge required to manufacture them. As a result, these unpredictable weapons are only made available to the most high-ranking of Imperial servants, such as the senior officers of Space Marine Chapters, agents of the Officio Assassinorum and Inquisitors.
The Vortex Grenade takes the form of a weighty sphere, approximately the size of a man's fist, which consists of an outer shell which encases a delicate and temperamental Warp field generation mechanism. The designs of the device date back to the Dark Age of Technology. When the grenade is activated, it creates a tiny rift between realspace and the Warp, a rift that becomes a vortex in the very fabric of space-time. In appearance the vortex is a ball of glowing blackness like a small black hole. Everyone and everything encompassed by the vortex is destroyed; all matter and energy present is drawn through the vortex and consumed by the psychic energy of the Empyrean.
Warp vortices are incredibly dangerous, as once they are created they behave in an unpredictable and uncontrollable manner. They may shrink, expand, vanish, remain for long periods of time, move or even divide. For this reason, Vortex Grenades can prove as deadly to their user as to their intended target.
- Warhammer 40,000: Apocalypse (4th Edition), pg. 187
- Warhammer 40,000 - Apocalypse War Zone: Damnos, pg. 18
- Warhammer 40,000: Battle Manual (1st Edition), pg. 89