Repeating Cubic Grids (RCGs)

[Archivists note: Transcript of a printed document on 8x11 paper. Author's name is currently unknown. Main body font was Times New Roman. Footnotes were in Courier font, and appear to be written by a different author. Document feels incomplete, we are currently attempting to track down more pages.]

When it comes to the geometric features of the Underworld, Repeating Cubic Grids (RCGs) are among the most studied. The name RCG, coined by the House of the First Cartographers, does most of the heavy lifting, as this feature is, at face value, simply a structural grid of "cubes". 

Each cube contains a spliced section of an Overworld. A "copy/pasted square" as referred to by the controversial, but ever growing House of the New Guides. The cubes within an RCG are always the exact same size, though the "copy/pasted" content within might vary and evolve¹ slightly as you move throughout the grid. Individual cubes have been recorded at 1.3 cubic millimeters in size, all the way up to 72 cubic miles (the largest known overall structures have been recorded up to 47,345 cubic miles in total size²).

It is important to note that "Repeating Cubic Grids" is a bit of a misnomer, as not all RCGs are made of purely cubic shapes. Three dimensional interlocking shapes of many forms have been mapped. Including but not limited to: triangular, rectangular³, and hexagonal prisms, truncated octahedrons, rhombic dodecahedrons, and many more. There are even reports of an RCG where each volumetric "cube" is shaped like a gnarled hand with triple jointed fingers. How such a complex shape is "perfectly interlocking" has not been explained to me in a way that makes sense. 

Some people claim that our entire universe (both Overworlds and Underworlds included) is simply one cube in a much, much, larger RCG. Proponents of this theory often clumsily attempt to use the many-worlds interpretation as "evidence", but this simply exposes a severe lack of understanding when it comes to both RCGs and quantum physics.

Expect to read more on RCGs and Old House Cartography in my upcoming book: Cubes, All the Way Down⁴.

¹evolve: This simply means there can be slight variants in detail that gradually change as you move throughout different cubes of the structure. For instance, if a red house is located in one cube, then, in an adjacent, orthogonal, above and/or below cube, that same house may be a slightly different shade of red, and so on. The more cubes down the line you travel, the more the red house changes. A veritable game of telephone, in which the house may no longer be red, or even be a house at all. See the First Tower Paintings on display at the University of Westylvania for a visual representation of this. To summarize: the term "evolve" is not to be conflated with "moving rooms" or "living wings". So far, all mapped RCGs have been completely static.

²47,345 cubic miles: This particular structure, made up of cubes 42 cubic miles in size, is referred to as "Repeat City u12" by the House of the First Cartographers, who claim the full structure is actually much larger in size. "47,345 cubic miles" only refers to how much has been mapped so far. Estimates have put it up to 7.57 x 10⁸⁹ times larger. Not even the Base Cartographer herself has lived long enough to map even 1% of such an incomprehensibly sprawling structure.

³rectangular: The "Super Market" also referred to as Pagan's Produce or Pagan's Pantry, is a relatively well known "rectangular RCG" and one of the most dangerous wings of Old House (not including sections of the Deepest Cellars and Red Sun Overworlds). On top of being a barbed hook, the Super Market is home to some of the oldest known anchors in all of Old House. And much of its reported "human" population was born within its walls. The Super Market, if the Heretic's Writ is to be believed, contains entire civilizations, religions, death cults, and even evolutionary branches–bizarre species said to be distantly related to house sparrows, mice, and any other small animals that might sneak their way into a grocery store. Animals apparently transformed by billions of years of natural selection to thrive within a sunless and brutal ecosystem. I am currently searching for a complete copy of the Heretic's Writ, and open to any leads. If the stories are true, it details cultures and religions inspired solely by what can be found inside an early 2000s North American supermarket. Cultures who view this Super Market as the real world, and our world as an ephemeral and supernatural "afterlife" which may or may not exist. Anthropologically speaking, it seems an interesting, albeit likely fictional, read.

⁴Cubes, All the Way Down: Book doesn't seem to exist.