World

The World (世界) is used to refer to either the Earth, Gaia, or the collective unconsciousness of mankind, Alayashiki. There also exist the Reverse Side of the World and the Outside of the World.

The Ultimate Ones are vessels upon which the planet's will is manifested, and rather than being part of the Counter Force, they are essentially the planets themselves. Unlike most other celestial bodies in the Solar System, there is no clear Ultimate One for Earth. The creature closest to being the Ultimate One of Earth is Archetype Earth.

Another definition of "world" refers to a particular location or environment, much like its real-world definition. Differing from the concept of the Earth, a world can exist in a variety of shapes, such as "the world of the humans", the "Reverse Side of the World", "mental world", or "underworld." This article will deal with the former definition of "world".

History
The Earth was initially formed from molten magma and gas. Life did not emerge until the inhospitable planet cooled and settled. The infernal landscape of the Earth before genesis has become part of the genetic memories of all creatures on Earth, and humans drew from this imagery when they created the concept of Hell.

Age of Gods
The time period beginning with the genesis of the Earth until the beginning of the Common Era around 0 AD is referred to as the Jindai (神代), during which the world followed laws based not on physics but on Mystery. This period is marked by a greater proliferation of Phantasmal Species and greater interaction between gods and mortals. This is the age of heroes and mythology, when rules of mankind and the laws of the world were different right down to the very fundamental physics of reality itself, but this period ended many years ago. Even Magecraft itself is described as being closer to Magic in this era and Caster's abilities reinforce this concept. The currently-revealed Second Age of Gods eventually transitioned into the Age of Man due to three major events.

Originally, gods existed in physical form as manifestations of nature itself, and ruled the Earth and its civilizations. The Deterioration began with the invasion of Sefar in 14,000 BC. After Sefar destroyed the majority of the Earth and a massive number of gods, she was finally beaten back by a Holy Sword forged in the core of the planet; however, due to the damage done by Sefar, the influence and power of the gods declined whereas those of humanity grew. The gods slowly began to lose their physical forms and eventually could only walk on the Earth by possessing compatible humans.
 * Deterioration

Realizing that if the weakening of the gods were to continue the Age of Gods itself would end, the gods of Mesopotamia created Gilgamesh around 2,600 BC as the keystone to connect the gods and humans. However, Gilgamesh unexpectedly rebelled against the gods and encouraged the complete separation of the gods and the humans. Due to this, the decline of the gods was accelerated and the gods lost their powers and became Divine Spirits, forced to exist in a higher dimension only able to observe the Earth without directly interfering. Later, the demise of Solomon the King of Magic accelerated the decline of Mystery.
 * Separation

On 700 BC, there was a certain Trigger that caused the end of the Age of Gods and the beginning of the Age of Man. Further details are unknown.
 * Trigger

Age of Man
Around 0 AD, the Age of Gods ended entirely and the population of humanity grew explosively. Because the Earth obeys the law of the most prosperous species on its surface, the rules of the world were completely changed from one that obeyed Mystery to one that obeyed physics. The Phantasmal Species ceded the Earth's surface to humans and moved to the Reverse Side of the World, where Mystery still thrives.

The current age is identified as the Age of Man, where Mysteries such as magecraft are dwindling in favor of science. The Five Magics were born in this age.

Counter Force
The Counter Force (抑止力) is the safety device formed by the collective unconsciousness. The concept of Counter Force is central to Nasuverse, and there are two types owned by two different Worlds: Gaia and Alaya. Gaia is the will of the Earth, the planet's intrinsic wish to survive and prosper. Alaya, on the other hand, is the collective unconsicious will of mankind to avoid extinction. As humans are creatures of Earth, Alaya was a component of Gaia. However, as mankind begins to develop independent from nature, it became independent of the Gaian system. With this divergence, Alaya is no longer aligned with Gaia and potential conflict can result.

Despite being called "the will of the planet/mankind", the Counter Forces bear no emotions. They are described as passive spirals of energy that respond to threats of planet destruction or human extinction. The Counter Forces are always active, constantly steering mankind and the planet away from potential danger. Usually, the Counter Forces act indirectly. For instance, Shiki Ryougi was driven by the Counter Force to eliminate the threat that is Souren Araya, while historically, Joan of Arc is also named as one who was empowered by the Counter Force. One exception to this is Enkidu, who is able to access the Counter Force directly through his Noble Phantasm, Enuma Elish.

Although Gaia and Alaya are intangible forces of will, each does enlist physical agents to deal with events too threatening to address with indirect intervention. The agents of Gaia consist of Spirits, Phantasmal Species, True Ancestors, and other species born from the planet. The agents of Alaya are human spirits who pledge their eternal service to Alaya in return for power during their lifetime. Agents employed in this way are referred to as Counter Guardians, and Archer is one such Counter Guardian.

There also exist unique entities known as Beasts that are employed by each World. The Beast of Gaia (ガイアの怪物) is known to be Primate Murder, but the Beast of Alaya (アラヤの怪物) has yet to be named. It is known for a fact, however, that it exists.

The Counter Forces have immense power at their disposal. However, only the appropriate amount is unleashed to address a particular event. If the threat possesses an amount of power equal to X, then the Counter Force will deploy an amount of power just enough to snuff out X and eliminate the threat. The amount of power can be as small as nudging individuals into place through "coincidences", but it can also be as great as sinking an entire continent.

According to Merlin in Garden of Avalon, Counter Force is a defensive mechanism born of the collective unconscious of mankind, and that the difference between the Heroic Spirits and the Counter Guardians of Counter Force is that the Heroic Spirits are summoned by the hopes of the men, while Counter Guardians are summoned by the despair of men.

Alaya
Alaya (アラヤ) is the collective unconsciousness of mankind, the drive for survival. Alaya constantly steers mankind away from extinction. It takes central stage in Kara no Kyoukai as the driving force leading to the event in Paradox Spiral.

Usually Alaya interferes indirectly by guiding and empowering an individual to eliminate a threat. Such individuals include Shiki Ryougi (and characters associated with her) and Joan of Arc. When indirect intervention is insufficient, Alaya will deploy the Counter Guardians. The deployment of Counter Guardians is by no means subtle, as the threat will be eliminated with the surround, inflicting much collateral damage. Touko Aozaki hinted that the sinking of was the work of Alaya.

Alaya is of particular relevance to magi, as those close to reaching the Root are deemed threatening by Alaya. Many of them go to extreme length to avoid or hide from Alaya. For instance, Araya Souren attempted to hide his approach to the Root by containing his experiment in a boundary field close to a Reality Marble, essentially masking his work by internalizing it.

Human Order (人理), also referred to as the Common Sense of Man, is the core principle on which Alaya operates for the building of the Human Order Foundation. Essentially, it is the principle that "humanity must exist for as long as possible." Parallel worlds in which humanity has destroyed itself or advanced too quickly and therefore stopped progressing are, following this principle, culled, allowing for only the most promising parallel worlds to survive in order to ensure the future of mankind.   The imposition of Quantum Time-Locks is one of the functions performed by the World.   

Gaia
Gaia (ガイア) is the planet's will to survive. Gaia protects all creatures on Earth by using Spirits and creatures of the Earth, but as mankind becomes independent, Gaia increasingly perceives humans as a source of threat due to their reckless destruction of the environment.

Gaia's response to the human threat is producing beings that can cull or rule mankind. Primate Murder was created to quickly eliminate humans. The True Ancestors are great Faeries modelled after the Crimson Moon, introduced by Gaia to rule over mankind.

The destruction of the planet by Earth-born creatures is essentially impossible due to measures already put in place by the Counter Force. Even Anti-Planet Noble Phantasms are unable to accomplish this feat.

Future
The future of the planet is undetermined, with many possible outcomes available depending on the conditions present in the parallel worlds. The Mana Depletion of the world of Fate/Extra is caused by the Aylesbury Valesti producing a pole shift that began the depletion of mana. The world of Tsuki no Sango experienced a similar pole shift and the decline of the human race rather than magecraft. The world of Notes died entirely, and humanity still occupied its corpse. Gilgamesh saw a future where, following the wishes of the Çatalhöyük, humanity outgrows the planet and reaches for the light millions of lightyears away.

Fate/Extra
The world of Fate/Extra shares the same events as that of Fate/stay night up until a certain point until a "certain major incident" in the 1970s that caused the world's mana to start drying up causes it to split off into its own separate universe. As of the 2030s, the world's mana was completely gone.

Fate/Grand Order
Due to anomalies in time, it has been shown that humans will go extinct in 2016. The future was previously established so that humans would prosper for the next century, but that future has become unobservable. Using Grand Orders, the Chaldea Security Organization plans to correct the anomalies and save the human race.

Fate/kaleid liner PRISMA☆ILLYA
The parallel world of the Ainsworth family in Fate/kaleid liner PRISMA☆ILLYA has experienced a shift in the axis of the world and the start of the depletion of its magical energy through a cause unknown to humans. This has brought on changes in the environment like abnormal weather and changes to the coastlines, such as Japan experiencing cold weather and snow during the summer. Plant life has declined, causing a decline in the animal life that feeds off the plants, and it has reached the human population as well. The process for the depletion of energy will take several hundred years, and the humans will not last more than ten generations before the world's destruction.

While science will allow humans to prevail in the short term even with the miracles of the world vanishing, the rules of the world being rewritten make it a surety that humans will perish. "Dry spots" are beginning to appear around the world in places where the energy has been completely exhausted, and an unknown particle unlike magical energy is spreading through those areas. Acting as a poison to wipe out everything alive under the current rules of the planet, the current inhabitants cannot exist in the new world. The Ainsworths plan to use the Holy Grail, Miyu Edelfelt, to use the remaining energy on the planet to make humans into beings that can survive in a new world, similar to the A-Rays and Liners of Notes.