Basically, it's my personal, dungeon-room homage to the movie Prestige (2006).
"Who could have ever anticipated that messing with a cloning machine in a dungeon would lead to tragedy?"
Like the Deathgate Puzzle Room, I posted earlier, the Cloning Machine was designed for use in my Skull Mountain megadungeon campaign I ran a few years back. And like a lot of my favorite dungeon setups, it is absolutely safe - so long as the PCs don't mess with things that are obviously dangerous. Of course, adventurers never seem to be able to resist such temptation...
The basic setup is simple: Two rooms separated a bit in the dungeon. The first room houses the cloning machine itself, an ancient and dangerous device manufactured by some mad wizard centuries ago. The second room, the cloning vats, are where anything cloned or created by the machine appear.
Room #1 - The Cloning Machine
A large domed chamber. Iron pillars, 30' tall, arrayed around the wall, carved with a thousand strange symbols, and topped with metal balls. At the center, an altar of some sort. It is carved from a solid stone block, and stands about waist high...
The altar looks something like this.
Above the altar, mounted high on the ceiling, is a strange crystal, pointing down, directly at the altar below...
The great crystal hanging from the ceiling...
On the front of the altar, is a bronze dial with six symbols carved in the stone around it. The dial can be turned about to six different "settings," one for each symbol.
When discovered, the dial is set to the stylized "O", which is the "off" setting. After each use of the machine, the dial returns to this setting, until the PCs tamper with it again.
Room #2 - The Cloning Vats
The second room is simply a large chamber full of glass tanks, each 12 feet tall, all filled with some kind of strange, purplish liquid. Each tank is connected to the ceiling by a series of strange, rubbery tubes, and each has a metal "door" that can be opened by turning a small wheel. Opening a tank causes the liquid within to come pouring out, but each tank, unless damaged, refills whenever the cloning machine is activated.
Kind of like this, but in a dungeon, not high tech...
Activate the Cloning Machine at Your Peril!
Activating the machine is simple - you just turn the bronze dial away from the "O" setting to one of the five other symbols. As soon as the dial stops on a symbol for a few seconds, the crystal above will begin to glow, hum ominously, and bathe the altar below in a ruddy light. The walls and ceiling seem to fall away, revealing a strange, starry sky, whirling and bursting with planets, large eyes, silently floating shapes of hideous proportions, and other horrors.
What happens next depends on which of the six "settings" you set the machine to. Here's what they do, working around the dial clockwise...
(1) Stylized "O" – the "off" setting.
(2) Weird Thing that Looks Like an Hourglass – If any living thing is lying upon, or touching, the altar when the machine is turned on and the altar is bathed in red light, the machine summons one exact copy of that being from the future. The duplicate appears, with crackling energy and fanfare, in a random cloning tank. The future self of the character is only from a few hours in the future, and played by the GM as an NPC. The future self likely has some additional knowledge of the dungeon, but is cagey. An hour or so after the duplication, the "past" or "original" character simply vanishes...and the player takes over the "future" version.
(3) Symbol that Looks Like Three Guys Conferring – Summons 2d4+4 doppelgangers from alternate time-streams that look and act like the person on the altar – except for the fact that they are naked when they appear, act sly and strange, and - oh yeah - hunger for human flesh. They have only limited knowledge about the person they look like, and so pretend they have amnesia.
(4) Symbol that Looks Like Heads on Stakes – This is a fail-safe created by the maker of the machine, in case things got out of hand. This setting summons nothing to the cloning tanks. Instead, as the machine is activated, it summons 1d4+2 Bodaks, Dimensional Shamblers, Invisible Stalkers, or your preferred inter-dimensional monster, which appear around the altar, attempt to slay all life within sight, and then vanish – carrying away the remains back to their home plane.
(5) Dudes Gathering Around a Crystal – This summons 2d4+4 copies of the character touching or lying upon the altar, which appear in the cloning tanks. These are actually copies of the "cloned" character pulled from other, quite similar parallel dimensions. However, astute observers will notice small, subtle differences, such as the way the person styles her hair, key details of her background, etc. All of the "clones" are self aware, played by the GM, and want very badly to return to their home dimensions. They are quite willing to try and force the PCs to tinker further with the cloning machine, in the hopes they can find a way home.
(6) Two Guys Looking Down on a Dead Guy – This is true cloning, and summons 1d4+8 exact copies of the target's body into the cloning tanks. Unfortunately, these clones are simply empty vessels, without minds, and do nothing but lie there, drool, and soil themselves. Eventually, unless cared for, they will die of starvation, thirst, or exposure. But, if the "original" dies while any of these clones are still alive, there is a 75% chance that the original's soul will drift into one of the clones, and avoid death. (In my own game, this was one of the few ways a character might cheat death - no Raise Dead spells here).
Epilogue: The Cloning Machine In Play
In my Skull Mountain campaign, the PCs only encountered this room once - and thereafter avoided the entire area at all cost!
Uncertain as to the machine's purpose, the PCs decided to begin with a little "animal testing." So, they grabbed a sheep one of the characters had dragged into the dungeon (to help check for traps), strapped it to the altar, and flipped the dial to result #3 above. Soon, they had 9 identical sheep. Except that the 8 new "sheep" seemed awfully clever and, ultimately, turned out to be carnivorous doppelgangers....
"Did we just make a bunch of man-eating, interdimensional doppelganger sheep?"