The Black City: Grey Technology, Treasure and Artifacts

Any sufficiently advanced technology is indistinguishable from magic.
-Arthur C. Clarke

Before I start putting up some of the hex content charts or dungeon levels, it makes sense to publish some notes on the magic and technology used by the ancient builders of the Black City (at least, the types of things that might have survived thousands of years amidst the rocks, ice and snow).  The builders of the city were an alien race (modeled after the Greys of UFO folkore) that came to the earth tens of thousands of years ago during an interglacial period of the last Ice Age.  During their stay, they experimented on primitive hominids and terrestrial life, and then vanished overnight in a cataclysm of their own making, leaving the city empty.  The technology they brought with them was built on sorcery and arcane science, and became the foundation for the mortal magic used by the prehistoric Hyperboreans when it was rediscovered in later times.

Doors in the City
Most doors are hatches that slide on grooves into the wall.  A few areas in the city are still connected to the ancient power generators (located deep under the mountains north of the city) and the doors will open and close with the proper color-coded pass key gem stone.  These locked doors will be noted in the room text.  Everything else will need to be forced.

Doors will slide into the wall if forced with a standard open doors check (it's expected the group is using a crow bar or similar pry bar, otherwise the check is at -1).  Like standard dungeon doors, hatches will slide shut behind the party unless blocked.  Knock spells will pop open a stuck door.

Gemstone Pass Keys
Small, inexpensive gemstones are the ubiquitous currency of the raiders, because they are very common in the ruins.  The reason is simple; each citizen of the city had a gemstone embedded in the palm of the left hand, and these gems controlled access to the city doors.  (The Greys were a cloned race, grown in vats, so their "caste" and associated gemstone color was determined at birth).  When they died in place, these minor gems were left behind everywhere.

I like the whole "visible light spectrum" for grading the security pass codes, so the lowest security level doors will be opened with the most common embedded gemstones, the red ones.  Areas that still have power are likely the most secure and will require the rarer blue or purple gemstones.

The party will be happy that much of the treasure is so portable, and would hopefully be disturbed when they realize that each of the gems they're scavenging were once embedded in a living alien.

Crystals
Machined and cut crystals are another common treasure type.  Crystals were used as fuses, holographic storage, and memory chips.  (Miniaturization need not apply to arcane computers).  Trial and error may yield some results if groups experiment with the various crystals they've picked up when they encounter appropriate work stations and crystal readers.

Crystals bring that 'Fortress of Solitude, I am your father, Jor-El' vibe to the alien technology, along with reminding me of the Sleestaks and their pylons and matrix tables.

Magic Items
As decadent sorcerers, the Greys used various wands, rods, and rings - I see the wand of magic missiles or the wand of paralysis as a staple item.  However, to give them a 'tech' feel, Grey magical artifacts will use arcane batteries instead of embedded charges.  Players will be able to find these simple battery cylinders from time to time, and make interesting resource choices about which items to power up or unplug.  More powerful items will drain batteries faster.

As a nod to classic Trek, one magic item pair will be the slave collar and emotion ring (a kind of mind control / suggestion / inflict pain device).  There are also levitation discs that can be attached to items to reduce gravity, making it easy to move large objects around the city or float up and down open shafts.

Automatons
The ancient Greys despised physical work - they enslaved primitive races or built servants using magic.  There are three classes of servitors in the city - living statues, plasticals, and golems.  These three groups will get a more detailed write-up in a bestiary article, but here's a quick overview.

Living Statues
Living statues are typically crystal, iron and stone; most of them are shaped like 8-legged spiders or giant scorpions.  Crystal spiders are the most common, especially in the warrens of decay, still performing mundane repair tasks.  Packs of them click along the cavern ceilings scurrying from place to place.

Plasticals
Plasticals were skilled laborers made by the Greys in their own image - they are rubbery, with bulbous heads and large, almond shaped eyes, naked and sexless.  I'm thinking of modeling them after the "Magen" from X2, Castle Amber.

Golems
Iron and stone golems are the heavy duty guards and defenders of the most important locations within the city - they'll have oversized heads, elongated arms, and bulbous eyes (like their creators) and many of them will have four arms instead of two.

Note:  much like the Greys themselves, all of their servitors were embedded with gemstones to allow door access; these minor treasures can be recovered when the servitor is smashed.

Precious Metals
My thoughts here are still evolving - silver was plentiful to the Greys, and many common implements that could be made of metal were done from silver and can still be found in the ruins.  I'm considering that gold and platinum squares might have been used for machine management like old computer punch cards and can modify how some of the still-working machines operate.

Standard Treasure
Other cultures have explored parts of the city - the ancient Hyperboreans found the city across an ice and land bridge at the end of the Ice Age, and a lost Roman fleet discovered the city only a few hundred years ago (and perished in the ruins).  So there are opportunities to find treasures and cultural artifacts of these earlier human cultures (including the traditional gold coins and more common magic items you'd expect in an old hoard).  And the many Viking raider groups that have entered the city over the past few years, and died in the ruins or become worm-infected Berserkers, have left "modern" weapons, armor and loot behind, as well.