Trigger

A Trigger (トリガー) is a product of Neighbor technology that manipulates and is powered by trion. Despite being often used for combat purposes, Trigger technology also has other functions, and in fact it is regarded as the cornerstone of the entire Neighbor civilization. Combat-oriented Triggers have massive firepower, and are the only weapons capable of damaging and even destroying trion bodies.

Triggers can differ greatly among nations. Unlike the more powerful Black Triggers, which are created through the self-sacrifice of a particularly gifted Trigger user, normal Triggers are produced through technology. Earth developed its own Triggers after its contacts with the countries of the Neighborhood. The organization responsible for manufacturing Triggers and fighting off trespassing Neighbors is called Border.

Activation
To activate a Trigger, it is necessary to touch the Trigger Holder and give a clear signal of one's intentions to switch into a trion body. Border agents and trainees often use the vocal command "Trigger on" (トリガー), whereas Aftokrator users declare the name of the Trigger. Black Triggers have been activated both verbally and non-verbally. Border's Triggers can be switched off at any given time, usually with the command "Trigger off," but none is strictly necessary. Aftokrator soldiers do not use any vocal commands to do so. Normal Triggers can be activated by anyone, provided they have a large enough amount of trion. Most, if not all, Triggers substitute the user's body for one made out of trion, storing the original body within the Trigger Holder. Trigger Holders are sent to the same dimension as the flesh and blood body upon activation, which is located somewhere in the Neighborhood. Trion bodies grant a Trigger user an increase in strength, speed and durability. Any wound inflicted to the trion body will cause a more or less severe leak of trion, but no physical damage to the user's flesh and blood body. When too much trion is lost, or when certain parts are destroyed, the trion body disappears.

In Border
Border's Triggers are manufactured with the aim of being used by a large number of agents. For this reason, their trion consumption, and therefore their power output, are lower than those of Aftokrator Triggers. Exceptions to this rule are the special, more powerful Triggers possessed by the A-rank agents of Tamakoma Branch. Border's Trigger technology is generally considered crude by the standards of an advanced country like Aftokrator. However, soldiers from both Aftokrator and its vassal nation Galopoula have expressed admiration for their versatility, which is due to the great number and variety of Triggers in existence and the possibility of equipping and combining several of them. The engineers of Border are constantly working to improve their Triggers and create new ones, and indeed, the speed of Border's technological progress is extolled as outstanding. One of the objectives of expeditions to the Neighborhood is to secure Neighbor Trigger technology, which is chiefly done through negotiations and bargaining, but should the away agents be attacked in war zones, they will retaliate and take possessions of the Triggers of the enemy. Border is currently in possession of three Black Triggers.

Certain Triggers become available to a Border agent only when he or she has achieved a specific rank. C-rank gathers the trainees, who are not considered official agents. They are allowed to carry only one Trigger out of the ten available to them, which goes by the name of Training Trigger (トリガー). Since they are meant for training, these Triggers are not as powerful as a regular ones. B-rank and A-rank agents can equip up to eight Triggers. S-rank agents carry only one Black Trigger each, but are also allowed to carry their previous Trigger Holder.

Triggers in Border are classified according to their functions, and define the role of an agent in his or her team or on the battlefield. The main three categories are Attacker, Gunner and Sniper. They encompass the vast majority of Triggers capable of causing damage on their own. Triggers from other categories become available after reaching B-rank. Examples are Optional Triggers, Defense Triggers and Trap Triggers. Border personnel in general are given an uncategorized Trigger for self-defense (トリガー) with very low trion consumption whose sole function is to create a trion body, in the event of an encounter with Neighbors or Trion Warriors. It does not come with any sort of additional equipment.

Mechanics
In Border, the actual Trigger is installed in a chip located inside a device called Trigger Holder (トリガーホルダー), which contains eight slots that can allocate one chip, and thus one Trigger, each. Reiji Kizaki's Trigger Holder is custom-made and can allocate up to 14 chips.

Each Trigger occupies one slot in one of two columns, the Main and the Sub, each composed of four slots (seven in Kizaki's case). Main Triggers (トリガー) are automatically set to the user's dominant hand, whichever hand that is. Sub Triggers (トリガー) are automatically set to the user's non-dominant hand. Typically, the user can only activate two Triggers at a time, one from the Main and one from the Sub, with few exceptions. It is implied that switching Triggers is not as fast and/or as practical as activating a Trigger when the column (Main or Sub) is not already in use.

Each Trigger consumes a certain amount of the user's trion, even just by being equipped. As a result, each person can equip a different amount of Triggers, depending on their trion capacity. Trion value also influences the overall power of a Trigger, although the user's skill is a major factor in determining how effective it will actually be. Once a person runs out of trion, they will be unable to produce their Trigger weapon and thus be defenseless. It is however possible for an agent in a trion body to pass his or her own trion to someone else through physical contact and by establishing a "temporary Trigger link" with a specific Trigger. The Trigger remains under the control of the owner, but is alimented with the trion of the donor. However, using this feature multiple times can lead to said Trigger malfunctioning. A "temporary Trigger link" can also allow an agent in a trion body to wield a Trigger manifested by another user as if it were his or her own, without physical contact with the user or his or her consent.

Border Triggers that shoot bullets have built-in safety measures to handle strays. If someone in their flesh and blood body is hit, instead of being wounded, they will be knocked unconscious from the pain and the impact. A further safety measure makes it so that if a Trigger is deactivated in an unsafe environment, the flesh and blood body will be summoned in a location away from immediate harm.

Customization
A-rank agents have the perk of asking Engineers to customize their Triggers. In general, modified Triggers work the same as the standard model, but have added functions. Examples are: The customization privileges of A-rank agents extend to requesting the creation of whole new Triggers. At least some of these Triggers become accessible to B and even C-rank agents, as was the case for Scorpion. There are however Triggers, like Sōgetsu, which are at the very least not available to trainees. What rules govern the accessibility of Triggers developed by A-rank agents is currently unknown.
 * Ai Kitora's Scorpion. The default shape of her version has two blades instead of one and can be made to rotate around the grip much like a pinwheel.
 * Ai Kitora's Spider. It is fired through her custom-made gun, which is also equipped with a reel-in function. Although Spider is an Optional Trigger, in her case it is classified as a Gunner Trigger.
 * Yōsuke Yoneya's spear-shaped Kogetsu. Since the handle of Kogetsu requires less trion than the blade to be constructed, he requested one of the chief engineers to create a variation of that Trigger with a longer handle and shorter blade in order to allow agents with low trion capacity to have a long reach. Subsequent modifications made it possible to shorten the handle to fight in narrow spaces. It is possible it is only these latter modifications that make it count as a customized Trigger.
 * Shūji Miwa's Lead Bullet. It assigns a burden of 100kg per shot, and can be equipped in the same set of slots as the handgun, making it possible to use other Triggers while firing. Its downside is that Miwa must conjure a separate magazine which he must then slide into his firearm. The magazine is very heavy in terms of trion consumption, and the number of bullets that can be fired before reloading limited.
 * Nozomi Kako's Hound. The nature of its modification is unknown. It does not manifest as a Trion cube, but as a sphere from which smaller spheres are then emitted.
 * Yukimaru Ichijō's Thruster. Its perks are unknown. He has two of them.

B-rank agents are allowed to perform minor tweaks on their Triggers with the help of engineers. Some of them are cosmetic, others alter the functions of a Trigger slightly. Temporary cosmetic modifications can play a significant role in a fight: an example is Azuma Unit changing the color of their Bagworms to white in order to camouflage themselves in the snow setting they had selected. Permanent alterations can be used by B-rank agents and above to make a Trigger more suited to their fighting style without modifying its basic functions, which might be why they are not considered customizations. Examples of such tweaks are:
 * the Scorpion model wielded by Kazama Unit. Unlike the normal Scorpion, its default shape is double-edged, with a hollowed out, slightly longer blade. The modification allows it to stretch and contract more quickly, thus making it even more attack-oriented than the regular Scorpion.
 * Reiji Kizaki's Raygust. Its handle is shorter and more streamlined than that of the normal model, possibly in order to complement his unhortodox fighting style.
 * Yūko Kumagai's Kogetsu. Due to her often utilizing it to defend, she has requested that a tsuba be added in order to protect her hands.

Furthermore, users of Gunner Triggers tend to have different models of one same type of firearm. For example, the assault rifles of Arashiyama Unit are different from the one employed by Tatsuya Kuruma, although neither model is counted as a customization.

Standard Equipment Triggers
After activating a Trigger, the user will receive a trion body. B-rank agents and above are also endowed with additional Standard Equipment Triggers (トリガー) and accessories. Although they consume trion as a result of being equipped, and some also during use, they do not take up a Trigger slot.

Attacker Triggers
Attacker Triggers (トリガー) are modeled after edged weapons. They require close quarters combat and are extraordinarily impressive in terms of balance between trion consumption and offensive power. That is because only a small percentage of trion is required to manifest them, making it possible to devolve the rest to sheer power. In fact, Attacker Triggers are the most suitable type of Trigger for users with a low amount of trion. There are primarily, but not exclusively, three types of Attacker Triggers in Border.

Gunner Triggers
The Triggers used by Gunners and Shooters revolve around the use of bullets. Compared to Attacker Triggers, they have a lower firepower and a greater consumption of trion, but boast superior range. There are four types of basic bullets, divided in normal and special bullets. Bullets are composed of three main parts: a "body" that determines their power, a "cover" that protects it from wind resistance and extends its range, and a "propellant" that sends it forward. Trion is divided among these three components, determining the power, range and speed of the bullets. Their tripartition explains their inferiority in terms of damage to Attacker Triggers. Overall, Gunner Triggers (トリガー) are the ones that are affected the most by the amount of trion the user has. Regardless of the class of the user, all bullets are classified as Gunner Triggers, despite the Shooter class having been created first.

Gunners and Shooters fight at mid-range, most commonly as support due to their relatively low firepower. They use their Triggers tactically to control the position of the target. Each class has its own characteristics, but the fundamental difference between the two is that Gunners channel their bullets through specific firearms, whereas Shooters create trion cubes from their hands which they can successively split in smaller polygons or fire directly.

Trion Cubes
Shooters create a floating cube whose size and trion content depend on their trion reserves, and whose three basic parameters can be manipulated on the fly. This cube can be fired whole for a concentrated blast or split into smaller, identical polygons for a more varied offense. The power of the original cube is distributed equally among the fragments, whose number appears to determine their shape: the vast majority of agents splits their cube in eight, 27 or 64 parts, resulting in more cube-shaped bullets, but pyramids and tetrahedra are also possible. Shooters can control the position of each fragment at will before opening fire, increasing the spread of the volley and striking from different angles at the same time. They can further diversify their attacks by delaying some of their shots so that fragments of one same cube are fired at different intervals.

Cube fragments can remain in existence and retain their hovering abilities even if the user switches Triggers before firing them. Shooters can thus scatter bullets in specific locations, switch to another Trigger, and then switch back to the Gunner Trigger to fire the bullets they previously planted. However, they must remain within a certain distance from the planted bullets to retain the ability to control them.

Firearms
Gunners have access to an arsenal of firearms, also known as Gun Triggers (トリガー), made out of trion. Although they are classified as Triggers, only the bullets they are used in conjunction with occupy Trigger slots. At least two out of the five known types of firearm (specifically handguns and assault rifles) can be loaded with any two Gunner Triggers. When compared to the fighting style of a Shooter, these weapons are easier to operate and more accurate over longer distances, since each shot is the same as the one that preceded it. They also have an auxiliary function that increases range by an additional 20%. In addition to the three parameters of the bullets used by Shooters (power, range and muzzle velocity), firearms have three more main parameters that set them apart from one another: rate of fire, weight, and number of bullets, which determines how many rounds can be fried before a reload is necessary, as well as how much trion is allocated to each bullet. Unlike Shooters, Gunners cannot modify any of these parameters on the fly. For all these reasons, Gunners are considered more balanced but less versatile than Shooters.

Handguns and assault rifles are the most common types of firearms, but shotguns, grenade launchers and miniguns are also known to exist. Some of these weapons possess special features, such as shotguns's ability to fire multiple slugs at the same time and to adjust their spread, and possibly grenade launchers granting their discharge a parabolic trajectory. Each type of firearm presents different characteristics, but even weapons of one same type can be set with different parameters which do not count as customizations: for example, Takuma Yuba's handguns have lower range than average and can fire fewer bullets before needing to be reloaded, in return for which the power and speed of the bullets is increased; Sumiharu Inukai's firearm, which is classified as an assault rifle despite being modeled after the PDW (Personal Defense Weapon) submachine gun, is more compact and seemingly wieldier than other assault rifles; Hiro Kitazoe's assault rifle is also worthy of note, as it appears bulkier than the other models, but as a trade-off it might boast a higher rate of fire compared to other assault rifles. The fact that Jun Arashiyama's assault rifle fires small Asteroid rounds with a high rate of fire but only a single, large chunk of Meteor suggests that even different types of bullets fired with the same weapon can have different parameters. It is currently unknown to what extent the appearance and type of a firearm is a direct reflection of its parameters, as well as how much freedom the user has in modifying their parameters. Similarly, the exact mechanics of reloading have yet to be revealed.

Firearms can be made to appear immediately before use and then dispelled, although trion is expended to conjure a new one. If the user so elects, however, they can be manifested as soon as the trion body is formed and remain in existence indefinitely, even if other Triggers are in use. All-Rounders who choose the latter option can use their turned off firearms in feints at close range. Although the exact durability of a firearm is unknown, each of Yuba's bullets packs enough power to destroy one.

Composite Bullets
Any two Gunner Triggers can be combined to obtain highly destructive composite bullets, whose properties depend on those of their components. Shooters can create them on the fly by merging two trion cubes. The process requires a certain amount of time and focus, so few Shooters actually use them, but the more skilled ones can pull it off even in the heat of combat. Masterful Shooters can form a composite bullet in a mere two seconds, whereas inexperienced ones will require up to one minute. The only way for Gunners to use composite bullets is to program their weapon to shoot them; however, that weapon will be able to shoot only composite bullets. Currently, there are no known Gunners using composite bullets as ammunition. Composite bullets were invented by Kōhei Izumi.

Sniper Triggers
Sniper Triggers (トリガー) have the longest range and very high power. Unlike Gunner Triggers, Sniper Triggers are the weapons themselves, not just the bullets. A large amount of trion is used up in one shot, so they are not suitable for rapid fire. They are used almost exclusively for surprise attacks. The distance at which Snipers fight makes it next to impossible for an opponent to counterattack. However, this also means they are vulnerable at close range and require cover. Since they can eliminate the target in a single shot, Sniper Triggers are said to be capable of turning the tides of battle. Each of the three types of Sniper Triggers focuses on one of the three bullet parameters (range, speed and power). Capable Snipers change them depending on the conditions and the target. Trion is expended whenever a rifle is created.

Trap Triggers
Trap Triggers (トラップトリガー) are used to create favorable conditions for the allies of the user and unfavorable ones for the enemy by positioning hidden devices on the map and setting them off remotely.

Defense Triggers
Defense Triggers (トリガー) erect barriers to protect the user and/or his or her allies. They are considered one of the most indispensable Triggers for agents regardless of their class.

Optional Triggers
Optional Triggers (オプショントリガー) lack any offensive or defensive capabilities, but they add to the user's flexibility in combat. Their effects are extremely varied, encompassing stealth, movement, support and obstruction. Certain Optional Triggers can be used only in conjunction with a specific class or a single type of Triggers, granting them additional properties.

Exclusive Optional Triggers
Although the general rule is that no more than two Triggers – one in the Main and one in the Sub – can be in use at any given time, Exclusive Optional Triggers can be activated only when a specific Trigger from their same column is active.[BBF Q167] All known Triggers of this type are used in conjunction with Attacker Triggers.

All-Purpose Optional Triggers
All-Purpose Optional Triggers are similar to Exclusive Optional Triggers in that they cannot be used on their own, manifesting their effects only through another Trigger. However, unlike Exclusive Optional Triggers, they must be equipped in the opposite set of slots as the Triggers the user wants to combine them with, preventing any other Trigger from the same column from being activated while they are in use. All known triggers of this type can be used in conjunction with Gunner Triggers, and at least one of them can also be used by Snipers.

Tamakoma Optional Triggers
The members of Tamakoma First have each their own exclusive Optional Trigger, developed from Triggers Takumi Rindō brought back from the Neighborhood. They are completely focused on power output, disregarding flexibility and trion performance altogether. These Triggers are prototypes that do not abide by HQ regulations. As a consequence, they cannot be used in rank battles.

Unknown Optional Triggers
Optional Triggers whose functions have yet to be revealed.

In Calvaria
Calvaria is known to have few Trigger users, at least compared to Spinthir. In fact, it seems the vast majority of its military forces do not utilize Triggers, so the planet-nation relies on Trion Warriors (Mole Mods in particular) for defense. Aside from their firearms, soldiers from Calvaria also wield spears, curved daggers, swords, and staves, although these weapons may not be Triggers or, if they are, they do not generate trion bodies.

In Spinthir
Spinthir's Trigger users are easily distinguishable due to their black armor. Like the warriors from Leoforio, soldiers from Spinthir occasionally ride Trion Warriors (specifically Bamsters) in battle, although they are more frequently seen fighting on their own after breaching the enemy's defenses. This planet-nation seems to have more Trigger users than Calvaria. All of those introduced thus far dual-wielded their weapons.

In Menoeides
Extremely little is known about Triggers from Menoeides, except that their Trigger Holders are shaped like hexagonal prisms or parallepipeds, with dots and lines arranged in different motifs on at least one of the broader faces.

In Aftokrator
Aftokrator is a powerful military nation, and its Trigger technology is extremely advanced. Aftokrator engineers have developed Trion Receptors that become a part of the body of the person they are embedded in, increasing their amount of trion to create soldiers with enhanced abilities. Another impressive accomplishment is the creation of Trion Warriors with abilities mimicking those of specific Horn and even Black Triggers. Furthermore, some (though not all) of the nation's Black Triggers come with an armored cape, although it is currently unknown whether Aftokrator possesses the technology to alter Black Triggers or the Black Triggers included them from the start. Seven years prior to the invasion of Earth, Aftokrator was in possession of 13 Black Triggers.

Mechanics
In Aftokrator, each Trigger Holder seems to contain only one Trigger, aside from the equipment that comes with the trion body. The guiding concept at the heart of Aftokrator Triggers is the treatment of such weapons as an extension of one's body, which is transformed as a result. Trion Receptors prevent the trion body from being destabilized by this process. At least some of the Aftokrator Trigger Holders are worn around the wrist like bracelets.

Standard Triggers and Equipment
Trion bodies formed by Aftokrator Triggers come with different equipment from their counterparts on Earth. They are more suited for battle, but can be said to be lacking in terms of logistics, since at the time of the invasion, Aftokrator's fighters could leave the battlefield only through the wormholes created by Speiraskia and did not seem to possess Radar. Since soldiers from Galopoula, one of Aftokrator's vassal nations, were recently endowed with an emergency escape Trigger identical in principle to Bail Out, it is possible Aftokrator has developed the same technology. This is further supported by Yūma Kuga implying it is not a technology found in the Neighborhood, and by Border's Development Chief Motokichi Kinuta suggesting that it was copied from Border.

Horn Triggers
Aftokrator's primary combat Triggers are known as Horn Triggers (トリガー), as well as Enhanced or High-Powered Triggers (トリガー). Although only one of them can be wielded by each fighter, they more than make up for it with their versatility and power output. The two revealed thus far have high offensive and defensive capabilities, as well as remarkable supplementary abilities. Their raw power is so overwhelming that normal Triggers from Galopoula and Border cannot compare.

Unknown Classification Triggers/Devices
Paraphernalia created by Neighbors which do not seem to be part of standard equipment.

In Galopoula
Despite Galopoula being a small nation, its Trigger users are extolled as exceptional warriors. Their Triggers are said to be suitable for fights against multiple opponents, so it is not uncommon to see them on the battlefield even if they are outnumbered. Aside from combat, some of their Triggers are also ideal for infiltration.

Mechanics
Much like Border Triggers, Galopoula Triggers have a wide array of effects, and a single user can equip several of them. A major difference is the employment of pellets or tokens that are used up to activate certain Triggers, after which they disappear. Galopoula Triggers generally require one such token, but some may expend more or none at all. Once a token is consumed, it cannot be replaced. Each soldier can carry up to 14, stored in a holster on his or her lower back where they can be reached easily. However, if a larger supply is available, nothing prevents its usage. Galopoula Triggers can be divided in two main types: Triggers that consume a token and Triggers that don’t. The latter can be turned on and off at will, but that does not appear to be the case with the former.

Although there does not seem to be an upper limit to the number of Triggers requiring a token that can be used simultaneously, or, rather, that number corresponds to the quantity of tokens available, it is possible that Triggers of the other type follow a distinction vaguely similar to the Main-Sub binary of Border Triggers. However, it remains unclear if there is a maximum amount of them, or if they are equipped to specific body parts. The exact operating principle of tokens is also unknown. It is unconfirmed whether each of them is dedicated to a specific Trigger (Wen Sō's fear of running out of Dogs lends itself to different readings), or there is no substantial difference among them and which Trigger they activate depends on the will of the user or the circumstances.

Standard Triggers and Equipment
The basic equipment of trion bodies created by Galopoula Triggers is not much different from Border's. "Operators" from Galopoula can assist frontline soldiers with a radar-like Trigger extremely similar to the monitor of Border's Operators, but it is currently unknown if every agent is equipped with a radar Trigger per se and/or if the one used by Reghindetz is an enhanced version exclusive to him.

Named Triggers
These Triggers may be the most powerful in the arsenal of a Galopoula soldier, since each of the members of the infiltration in Border had one. At least some of them require the expenditure of one or more tokens.

Unnamed Triggers
The names of these Triggers were not revealed. Some consume tokens, others don’t. It is unknown how many, if any, of the Triggers falling in the latter category are common to all Galopoula soldiers or should be classified as standard equipment.

Unknown Classification Triggers/Devices
Paraphernalia created by Neighbors which do not seem to be part of standard equipment.

In Ergates
The Ergates Triggers revealed thus far revolve around the generation and control of Trion Warriors. The nation is in possession of at least one Black Trigger.

Triggers of Unknown Origin
Triggers whose country of origin is not known.

Trivia

 * The names of Border's Triggers can be roughly grouped in five categories: metereology, animals, foreign language words, kanji and astronomy.
 * In addition, Gunner Triggers are very often named after existing missiles, rockets or firearms.
 * Although this has never been openly stated to be a rule, the Trigger Sets of nearly all known Border agents include two Shields equipped in their Trigger Holder. Kyōsuke Karasuma and Osamu Mikumo, who have only one, are however in possession of another defense-oriented Triggers.
 * Another possibly compulsory Trigger is Bagworm, as the only four agents to lack it are the three Trappers and Asumi Amakura, whose Bagworm Tag occupies the entirety of their Sub.
 * All three known Tamakoma Triggers have been activated with the command "On" at least once, which, among Border's normal Triggers, is unique to this class.
 * Despite the vast majority of Border fighters being male, most Triggers with only one user are part of the Trigger Set of a female agent, with a ratio of 4 used by males (Full Arms, Geist, Kogetsu: Spear and the minigun) to 6 used by females (Connector, Enhanced Radar, Idaten, Makō, Sōgetsu and Timer).
 * Thus far, all trion cubes summoned by Shooters have been divided according to the principles of and have produced exclusively  bullets.
 * All of Border's prototype Triggers are Optional Triggers.
 * Much like the nations themselves, Triggers from the Neighborhood have Greek names. Additionally, such normal Triggers seem to follow specific patterns:
 * Aftokrator Triggers are named after animals.
 * Galopoula Triggers are named after titles, occupations and other terms related to women.
 * The author listed Vorvoros, Viper, Lead Bullet and Escudo as the Triggers he would like to try out, although he stated he would enjoy doing stunts in a trion body even more.