- A new urban system developed to cope with Catastrophes. Usually it only takes 2-8 weeks to completely evacuate from a Catastrophe area.
- A city built on a giant vehicle. The frequent and destructive Catastrophes have forced all nations to move their cities regularly to avert massive losses. The birth of the Originium engine made it possible to industrialize Originium, and that was when people started to build larger and larger vehicles. The concept of nomadic cities was realized after vehicles became large enough to move entire cities. With the help of the Multimethod Catastrophe Prediction system, it only takes 2-8 weeks to completely evacuate from the Catastrophe area depending on the situation.
The concept of a nomadic city is very straightforward: an entire city that can be moved as if it is a colossal vehicle. Nomadic cities are used by the Terrans to lessen the impact of, if not avoid entirely, the destruction caused by Catastrophes. The nomadic city is perhaps a key example of selective evolution within the setting of Arknights, as few sedentary settlements remain. The reason is clear: using Catastrophe prediction systems, a more-or-less accurate estimate of when a Catastrophe would occur, will allow nomadic cities to relocate into a safe area in time, whereas only the inhabitants of an immobile settlement can be evacuated. This is best exemplified with the eruption of the Siesta volcano forcing the city to be rebuilt as a nomadic city. Conversely, the Catastrophe that affected Chernobog is a perfect example of what would occur should a nomadic city fail to evacuate in time.
It may also be inferred that nomadic cities could catalyze economic disparities: it is more frequent for those living in static settlements to lose everything they possess. It explains why many sought refuge in the slums of Lungmen after the fall of Chernobog, as opposed to rebuilding sedentary settlements: the least fortunate in nomadic cities are still more fortunate than those who are at the mercy of Catastrophes. This further strengthens nomadic cities and weakens sedentary settlements at the same time.
Nomadic cities utilize Originium reactors to both power their engines and providing electricity to the city itself. On one hand, the magical power of Originium provides the enormous energy needed to power these tons of metal giants. On the other hand, the over-reliance on it causes suffering to the lower class via the deadly Oripathy. As a matter of fact, many Infected inhabit within the cities' slums or their underground structures, causing potential havoc to the upper class and painting the bleak theme of the world of Terra.
The existence of nomadic cities and sedentary settlement also differs from each nation and region due to cultural, economic, or geographic reasons. Due to economic inequality between cities and villages, Kazimierz seems to consist of fewer nomadic cities than most of the nations. Kjerag never intends to build even one nomadic city thanks to its mountainous topography that protects the nation from Catastrophes; on the other hand, Yan manages to build nomadic cities along valleys or even migrate an entire mountain onto mobile platforms. Despite Sargon's frequent Catastrophes, most prefer to stay in sedentary settlements. Using its southern coastline, Iberia relied on its oceanic nomadic cities during its golden age.
The nomadic city poses an intriguing question, as it is in complete defiance of the square-cube law which dictates that the volume of an object inflates exponentially proportional to its increase in surface. Most real-world cities require a lot of planning to prevent them from sinking into the earth from their sheer weight, and those are static. Just how nomadic cities manage to remain above ground while seemingly unaffected by Terra's gravity and nonetheless be capable of moving with several billion or even trillion tons of structures upon them remains unexplained. It can be inferred that the Originium reactors that power nomadic cities also provide some form of anti-gravity mechanism to counteract their colossal weight, as Originium is stated to have properties affecting the laws of physics.
- Underlined word represents the capital of the nation
- Chernobog (part of Ursus, abandoned)
- Lungmen (part of Yan but mostly autonomous)
- Wolumonde (part of Leithania, being absorbed to other regions)
- Kawalerielki (part of Kazimierz)
- "New" Siesta
- Sal Viento (part of Iberia, abandoned)
- Shangshu (part of Yan)
- Londinium (part of Victoria)
- Reefsteep (part of Sargon, abandoned)
- Lingones (part of Gaul; destroyed)
- The idea of a nomadic city is likely derived from Mortal Engines where cities were built on wheels to avoid natural disasters and political conflicts.