Absolute order brings absolute harmony, at least in the Clockwork Nirvana of Mechanus, the most orderly plane in all the multiverse. There is no subtlety or guile present in this plane of stark truth and fact, but neither is there passion or emotion. Everything moves and happens with deliberate and driven purpose according to a plan. However, most, including many of the residents and gods, are blind to that plan.

Mechanus is a plane filled with enormous gears, like the internal working of a clock, each gear moving in perfect concert with adjacent gears. Some gears are as small as 10 feet across, while most are larger, spanning hundreds or thousands of miles. They all move, though many are so expansive that their movements are imperceptible to those moving and living on them.

In this plane of constant motion, of gear teeth moving with absolute precision, everything is in perfect balance. Day and night, light and dark, they are all parceled out in equal portions without change or deviation. The sheer scale of the operation on Mechanus is mind-boggling and has thus far eluded attempts at deciphering, though some have dedicated their lives to understanding its meaning. The Confederacy of the Cog is a group of brilliant artificers who are wholly devoted to understanding not just how Mechanus works.

Life exists in the Clockwork Nirvana, though most of it is mechanical or constructed in nature. The most numerous and recognizable of Mechanus’ resident races are the modrons – legions of geometrically shaped creatures living, breathing, and operating to keep Mechanus ticking and running smoothly. From the spherelike monodrones to the cube-like duodrones, all the way up to their supreme god, Primus, they are all devoted to keeping the gears running. They don’t know why, they don’t care why, and usually, they only have the barest hint at what exactly their duties accomplish. But they accomplish them with focused intensity and child-like glee.

Mechanus' clockwork precision is not just found in the continually running gears and moving pieces. There’s a sense of rigid order that pervades every facet and affects everyone equally who travels its realm of endless gear. The regular variance of chance is dampened to an extreme degree, so that the predictable outcome is the most likely, even in an otherwise unpredictable situation.

There are other, stranger manifestations in this plane of absolute order. The Word of Law is an enigmatic figure that twists the natural power of Mechanus into immensely powerful written words, like scrolls. Few have seen this strange being face to face, and most believe it is an entity from another plane pushing into the Clockwork Nirvana. The Glass God is another one of these powers, though its origin is more overt – it comes from the Far Realm. It seems to be enforcing a kind of unknown, alien order into the rigid structure of Mechanus, spreading and infecting out like a disease.

It surprises some to learn that there are portions of Mechanus devoted to junk and refuse, along with the raw materials that make up the gears. These are, of course, all perfectly orderly and organized, and the modrons that tend to them and many other realms in the Clockwork Nirvana take their jobs very seriously. They have strict rules preventing outsiders from taking scrap or raw materials outside the designated zones.

The great machine of Mechanus is constantly moving, in perfect synchronization with countless delicate gears across hundreds of thousands of miles. Or at least, that's the image. The reality is that there are any number of parts that break down across the gear landscape, and a great many outsiders work to harvest the valuable metal for their own purposes. Mechanus exists as the pinnacle of order in the multiverse, but it is not perfect, and there are plenty of cracks in its façade for many to exploit.

Getting There

Portals and gates leading to Mechanus never randomly appear or disappear. They may have extremely long cycles of inactivity, but they always operate on a regular schedule in cadence with the cog they lead to on the plane. A gate leads to the center of a specific cog somewhere in the Great Gears, and its opening is tied to the movement of the interlocking gears. Some may open for a minute every hour, some open for an hour every day, while some open for exactly 13 minutes once every decade.

Without the greater context, the opening of these gates can feel random, but anyone who knows Mechanus knows that it is anything but haphazard. It simply requires a wider understanding to fully grasp.

Portals to the Clockwork Nirvana are normally marked by a constructed archway of some sort, usually metal, often containing a gear-like pattern on the surface. Opening these portals usually requires completing a set of verbal and somatic gestures within 5 feet of the opening while possessing a small cog in hand. Aspects of the ordered regulation of Mechanus often bleed through the multiverse, and it’s not uncommon to have buildings of industry built around these portals, regardless of actual knowledge of the portal’s presence.

There are certain gates that are activated by events that occur on regular schedules. The most widely known of these are the gates along the path of the Great Modron March. During this time, the modrons of Regulus march across the multiverse in a massive line, following a predetermined path that flows through multiple planar gates. As with everything on Mechanus, the Great Modron March occurs on its own ordered schedule, but few have the scope of knowledge to understand that schedule.

Traveling Around

For a plane of moving gears and grinding cogs, movement around Mechanus is surprisingly straightforward and easy. Everything in Mechanus is connected to something else, usually gears connected to adjacent gears via cog teeth, so it’s possible to reach any destination in the Clockwork Nirvana from any starting point. It may take some time, but there is a path.

Part of traveling around Mechanus is moving along the faces of the gears. A person standing on a gear is standing upright, but gravity is situational, so that same person could step onto an adjacent perpendicular gear and orient immediately to the new “up and down” without any ill effect. This all makes moving physically relatively straightforward, and it’s coupled with the fact that the movement of the gears – all are in motion – are not felt by a person or object on the gear. Nothing flies off, regardless of how fast the gear is moving.

Because of Mechanus’ three-dimensional landscape and no set horizon, concepts such as north, south, east, and west do not make sense on the plane. Instead, the entire plane is divided up into an infinite coordinate system developed by Primus, the god of the modrons and one of the oldest beings in the multiverse. Using the magnetic obelisks around Mechanus along with devices that resemble sextants, a person can find out where they are on the great grid of the plane, a location identified by three numbers known as the exx, wyy, and zee. Primus, in the center of Regulus, is at 0,0,0, and the numbers increase out to infinity from there. They can be negative or positive reflecting the relative direction from Primus.

Every site and gear in Mechanus has coordinates on the exx-wyy-zee grid relative to its distance to Primus. Every 1000 feet is marked with 1, so the point 1,1,1 is 1000 feet from Primus in three directions, while -1, -1, -1) is 1000 feet from Primus in three directions in the opposite direction. To the modrons and other natives of Mechanus, the coordinate system of exx-wyy-zee makes perfect sense, and they have a hard time adjusting to the relatively flat landscape of the rest of the multiverse.

Lay of the Land

Mechanus consists of a single layer, infinite in size across all directions, with no natural ground to be found. Everything is manufactured. One particularly strange aspect of Mechanus is the gravity; it's subjective based on the gear you're traveling on. Many gears and cogs are perpendicular to one another, but a traveler can move from one to the other by simply stepping onto it. They are re-oriented to the new flat surface as “down" while everything else remains in place.

The effect is strange, but the natives are used to it, and the constructs that move around the plane are completely unfazed by the shift in gravity and perspective. This does mean that the concept of direction is difficult to convey, but modrons and other natives have built tools that help anchor and reference using magnetic obelisks around Mechanus (see the Traveling Around section for more details).

Though Mechanus has a single vast layer, it is divided into geographic realms, identified by planar scholars and adopted by natives for a common vernacular. The Great Gears and Scrap Tracts are all part of the vast machine of Mechanus and can help travelers navigate around.

Great Gears

The vast majority of Mechanus is comprised of a broad region referred to as the Great Gears. This is the core of Mechanus, consisting of innumerable gears and cogs, all moving in synchronization with one another. There is no region of open sky in the Great Gears, as there are always more cogs above and below any particular cog, usually within sight. The closeness of the gears makes some regions almost building-like in their structure, with moving cogs functioning as walls.

Most of Mechanus's population is found in the Great Gears, including the modrons and the factories that produce the inevitables. Some of the larger cogs are populated by transplanted populations from across the multiverse, including devilish outposts and angelic watch towers.

Scrap Tracts

Sometimes, gears break down and need to be replaced. The maintenance of the cogs across the plane is left to the modrons. They dispose of broken gears and pieces into the regions known as the Scrap Tracts. There are multiple Scrap Tracts housing the refuse and junk produced by the natural processes of Mechanus, and each one is contained in a vast cylinder of gray steel.

The cylinders are hundreds of miles across and have multiple entrances. Inside are vast collections of scrap metal from across the plane. Metallic golems patrol the interior and exterior, but each Scrap Tract is so large that it is impossible to patrol thoroughly. Scavengers of all kinds regularly raid the cylinders for parts to fuel their own purposes, the most numerous and tenacious being the Gearlost.

Each Scrap Tract is assigned a unique serial number for identification, from Alpha One to Omega Ninety-Nine. Some of them house specific types of scrap, such as Scrap Tract Gamma Eleven, where all magical refuse is contained. Finding a specific cylinder is difficult, however, as the modrons are the only ones who know, and they are forbidden from sharing this information with outsiders.

Eventually, the refuse in each Scrap Tract is broken down and turned into new gears and cogs, which are used to replace worn gears and shore up destroyed sectors. As with everything on Mechanus, there's an ordered time for this conversion, but the scale and relative isolation of the Scrap Tracts make understanding the exact timing difficult for outsiders.