Yeah, I know what you’re thinking. That’s not what it does…
A brass cylinder roughly a handspan long, and about as big around as a little finger. At the top, the cylinder pierces a twisted ring. It is incised with a well-worn images. The obverse shows a skeletonized body, greatly elongated, tied by its wrists to the top of the hoop, while the reverse shows a bound hermaphroditic figure in the same posture. The images are blackish-green at the top of the ring, fading to a deep russet black near the end, and the base of the key is also blackened badly. A thin slot is visible at the tip of the cylinder on the end furthest from the hoop.
Spoilers follow. Players beware.
The Key will detect as magic, and the discoloring stains are human blood.
Identify answers: “I fit no door; the Chest I open admits no other key.”
Botched Identify answer: “A blade from the Scissors of Atropos”
The Skeleton Key is primed by pulling gently on the ring while holding the barrel. A thin 6″ blade snaps out of the tip, locking in place until it is used. The blade retracts shortly after being exposed to blood in any case. To use it, the user stabs the Key into the abdomen or chest of a corpse and twists. Turning the Key towards the Skeleton image slits open the torso from collarbone to pubis, abruptly separating the ribs and opening the entire chest for scrutiny. Twisting the Key towards the “whole” image closes an opened chest, leaving the corpse unscarred. It may likewise be stabbed into the temple, opening the skull along its sutures. In either case, the wound caused by the blade remains even after the other wounds close.
The Key may be used as a Minor weapon, subject to the usual limitations, and is useless in any other regard against a foe with a well-armored torso/head (chain-equivalent or better).
If the user attempts to activate the Key by stabbing a living being, they must make a successful Called Shot. An affected character’s HP drops to zero at the end of the round as their torso/skull unzips, killing them instantly. The target may save vs. Poison to avoid its effect with a +2 bonus. Apply an additional +2 bonus if the character’s ribs or head are well-bound or otherwise constrained (by a corset, for example, or a tightly-wound turban).
The Key has no effect on non-Humanoid corpses or entities, and living shape-shifters are immune to its effect; they simply take 1d4 damage on a failed save.
Anatomists and other shady body-robbing types would pay handsomely for the Key. Indeed, it was one of their number, a Hessian Baron working just outside Darmstadt, who created it to aid his perverse investigations. One can only imagine how delighted a cultist leader or an Aztec priest would be to gain such an object..
Its existence is known to the Knights of the Siege Perilous and their allies in the Low Countries, and rumored in the Vatican. Possessing the Key is a crime punishable by the Stake in all lands claimed by the English Crown, under the Unspoken Acts of Parliament Assembled.
Mohammedan authorities would likely be more forgiving of its effects, but the clearly mystical engravings and great impurity of the object itself (being steeped in the blood of a thousand corpses) would leave them deeply suspicious of its owner.
To all Jewry, it is Right Out.