• Government Type: None
• Symbol: Unknown
• Major Races: Undead, Elves (Drow), Dwarves (Duergar), Elementals
• Capital: None

The Null Labyrinth is impossible to map, as there are no fixed landmarks or environments save for the cities. Locations move and shift constantly, and space as we know it within this underground realm is more of a suggestion than a law.

The Null Labyrinth does not exist fully within the plane of Cahyali, and is anchored to the plane through ancient magic or technology. There are only a few fixed or 'stable' locations that do not change in the labyrinth, and all other locations are in flux. Permanent residents of the Labyrinth have studied and have an innate understanding of the rhythm of the changes of the labyrinth, and as such are able to travel through the labyrinth somewhat easily. Explorers and adventurers regularly hire such guides on their expeditions.

Overall, the Null Labyrinth makes up a massive cave system stretching across most of known Cahyali, and likely even past Esrior's Fold. Some have theorized that traveling through the Null Labyrinth is one of the ways to pass the Fold, but navigating the Labyrinth is nearly impossible even for those who live within it. The less anomalous underground realms of Buyuk and Itlan-Youali connect to the Null Labyrinth, though very few residents of either world venture into the Labyrinth's depths.

The environment of the Labyrinth is surprisingly alive for such a strange place, with caverns lit by glowworms and bioluminescent fungi. Living residents subsist on fungi, and the few odd sorts of fauna who live down here. In places, the cave ceiling is so high that fog can develop from activities of life below… giving the space above something resembling a sky.

Over half the population of the Null Labyrinth is undead, although the restrictions applying to most undead seem to be - well - null down here. For example, vampires within the Null Labyrinth do not rely on blood to live, and preserved undead such as mummies do not fall apart over time like they do on the surface; this applies even to temporary visitors. Many believe that the Arcane Font provides energy for these undead and allows their rather peaceful existence.

While the settlements of the Labyrinth don't count these into their populations, many of the caverns' wilder areas are haunted by undead without minds or selves; undead that appear not to benefit from the strange vitalizing properties of the Labyrinth and attack living beings on sight. These types of undead, termed “hollow ones” by Labyrinth residents, are strikingly more common near ancient ruins.

The living residents of the Null Labyrinth are primarily elves and dwarves. These individuals have adapted to the environment over centuries, and are markedly different than their surface cousins. It is thought that the first populations of elves and dwarves arrived in the Labyrinth tens of thousands of years ago, and a small yet steady stream of new arrivals has been coming ever since. Termed drow and duergar, respectively, they mostly have white or light gray hair, skin in desaturated shades of gray, blue, and purple, and keen eyes with red or white irises.

Elementals are also common here, with many children being born touched by the different planes. Most simply attribute this to an effect of the Arcane Font. Minority populations of most other races exist in Labyrinth settlements, though none have been here as long as the drow and duergar have - many arriving, at earliest, during the era of Imperial Dahabu in an effort to escape from the invaders.

There a few known fixed locales within the Null Labyrinth that explorers have charted. Many appear to be remnants of an ancient civilization, so old that not even the most ancient, crumbling undead residents know much about it. The architecture of these landmarks is similar, and bears no resemblance to any other Cahyalian style.

Null Caldera: The caldera of an ancient volcano, where the ruins of the Arcane Forge are located. Directly beneath is the Arcane Font. A fixed location, located about a thousand miles off the cost of Ley'Ork underneath Ulosian territory.

• Arcane Font: A hidden and guarded well of magic that leaks forth from a different plane, a source of extraplanar power. Believed to be one of Cahyali's few leysprings: a massive source of arcane energy. Some scholars posit that the effect of the Arcane Font is what gives the Null Labyrinth its abnormal spatial properties.

Ruins of Tarra: What remains of an ancient city, long deserted. Believed by archaeologists to be a remnant of an ancient civilization, perhaps the first to ever inhabit the caverns. It is now haunted by spirits and malevolent, mindless undead, and deep within are rumored to be the ancient controls to the Null Labyrinth. A fixed location, approximately underneath Dahabu's Al-Kharshi Bay.

To date, no adventurers or explorers have managed to breach the deepest levels of Tarra and reach the controls. According to legend, these controls are magically linked to the Arcane Font and allow a precise level of control over the Labyrinth's spatial anomalies. None know what form the controls take, however, or how they're operated.

• Mycas Fields: A giant cavern, about 150 miles across, filled with a veritable forest of giant fungi. These fungi are growing on an organic substrate of unknown composition that defies logic and identification.

There are a few cities that can be found in the Null Labyrinth, each of which operates as a city-state with its own laws and customs. These cities are some of the few fixed locations within the Labyrinth, anchored to a single point in space through unknown means. Most cities are lit by arcane means, though some intrepid individuals have brought electricity back from the surface. Geothermal energy is commonly used to power these devices, and many cities have “furnaces” digging deep into the earth and drawing up its heat.

• Void’s Crossing: city belonging to the Null Cultists.
• Manilla: City belonging to a sect of Null Cultists who have lost faith.
• Abberath: City of elves and dwarves who have been shunned from the surface eons ago and now have adapted to the labyrinth. Located within the Mycas Fields.

Running Null Labyrinth: Outdated document on the general structure of the Null Labyrinth.