A Bounded Field (結界, Kekkai^?) is a topographic type of Magecraft that consists in knitting a network of prana and spreading it on base area, such as a piece of land or a building, to create a mystic boundary line that separates the inside from the outside. By definition, it should not be possible to move them once they are set. Those of Souren Araya are an exception. The most powerful type of Bounded Field makes the space itself act as a boundary line and it is on a level close to Magic.

Contents 1 Mechanics 2 Examples of Bounded Fields 2.1 Dead Apostle Territorial Fields (死徒領地田畑, Shito ryoudo tahata?) 2.2 Emiya Residence's Barrier (衛宮邸の結界, Emiyatei no kekkai?) 2.3 ??? ((呪層界・怨天祝祭 / 呪層界・怨天祝奉), ????)

MechanicsEdit

Once constructed, the established boundary line will delimit the range of the powers of the Bounded Field, but it is possible to engrave magic sigils across a the interior of the field to expand the area of effect and strengthen it. Removal of the sigil by a third party is possible as long as the technique used to engrave it isn’t too advanced. In this case, it is only possible to temporary hinder the Bounded Field by dissipating the prana used to activate it, but the creator of the Bounded Field can amend this by simply putting more prana back into it. In the Fate/stay night anime this was changed to the sigils being easily destroyed. However, new sigils are constructed by the actions of the old ones, making the Bounded Field capable of self-repair with due time.

As their original purpose was for the creation of safe havens, the effects that can be set within a Bounded Field are in their majority those whose aim is to protect the caster. Offensive variants do exist, but as they work through indirect magical interference their efficiency against those who can protect themselves magically is low.

Advanced Bounded Fields work on a subconscious level to prevent onlookers from noticing it, but placing those on a large area increase the chances of being detected by a trained magus. An ideal Bounded Field is the one that cannot be detected by anybody. On the other hand, a Bounded Field that can be easily noticed is seen as the mark of a third-rate magus.

Examples of Bounded FieldsEdit

• Touko Aozaki's Bounded Field
• Avalon
• Blood Fort Andromeda
• Breaker Gorgon
• Invisible Air
• Hounouden Rokujyuyonshou
• Rho Aias
• Rokudou Kyoukai
• Ryuudouji’s Barrier
• The Mist

Dead Apostle Territorial Fields (死徒領地田畑, Shito ryoudo tahata^?)Edit

Layers of Bounded Fields that the Dead Apostles use to hide their lairs, which fool even nature itself. This invisible protection, is similar to the ones that hide away the world of the fairies, it makes the lair accessible only by those who are invited in. These lairs are enshrouded by darkness, by shadows, by longing for rationally and by fear towards the taboo. Normally, the lairs of these Apostles can't be found by human beings and it takes even for the trained mages of the Mage Association several years to find one.

Emiya Residence's Barrier (衛宮邸の結界, Emiyatei no kekkai^?)Edit

A Bounded Field around Shirou Emiya's property that warns the owner of the house about individuals with malicious intentions entering its perimeter through a ringing bell. Very well made, possesses neither offensive nor defensive capabilities, but its detection powers are excellent. Unlike the one set on the Tohsaka residence, it is possible to feel a human quality from it. Constructed by Kiritsugu Emiya. However, Assasin was still able to enter the residence without being detected.

Forcefully removed by Caster in Unlimited Blade Works.

??? ((呪層界・怨天祝祭 / 呪層界・怨天祝奉), ???^?)Edit

A type of Bounded Field (translating as 'Bounded Layer') used by the playable Caster in Fate/Extra. They significantly increase the output of the next spell she uses, so presumably they are only temporary fields sustained around her person.

Magecraft
Concepts
Bounded Field • Conceptual Weapon • Gradation Air • Magic • (Second Magic • Third Magic) • Magical Spells • Marble Phantasm • Mystic Code • Mystic Eyes • Psychic • Reality Marble
Creatures
Demons • Familiar • Homunculus • Humans • Phantasmal Species • Spirits • Vampire
Holy Grail War
Command Spells • Great Grail • Heroic Spirit • Holy Grail • Master • Noble Phantasm • Servant • Servant classes • Servant Parameters
Mage's Association
Barthomeloi Lorelei • Magician • Magus • Sealing Designation
Terms
Akasha • Chants and Incantations • Elements • Gaia • Magic Circuit • Prana • Soul • Thaumaturgical Crest