Author's Note: This "Story" contains a rather extensive collection of Codex entries for my Vigil crossover setting (as you've likely already deduced by now). I've stated removing the Codex entries from Vigil itself to this to keep things relatively neat. As new topics come up in the Vigil storyline, I'll update this collection of supplemental data. Enjoy!

Codex: Technology/Psionics/Weapons and Armor/Ships and Vehicles

Technology: MELD

MELD is an advanced form nanotechnology designed to quickly, comprehensively, and safely alter organic bodies with new genetic traits or cybernetic implants. Canisters of these nanomachines, held in a liquid suspension, were recovered from Ethereal spacecraft and ground units over the course of the Ethereal War. The Ethereals are believed to use MELD extensively in modifying and "shaping" their servants into their current forms. The extreme versatility of MELD in altering organic bodies led to the development of both genetic modifications to integrate alien capabilities into soldiers' genomes and cybernetic augmentations that enabled troopers to operate MECs.

Study of MELD and its effects has led to the development of many cybernetic and genetic augmentations across the human species. Most human bodies are now "cleaned" of genetic diseases and can be modified for specific traits before birth, and small-scale cybernetics are commonplace. A wide range of specialized bodies, or "morphs," with specific genetic traits or augmentations are commonly used for work or recreation in a variety of environments.

While MELD's effects can be understood and the nanomachines utilized, replication of MELD has proven elusive. The complexity and power sources for the nanomachines have thus far been impossible to replicate, although study of their effects have led to less-efficient nanotech analogues being developed since the Ethereal War. A small but significant strategic supply of recovered MELD is maintained for research and experimentation purposes, under XCOM guard and administration.

Technology: MEC

The MEC (Mechanized Exoskeletal Cybersuit) is a modular humanoid heavy weapons platform designed to provide the firepower and durability of an armored fighting vehicle and the flexibility and mobility of an infantryman. The original designs were devised by XCOM during the Ethereal War as support platforms for fast-response troops. While the technology to build the exoskeleton was available, and prototype rigs were devised early on in the war, the necessary fine control over the suit to make it viable alongside infantry was a hurdle that was more difficult to surmount. Any pilot would require a direct neural link to the MEC suit to operate it as effectively as a human body, something that would only be possible with extremely experimental, costly, lengthy, and dangerous cybernetic modification.

The Ethereal substance known as MELD provided the key, enabling swift and safe modifications of volunteer troopers' bodies within days, giving them the capacity to link their limbs and brains directly to the MEC. Donning a MEC required soldiers to have their arms and limbs replaced with cybernetic links at the shoulders and hips to let them directly connect their nervous systems to the suits. This drastic surgery, however, allowed extremely effective control. MEC deployments proved brutally decisive, and the cybersuits became a pivotal component in XCOM operations.

While the supply of MELD has become increasingly more limited since the end of the war nearly two centuries ago, great advances in cybernetic augmentation and surgery have enabled MEC augmentations to become far simpler, and the advent of cortical stacks allow troopers to simply upload themselves into MEC bodies if time permits. Modern MEC designs include an arsenal of weapon designs, as well as extremely powerful kinetic barriers and armor plating. Most MEC units have specialized equipment for particular battlefield roles, such as defensive "Shogun" units with deployable shields, or "Brawler" units with close-quarters weaponry.

Because of their expense and special requirements to operate, MEC platforms are only employed by elite heavy assault or airmobile assault units. Most human militaries prefer to use MAX or REV powered armor for heavy infantry support. The sole exception is XCOM, which continues to field MEC units in substantial numbers relative to their infantry components.

Recently, both the Turian Hierarchy and Salarian Union have begun to field experimental platforms using MEC technology, while certain militias and armament corporations of the Asari Republics have been experimenting with MEC technology to find a means to use them without requiring extensive cybernetic augmentation.

Technology: Cortical Stack

The cortical stack, or simply "stack" for short, is a specialized data storage device that contains a continuously-updated digital copy of a person's memories, personality, and skills - known as an "ego." Backups are updated by nanomachines that constantly map the neurons in the brain; on average a cortical stack will be updated with a new backup over eighty-four thousand times per day. In the event of body-death, a cortical stack can be retrieved from the corpse and the backup uploaded into another brain, a process called "resleeving." The stack is normally implanted around where the spinal column meets the brain stem.

The cortical stack is primarily intended for use as an emergency measure in case of unexpected death. Creation of stored backups (in case of total loss of the body and stack) and controlled resleeving of an ego to a new body typically occurs in special "ego clinics" using devices called "ego bridges." The user lies back in a chair and rests their head in the bridge, which unfolds and molds itself around their head. Mapping nanobots similar to those used by a cortical stack scan the brain and make a digital copy which is then transferred to the target body, where more nanomachines alter the neural structure to match the previous body's. Creating a backup typically takes no more than ten minutes, which sleeving into a new body altogether can take an hour or more.

An individual resleeving often experiences "continuity stress," the disassociation between their previous body and the new one. This stress can be greatly increased by a faulty or prolonged resleeving process or - in the case of body-death - remembering one's own demise. Many people have difficulty with becoming accustomed to their bodies, particularly if it greatly differs from their original.

The technology to develop the cortical stack was developed in the wake of the Ethereal War through a study of both the advanced computers of the alien invaders and the highly-adaptive nanotechnology known as MELD. Despite initial opposition by many groups to the idea of moving egos between bodies, the promise of immortality ultimately led to widespread adoption of the technology by the time humanity encountered the geth and Citadel. Similar designs were used by the turians to transfer egos into Exo bodies and by the salarians as part of their process of consciousness transferal.

Technology: Identity Forks

"Fork" is the common terms for replicated egos that are copied into another body while the original remains active. The advent of copiable and rewritable organic and synthetic brains meant that a person could easily copy their ego to another body, assuming they could afford the other body in the first place. Forks are typically used in dangerous professions or for high-intensity multitasking, such as sending a copy of oneself to perform an errand and then return. The ego of a fork can be merged back into the original with no disassociation or complication if done so within a few hours of being created. Afterward, the differing experiences between the two egos begins to cause subtle but noticeable disassociation or "continuity stress." The greater the length of time between the fork and the original reintegrating, the more traumatic the process will become. After a certain point in time - usually more than a week - the two egos will have become such distinctly different individuals that merging can cause severe memory loss or trauma, and beyond two or more weeks the merging process can cause extreme mental disorders, including split personality disorder.

Forks are divided into three grades. Alpha forks are exact copies of the original's ego, with all of their skills and memories and personality. Beta forks typically have particular skills, personality elements, and memories, usually edited to remove sensitive data and specialized for a particular task. Delta forks are severely mentally-handicapped compared to the original ego; they are typically created either for specific, short-term tasks. They are often compared to virtual intelligences with personality imprints of the original ego, rather than fully functional individuals. A fourth type, gamma forks, are severely damaged or incomplete egos, most often the result of a faulty attempt to copy an ego or brain damage.

Legally, forks are considered a complex issue and are handled very differently depending on the jurisdiction. In some more conservative areas, some (or even all) fork variants are banned. In more permissible jurisdictions, actions taken by alpha and beta forks can be held accountable to the original ego as well, if done within a short time after splitting off. Actions taken later, once the personalities begin to diverge, can also be held accountable, but to a lesser degree. Alpha and beta forks that have existed long enough that they are significantly different from their original ego can even be considered different individuals in legal terms, depending on jurisdiction. Stored and inactive forks are considered property that can be deleted so long as they have not been active long enough to be legally divergent from the original.

Citadel law, interestingly, is more uniformly liberal than many human polities regarding forks. Alpha, beta, and delta forks are all legal in most of Citadel space. After more than two weeks without merging, or if a brain scan shows dramatic difference between the two egos, an alpha fork is considered a separate individual from the original and is afforded all of the same rights. Many alpha forks have successfully lobbied for and received asylum in Citadel space as a result.

In addition, the Geth Consensus considers all forks separate individuals from the moment they split off. Many forks that do not desire reintegration have sought asylum among the geth, although living among the geth brings about its own unique set of complications.

Technology: Ghostrider Module

Ghostrider modules are portable storage units capable of running an ego on local hardware or wetware. Effectively, they are cortical stacks that can be attached to the sensory systems and hardware of another body or synthetic. Ghostriders are typically slotted into cybernetic attachments or in protected compartments of a hardsuit or clothing. Some ghostriders are given full access to their host's onboard systems, while others are only allowed access to sensory input or local mesh and cyberware communications to talk with their host. In rare cases, egos sleeved into ghostriders can completely override their host's bodies or systems and take full control.

Technology: Morphs

"Morph" is the common term for human bodies that have been genetically modified from birth. The majority of human bodies have undergone "genefixing" processes, where the genome has been screened for hereditary diseases and had been optimized for a healthy lifespan. Many humans continue to use these baseline "spliced" bodies and apply custom genetic or cybernetic augmentations. Others are born into or sleeve into more unusual or specialized bodies.

"Menton" morphs are modified to possess greatly improved mental capacity. "Olympian" morphs with greatly improved athletic capabilities such as endurance, coordination, and cardiovascular and muscular functions. "Sylph" morphs are optimized for social situations, being modified with unusually attractive features, elimination of unpleasant body odors, and adjustment of pheromones (with specific gene-mod packages to target particular species). "Bouncers" are optimized for zero-gravity environments, with limber legs, prehensile feet, and often additional limbs for grasping.

There are also more specialized morphs, which bear little resemblance to normal human body structures, often designed for survival in extreme or inhospitable environments. A common example of this type is the "surya" morph, a massive, radiation-resistant body that closely resembles a winged whale and is designed to live and fly in dangerous environments like the upper cloud layers of gas giants or a solar magnetosphere.

Military forces, by necessity, are largely made up of normal genefixed humans, but elite formations use specialized military morphs. "Ghost" morphs are built for agility, stealth, and speed, while "fury" morphs are optimized for strength, endurance, aggressiveness, and cunning. Most military morphs use improved variants on the original genetic modifications developed from Ethereal forces, pioneered by XCOM nearly two centuries previously. Rumors of new genetic modifications taken from the various Citadel and other alien species abound.

Technology: Uplifts

Uplifts are animals that have been granted increased intelligence by genetic and physical modification, often making them comparable to humans, as well as granting them the physical capacity to converse with and become part of human society. In modern society, uplifts are relatively common sights, although some species are much rarer than others. The majority of uplifts are descendants of animals that already possessed substantial intelligence: primates, avians, cetaceans, suidae, pachyderms, and octopi are the most commonly-encountered variants. More recent developments have allowed other types of uplifts, including ursine, feline, lupine, and mustelidae uplifts.

Much of the uplifting process involves not simply increasing cognitive capacity but modifying natural instincts and social structures to enable the uplift to properly survive in human society. In addition, most uplift bodies had to be significantly altered to allow them to function in human society, particularly with regards to giving them manipulators. Most uplift bodies are so significantly removed from the original species that they are designated a completely new species.

Uplifts previously faced severe legal restrictions when they were first developed in the 21st century, following the Ethereal War. Initial uplifts were considered property of the corporations and governments that created them, while social movements and aggressive lobbying by human and uplift-rights organizations eventually earned most uplifts their freedom. Even after gaining rights and recognition in many jurisdictions, uplifts faced issues with the genetic coding and structures used to create them being patented by their parent corporations, rendering them legally unable to reproduce without the corporation's permission. After significant lobbying and legal battles, including surprisingly intense pressure from Citadel interest groups in the 22nd century, the majority of uplift gene-coding was released and uplifts are now legally able to reproduce.

Some jurisdictions still pass restrictive laws on uplift creation, particularly the Jovian Republics, and uplifts are often restricted or banned from more bio-conservative colonies and habitats. By contrast, the Citadel has broadly extended legal protections and asylum to uplifts. In addition, the various Citadel species have also been experimenting with the uplifting process, particularly with varren, although without MELD-derived gene-modification these experiments proved significantly more challenging prior to contact with humanity.

Technology: Puppet Sock

Originally developed as a device to control a criminal population in maximum security prisons, puppet socks are neural implants that allow an authorized "puppeteer" to remotely control an organic's body, either through an uploaded mind or fork in a ghostrider module or remote control via radio, mesh, laser, or other communication device. humane" variants of puppet sock technology automatically render their "puppet" unconscious when activated, allowing the remote operator to move their puppet to a secure location. Cheaper or simply more cruel puppet socks allow their puppets full sensory input while the puppeteer controls their bodies.

Puppet sock technology is tightly regulated in Citadel space, and only authorized agencies are allowed to use them. Extensive paperwork and very strict medical examination is required before the device can be installed, and they are rarely implanted in fully self-aware beings outside of prisons except in specific cases such as individuals with uncontrollable mental ailments that could render them a danger to themselves or their surroundings. Organic weapons systems such as Replica soldiers are also outfitted with puppet socks to allow them to be remote controlled by a central commander in situations where normal control methods such as voice operation are unavailable.

Technology: Wormholes

Wormholes are point-to-point gateways between two locations in space, opened through the use of either psionic humans with Spatial talent, or through the use of Durand-Vahlen Spatial Transition drives with a psychic operator. Opening a wormhole requires targeting both points and linking them together using psionic energy. Because objects in space are always in motion, precise targeting data is necessary to open wormholes with any accuracy at beyond light-second ranges. This is typically achieved using either drones transmitting through local comm buoys or with hyperwave scanners.

Wormholes end to be short-lived and unstable, requiring great concentration from the psionic operating them. In addition, opening wormholes within the gravity well of a planet is extremely difficult, due to the interference from atmosphere, gravity, and the magnetosphere. Moving from an orbital environment to a gravity well is often violently destructive. Spatial psionics are capable of generating point-to-point wormholes in-atmosphere, but these points need to be "anchored" to physical objects, with the most common targets being walls. Recent developments of man-portable DV "phase" systems by Armacham Technology Corporation resulted in more stable, long-lived wormholes, and have seen employment both in combat and emergency-rescue scenarios.

Ethereal use of wormholes appears to be significantly more sophisticated than current human understanding. The Temple Ship was able to easily transition into Earth's atmosphere with no ill effects beyond causing major gravitic distortions, and intraship teleportation with wormholes was observed by XCOM troops boarding the Temple Ship. It is also theorized that wormhole generation was the means by which the Ethereals were able to easily move their craft into Earth's atmosphere without being detected by satellites or ground sensors. Little of the technology that the Ethereals used for these operations was recovered, leading to mostly speculation on their methods.

Technology: Wormhole Arrays

Wormhole arrays are specialized Durand-Vahlen Spatial Transition drives built in conjunction with mass relays, designed to allow movement between secondary relays that normally cannot connect. The array takes the form of a latticework surrounding the "launch" end of a mass relay, with several DV drives operating in conjunction. The lattice is sufficiently far enough from the relay that ships transitioning normally will have already entered the normal mass-free corridor that forms between the relays before it would otherwise hit the lattice.

When the array is in use, it will generate a specially-calibrated wormhole that opens between the entry point and the target relay, which will have its own lattice. When a ship approaches the relay and transmits its mass and destination, it will do the same to the wormhole array, transmitting its actual destination. Upon the relay's normal activation, the wormhole opens, "catching" the outgoing ship and the mass-free corridor it is using and redirecting it to the target relay. The target does not need to have an active or even intact array to receive the transitioning ship, but the vessel will be stranded at the destination without another array, unless it takes other relays to return to its launch point.

There are relatively few working links between different relays, as experimentation with probes often ends up sending them into deep space. If a link between two relays is successful, a construction ship is sent through to the target relay to build a new array. Transitions through wormhole arrays can be mentally disturbing and often cause feelings of nausea and discomfort. In addition, there is a size limitation to the ships that can be sent through; any ship larger than the wormhole created by the array will be shorn apart, with the portions not fitting into the wormhole being sent to the relay's original destination.

Armacham Technology Corporation maintains the rights to the proprietary technology used in the wormhole arrays, although the designs are accessible to government agencies, particularly XCOM, which requires a PsiCorps presence on each lattice because of their use of psionics.

Technology: Mesh

The "mesh" is the current outgrowth of the former internet, a massive decentralized array of wireless electronic devices, radio transmitters, and sensor networks, all in constant communication. The vast majority of the transmitters and network connections are so unobtrusive that they are typically built into any device or object that could conceivably need to communicate, resulting in an endless array of thousands or millions of nodes. Once an individual has entered a habitat or colony, they are usually automatically connected to the mesh and everyone in the immediate area.

Meshes are difficult to lock down or disable, because of their decentralized nature. Individuals moving through an environment with a mesh system are easily trackable without particular security countermeasures to hide their presence. Infomorphs and virtual/artificial intelligences can easily track all movement within a mesh system and maintain constant communications.

The mesh is used not only to maintain constant contact with local networks but also for emergency and security reasons; if there is a danger, nearly everyone in the environment is made instantly aware via emergency alerts. However, despite the mesh's prevalence, basic security procedure is typically observed. Critical electronic systems such as weapons, life support, and power controls are isolated completely from the mesh and require physical access.

Technology: Vahlenite Composite Alloy

The composite alloy used in all Ethereal manufacturing, "vahlenite" - named after XCOM's lead researcher during the Ethereal War - is an exceptionally light and durable metal with exceptional tensile strength. Manufacturing this alloy only became possible after many years of reverse-engineering. Craft and armor constructed from this alloy typically remained intact even after severely damaging collisions or bombardment.

Compared with alloys produced by Citadel metallurgy, vahlenite is only marginally stronger and more durable. However, it possesses uniquely effective heat-absorption capabilities and a tremendously high melting point, rendering it particularly effective against thermal-based weapons systems such as plasma or lasers. Geth-derived vahlenite proved even more resistant to heat, and when used in conjunction with kinetic barriers, rendered warships virtually immune to plasma weaponry and made surface-based units exceptionally durable against plasma bombardment.

Vahlenite projectiles, used in alloy penetrators and mass accelerators, have become increasingly popular in armor-piercing ammunition due to their ability to penetrate armor and synthetic bodies without deforming.

Vahlenite is in high demand for any materials or equipment that will be exposed to high temperatures. Reactor and heat shielding, starship construction, and specialized equipment operating on high-temperature or high-pressure environments are common applications for vahlenite alloys. Vahlenite is notably more expensive to use compared with more established and cheaper Citadel-developed alloys and composites.

Technology: Gollop Device

The Gollop Device, or "Psi-Link" was a device used to tap into the psionic communications network used by the Ethereals. Using the Gollop Device enabled Colonel Annette Durand to directly link her mind into the alien network, simultaneously allowing her to converse with the leader of the Ethereals attacking Earth and amplify her own powers. This has come to be referred to as a "Synchronicity Event."

The original device remains under secure lockdown by XCOM, and attempts to build copies to tap into the alien communications have been largely unsuccessful. Rumors persist that variations have been built that amplify natural psionic abilities - similar to what occurred when Colonel Durand tapped into the Ethereals' collective network. However, should such devices exist, they are likely a severe security risk, as any such device would have the potential to communicate with the Ethereals.

Another persistent theory, based largely on Durand's own accounts after using the device, is that the Gollop machine allows communication with psionic entities beyond the Ethereals. As no one else has been able to tap into the network with a working device since then, this theory remains untested.

Technology: Replica

Replica are vat-grown clones designed to serve as disposable shock troops, developed by Armacham Technology Corporation. Replica are given extensive military training, both during their six month growth cycle and for two years after being "born" before they are officially released on the market. A typical Replica soldier is capable in nearly all light infantry roles, and specialized units are trained as REV/MAX operators, pilots, reconnaissance, and other roles. When not engaged in combat operations, Replica are usually stored in stasis pods that automatically maintain nutrition and other bodily maintenance. The average Replica's lifespan is ten to twenty years, depending on version number, although actual life expectancy is far lower.

Replica have specially-edited personalities that are focused entirely on combat and military matters. While Replica are allowed great flexibility in completing objectives, they are not mentally capable of disobeying orders. For this reason, they are ill-suited for occupation or peacekeeping operations, and Armacham has received some media flak due to several instances of clients using Replica soldiers to commit war crimes that normal troops would balk at.

Most Replica versions are based around particular individuals' experiences and skills, although severely edited to keep them compliant. While they have been observed to express fear, anger, or disbelief, Replica almost always maintain discipline and typically do not break or retreat in combat unless ordered, even when facing overwhelming force.

Replica soldiers are normally voice-controlled from designated "officers" which are usually other Relica who have been assigned command duties. The universal training of Replica units and preset chains of command allow for immediate and smooth transitions between commanding officers to adapt to changing battlefield conditions. Experiments to create Replica that communicate electronically or even with psionics have occurred, with the Strategic Defense Coalition particularly interested with the possibility of a psionic commander able to control Replica forces on a continental or global scale.

Because of their low cost, flexible skillsets, lack of moral compunctions, and high discipline, Replica soldiers are in high demand. The most frequent purchasers of Replica units are Terminus warlords and mercenary groups that require disposable shock troops. Another large purchaser is the New Conglomerate Security Command, which has more than twenty percent of its naval and ground combat elements made up of Replica units.

Technology: Hyperwave

Hyperwaves are a transdimensional communication and sensory wavelength that operates in a similar manner to wormholes. Ethereal ships rely heavily on hyperwaves for communications, and most modern human warships mount a hyperwave communicator, as well as a hyperwave scanning system that allows for remote FTL observation of a limited area within a star system. Despite their range, hyperwaves are limited in the area that they can cover; passive and active conventional scanners can observe an entire star system at once, but are limited to lightspeed signals. Unlike many Ethereal technologies, however, hyperwaves do not require a psionic operator to use, and as such are becoming very common in Citadel and Terminus space.

Despite the near-instantaneous speed of propagation, hyperwave communication has a limited effective range; a transmitter typically can send a message anywhere within a star system but not beyond. For this reason, intersystem communications still remain dependent on comm buoys. Warships typically use hyperwaves to coordinate tactical fleet movements within a system.

Hyperwave transmissions are still limited by current bandwidth. While able to instantly send signals across a star system, large data packets still require time to download or upload.

Hyperwaves have difficulty observing into a planet's magnetic field unless they are already stationed on the planet itself. Thus, they can observe fleets in orbit from the edge of a system, but cannot accurately see what is inside a planet's atmosphere.

Technology: Elerium

Elerium is a psionically-generated material that releases enormous amounts of energy when bombarded by accelerated particles. Elerium proved to be a vital component in Ethereal technology, providing their craft and weapons with the enormous amount of energy needed to keep them operational. Subsequent research and development into the element showed that it was not naturally occurring, requiring concentrated effort by an Energy psionic on a specific composition of elements to slowly convert it into elerium.

While elerium produces enormous amounts of energy, it has a significant half-life when it is being bombarded, causing existing stocks to constantly fade without constant replenishment. As a result, elerium is typically relegated to high-priority facilities, crucial research projects, and elite military units that require the sheer power it yields. The advent of helium-3 as a stable fuel source in fusion reactors led to it being adopted as the primary fuel source for the majority of humanity.

Psionics

An ability identified in the human (and later, asari) species to alter their environment or their own physical bodies using an as-yet-unidentified power source, referred to among humans as "the Gift." Psionics is a natural component of the asari, coupled with their biotics, but manifests in various degrees in humans. Psychic power - technically referred to in research documentation as "telesthetic capability" - requires a great deal of concentration from the user to generate active effects, although some effects, such as empathic detection of thoughts and emotions, can occur passively.

Psychic power is directly tied to the Gifted individual's nervous system. When their abilities are activated, increased electrical activity occurs throughout the body, and psychic energy flows through the nervous systems, particularly along the spinal column and through the brain. It is theorized that the element zero nodules that form in biotics' bodies somehow interfere with this function. To date, no children who have survived prenatal exposure to element zero have ever developed psychic ability, even those who are directly descended from psychics.

Asari use psionics in conjunction with biotics for finely-tuned manipulation of dark energy fields and gravity. In addition, psionics are integral to the "melding" process that allows for connections of nervous systems and asari reproduction. The revelation of psionics as a component of their biology has caused significant social and individual consternation among the asari, but has not fundamentally altered their society. Most asari treat the revelation to simply be a discovery of and enrichment of their own powers.

Most psionic talents and disciplines are naturally born, but can raise their capacity through continuous training. High-stress situations such as combat or disasters can trigger "amplification events" that dramatically boost psionic power. Many children manifesting psionic abilities can have a "nova event," which is an uncontrolled amplification event that can cause significant destruction. This is one of the reasons why XCOM's PsiCorps insists that children undergo regular screening for the Gift and why any child manifesting psychic ability is required to be registered and taken for training immediately.

Psionics: Classifications

Human psionics are divided into five broad "disciplines."

Energy involves the manipulation of thermal, electromagnetic, or kinetic energy in the surrounding environment. Most commonly this takes the form of telekinesis, including manipulating objects or creating defensive barriers.

Internal uses psionic energy to enhance the physical body, altering aspects such as strength, speed, mental capacity, reaction times, and healing rate. Stronger psychics capable of this discipline are able to achieve superhuman feats of strength or speed.

Mental involves the use of psionics to strengthen or affect the minds of others, as well as detecting other minds or resisting external mental influence. Subsets of this discipline involve telepathic communications and detecting movement or changes in the nearby environment.

Spatial involves control of the locations and spatial relations of objects, allowing for one to create gateways between objects, wormholes in zero gravity environments, or short-range teleportation.

Manifestation involves use of psionics to generate physical or insubstantial projections of objects, creatures or entire environments.

Psionic disciplines are identified using a complex ranking system to identify individual disciplines, subdivisions, and power levels within each division. This has been reduced to a common shorthand of Discipline: Numerical Ranking, followed by (Subdivisions: Numerical Rankings). For example, Energy 4 (Thermal 5, Kinetic 3).

Psychic individuals as a whole are ranked by a tier system, running from D-tier (the lowest, with barely above-baseline human capacity) to A-tier (highest-tier, generally having the capacity to cause widespread destruction). A-tier psychics are exceedingly rare, with less than a dozen having ever been recorded in human history. The vast majority of human psychics are D and C-tiers.

Psionics: Life as a Psionic

Psionics, like biotics, wield great power but also face a number of inconveniences. Much like biotics, Gifted individuals consume greater amounts of calories while using their powers and develop consequently ravenous appetites. The typical combat ration for a human soldier is around three thousand calories (up to four thousand for olympian, ghost, or fury morphs), while both biotics and psionics receive roughly five thousand calorie rations. In addition, most carry energy drinks in case they need to quickly restore lost calories in action.

Psychics sometimes experience feedback from others in proximity. Strong or uncontrolled Empath effects can generate unexpected hallucinations. Particularly strong psychics can intentionally or unintentionally generate shared "mindspace" hallucinations with another who bears the Gift. Very strong psychics can sometimes affect Gifted on the other side of planets or in orbit.

Because of the danger of their abilities running haywire, most Gifted wear emergency psi-shielding to mitigate uncontrolled effects. In rare cases, psychic abilities can cause interference with element zero cores. As a result, Gifted must be careful when using craft and machines that run on element zero, and usually try to stay away from active mass effect cores that are not equipped with psi-shielding.

Psionics: Society

Psychic abilities, particularly Empaths' ability to read emotions and surface thoughts, has led to mistrust and suspicion in many humans. Popular misconceptions about biotics having similar abilities has resulted in the same distrust bleeding over onto biotics as well. People who are religiously, philosophically, or ethically opposed to cybernetic and genetic modification view psychics and biotics as symbolic of the dangerous directions that they believe humanity is heading toward. In certain bioconservative colonies or habitats, particularly in the Jovian Republics, both biotics and psionics are only permitted entry with an armed escort.

Fear and suspicion toward psychics are only amplified by the tendency for psychic abilities to violently manifest in children. Children are usually tested once a year until they reach adulthood to determine if they have the Gift, and children that show positive for psychic ability are taken in for training and education by XCOM's Psionic Corps. Many parents skip the testing process out of mistrust, misunderstanding, or fear, and other colonies simply do not have the facilities to regularly test all children. In addition, unexpected manifestations can occur, especially in high-stress situations. The fact these events are usually followed by XCOM PsiCorps teams' arrival tends to exacerbate the mistrust.

Mistrust and fear of psychics also exists among aliens, and in many places is just as intense as it is among human bioconservatives, particularly among the turians (who also extend their mistrust and suspicion to biotics as well). Psychics outside of human space, particularly B and A-tiers, are often offered (or in the case of military psychics, required to have) an armed escort, and are usually followed by discreet surveillance teams to keep them safe. On the Citadel, psychics receive an additional C-Sec escort, and local governments on colonies will often provide a protective detail.

Despite social stigma from bioconservative circles, psionics are highly valued for the utility of their powers. Police, emergency rescue, and military forces offer enormous incentives for psychics to work for them, and PsiCorps works diligently to train them for both civilian and military career paths.

Due in part to the social stigma that both face, psionics tend to find common cause and friendship with biotics. Many human psychics find themselves gravitating toward asari colonies and habitats, as the asari are much more tolerant of both other species and fellow biotics and psychics. A not-insignificant number of psychics have also found their way into geth territory.

Psionics: Psi-Shielding

Fundamental defensive devices against psionic attack were developed late in the Ethereal War using cybernetic implants recovered from Ethereal bodies. These implants were determined to generate a particular low-powered signal that interfered with incoming psionic energy, effectively forming a sort of "white noise" that disrupted psychic power. Properly attuned to their wearer, these devices could protect against enemy psychic attack while allowing the wearer to project their own power.

Initially incorporated in "mind-shields" that protected XCOM soldiers from psychic attack, these shielding devices became more widely used for containing psionic criminals or psychics with uncontrolled abilities, such as children whose powers recently manifested. Properly constructed and supplied with power, large psionic shielding systems could potentially contain even an uncontrolled A-tier psionic or an Ethereal.

A modern outgrowth of psi-shielding is the "psi-weave," a thin layer of shielding woven into clothing, hats, and uniforms to interfere with external attack (assuming one is paranoid or wealthy enough to pay the price). Thicker and more powerful psi-weave is worked into specialized armor or full-body cloaks or coats. These "psi-cloaks" are common issue among XCOM Sentinels or other law enforcement who expect to face psychics, and are coupled with shielding in armor and helmets to give them a decisive edge when confronting psionic criminals.

Psionics: Nova and Amplification

Improperly trained or inexperienced psychics have difficulty controlling their powers. Many psychics have described their powers "running away" and being unable to stop the energy they have access to, particularly in high-stress situations. These are colloquially referred to as "nova" events. Psychics who "go nova" are often either children whose abilities manifest unexpectedly, or inexperienced psychics who are still learning to control their powers. Nova events tend to be extremely violent, particularly if the psychic has Energy, Spatial, or Manifestation capabilities.

More uncommonly, trained psychics may experience nova events if their are channeling too much power, especially in dangerous scenarios such as combat or ongoing disasters. Unlike inexperienced individuals, however, a properly trained psychic can at least partially control the explosive discharge of energy, directing it safely away from bystanders and allies, or in rare cases even directing it at an enemy.

Amplification events are similar to nova events, but involve an abrupt and unexpected increase in the ability to channel energy. Most often these events are accidental, such as when a psychic is controlling a great deal of energy in difficult or stressful circumstances. Because of the abrupt increase of power, amplification events can lead to a psychic going nova.

Because amplification events can greatly increase their power, some weaker psychics deliberately attempt to invoke them through aggressive training, channelling power, and putting themselves in life-or-death situations - which often result in injury or death. Only one known instance of deliberate amplification is known: Colonel Annette Durand's interfacing with an Ethereal-built Gollop device. Other attempts to force amplification through deliberate stress and exposure to danger have largely resulted in failure, although it is theorized that if a psychic were to interface with another Gollop device, they would become much more powerful.

Weapons and Armor

Weapons: Plasma Weaponry

Plasma armaments expose gases to an extremely strong electromagnetic field via lasers, which results in a positive or negative electrically-charged plasma. These high-energy plasmas are then propelled by shaped electromagnetic fields at a target, transferring intense thermal energy to the target. The beams or bolts are often hot enough to char or incinerate exposed flesh and melt or vaporize many inorganic materials.

Energy requirements to generate and shape the plasma are enormous; Ethereal-derived plasma armaments require elerium cells to manage the energy requirements, while turian-designed fusion rifles use sealed hydrogen-oxygen fuel cells. The energy requirements make such weaponry prohibitively expensive, and the raw price renders them unfeasible for arming large numbers of soldiers.

Despite their raw destructive power, plasma weapons have certain limitations. Contrary to popular belief, plasma armaments are not directed energy weapons like lasers. The charged atoms possess mass and therefore can be deflected by kinetic barriers. The low mass and kinetic energy of plasma means that even relatively weak kinetic barriers such as atmospheric containment systems can stop plasma fire. However, the heat from the plasma will continue ti bleed through the barriers, especially within an atmosphere.

The lack of specialized ammunition makes them inflexible, particularly against targets specifically hardened against plasma. Targets defended by heat-resistant vahlenite plating and kinetic barriers can withstand significant plasma bombardment, with the kinetic barriers halting the charged high-energy atoms and the vahlenite absorbing the radiating heat. as a result, plasma weaponry are largely ineffective in space combat so long as shields remain intact, although once shields are disabled plasma can swiftly destroy the target.

Weapons: Alloy Penetrator

Initially developed toward the end of the Ethereal War, alloy cannons were designed to launch spikes of vahlenite in tightly-grouped packs akin to shotgun pellets. Many initial designs proved ineffective because the alloy projectiles would destroy the barrels of the weapons while firing. Because of the extreme durability of the vahlenite projectiles and high energy availability of elerium power cells, the projectiles could be fired at extreme velocities, allowing them to penetrate nearly any known infantry-scale armor at the time. Upper-end velocities could potentially penetrate tank armor with sheer kinetic energy without seriously deforming, although recoil rendered such weapons unfeasible even for augmented humans.

Modern alloy penetrators use a single long vahlenite projectile, with mass effect fields to accelerate the spike to extreme speeds. The majority of the weapon's bulk is used house recoil-absorption systems and the power generators to accelerate the projectile. Even at low power, such weapons impact hard enough to pierce most modern infantry armor. Higher power settings can launch a humanoid target and pin them to nearby objects. At maximum power the weapon can mission-kill infantry fighting vehicles, heavy mechs, and MEC units, although these settings demand substantial augmentations, a synthetic body, or a particularly large and durable uplift with powered armor to use without pulverizing limbs.

Weapons: Lasers

XCOM-derived laser weapons remain one of the most commonly-employed weapons in the galaxy, due to their ability to completely ignore kinetic barriers. Prior to the study of Ethereal power systems, man-portable laser weapons were largely impractical. Modern laser weapons are commonly-issued among human and Citadel military forces, and are nearly as readily-available as mass accelerators, although more expensive due to requiring much greater power to operate..

While lasers are able to bypass kinetic barriers, most modern armors have been adapted to compensate. Vahlenite plating, reflective coating, and ablative armor systems are common defenses. It is not uncommon for military personnel to carry both laser and kinetic weapons, usually having one as an underbarrel mount, to deal with particular defenses.

The Citadel was extremely quick to adapt human laser technology into their GARDIAN systems. As a result, the effective range of GARDIAN point defense has increased by an order of magnitude.

Weapons: Particle Cannon

Particle accelerator weapons accelerate atomic particles at extremely high speeds at a target. Much like plasma weaponry, particle beams are shaped by electromagnetic fields, and electrostatic "lenses" are used to focus the beam for destructive effect. Particle cannons proved to be highly effective in the Ethereal War, but were so large and heavy that they required MEC units to operate, and were exceedingly expensive; a single MEC particle cannon could cost more than an entire Raven jet interceptor and its associated maintenance costs for a full year.

Modern particle cannons are less expensive but are still special-issue equipment due to prohibitive costs, requiring sizeable amounts of elerium to power them. Experiments with starship-scale particle weapons have shown great promise, but power generation systems necessary to make them effective have not yet been developed without increasing ship tonnage to an unfeasible degree. As one engineer explained, "You can have a warship, or a particle cannon with engines."

Like plasma weaponry, the beam fired by a particle cannon uses charged atoms, which possess mass, and are therefore affected by kinetic barriers. Because of the extreme speed and charged nature of the particles, at least some of the beam will be able to penetrate the kinetic barrier, although with greatly reduced energy. A well-placed particle beam can mission-kill an enemy soldier, mech, or vehicle if aimed at a vulnerable point.

Weapons: High-frequency Blade

High-frequency blades (or "HF" for short) are weapons that use high-powered alternating currents that cause the weapon to resonate at extremely high frequencies. Materials struck by the weapon while it is active experience a disruption in molecular bonds similar to being subjected to a biotic warping field. This allows an HF blade to cut through armor and machinery that would be totally immune to conventional melee armaments. In the hands of an augmented human, synthetic, or combat morph, an HF weapon can slice through even tank-grade armor plating. Because of the molecule-disrupting nature of the blade, simply making contact with the edge while the weapon is active can cause serious damage. The alternating current generates a visible "sparking" electrical effect that makes the weapon's nature obvious once activated.

HF weapons have some limitations. Beyond the obvious - that the user must be in extreme close range - if the blade makes contact with another object with similar alternating currents, the two will cancel each other out briefly. Explosive reactive armor can also detonate to repel the blade before it can slice into vital systems or flesh. The Foucault-current effect generated by "fortification" armor modules can also resist the edge of an HF blade more effectively than standard armor. The warping effects from tech armor shields also detonate when they come into contact with the alternate current of the blade. Finally, hardened kinetic barriers programmed to repel all matter, such as omnitool shields or geth "hex-shields," completely ignore the molecule-disrupting effect of the blade, although they still drain power when struck by the blade itself.

Attempts to reduce HF blades' properties down to projectile size have proven difficult. The equipment needed to run the alternating current is too large and expensive to fit into most bullets.

Knife-sized HF blades are a common sidearm for many soldiers. Larger and heavier weapons are often carried by elite units who may face extreme short-range combat such as during structural assaults or boarding actions. They are also common tools among engineering units and emergency rescue personnel due to their ability to cut through obstacles. On worlds or habitats with restrive weapon laws, low-powered, concealable HF weapons often bypass firearms restrictions.

It is rare to see professional military personnel carrying full-length HF weapons due to their bulk. However, as one turian veteran explained, "You see someone with a big HF blade, you pay attention. Either he knows what he's doing, and he's dangerous, or he's a colossal idiot, which makes him really dangerous."

Weapons: Fusion Rifle

Contact with humanity presented the Citadel with a previously-unseen set of technologies, including practical, humanoid-portable energy weaponry. While the Citadel was quick to adopt laser weaponry, they found a significant difficulty in adapting plasma weapons due to their reliance on elerium, a material that could only be produced in limited amounts by human psionics. Asari attempts at mimicking human methods proved ineffective, and existing power generation technology could not produce the enormous energy requirements needed to make man-portable plasma weapons viable.

The Turian Hierarchy, working with human engineers, was able to develop a workaround to the elerium limitation using high-capacity sealed hydrogen power cells. The subsequent system lacked the long-range coherence of an elerium-based plasma weapon, and required half a second to fully charge before firing, but could still produce a large, devastating burst of high-energy plasma that proved even more destructive at short range than an elerium-fueled weapon, and also in a much more compact package.

These "fusion rifles" have proven extremely popular as alternative close-quarters weapons, and have found extensive use alongside alloy-penetrators and shotguns in armories across the galaxy. Despite their limited magazine capacity - usually only able to fire three to five shots before reloading - fusion rifles have become the weapon of choice for soldiers and mercenaries expecting close combat with augmented opponents, synthetics, and krogan.

Armor: MAX/REV Powered Armor

MAX (Mechanical Armored Exoskeleton) suits are an offshoot of MEC technology, adopted by many military forces toward the end of the Ethereal War. MAX units are heavily-armored powered exoskeletons that can mount heavy weapons and provide supporting infantry fire at a greatly reduced cost compared to MECs. The improved armor and weapon capacity comes at a marginal mobility reduction compared to lighter-armored humans in standard carapace or artificial-muscle suits, although this is mitigated by element zero cores to reduce mass and improve movement. Compared with MECs, however, MAXes are smaller, lighter, less agile, and less heavily-armed.

MAX suits have been described as "the Kalashnikov of powered armor" due to their low price and ease of operation. Any soldier trained in the use of a MAX can quickly enter the armor and pilot it without needing to take the time to sleeve into a specialized MEC body, allowing a much larger pool of potential operators. In addition, most MAX designs are robust and simple enough that soldiers can operate them with minimal training, although maintenance requires more specialized skills. The lower price, ease of use, and lack of requirement for specialized bodies and augmentations lead to nearly all modern militaries adopting them for regular use as infantry support weapons.

In more recent times, REV (Reactive Exoframe Vehicles) have been developed as a middle ground between infantry fighting vehicles, the mobility of a MEC, and the ease of use of a MAX. Heavy suits of armor that fully encase the operator, REV suits handle more like armored vehicles than powered armor. Their size and bulk enable them to mount stronger kinetic barrier generators and comparable weaponry to a MAX, as well as a more sophisticated onboard virtual intelligence system to manage to much more complex operational requirements of the suit. The virtual intelligence also allows a REV operator to move with greater agility compared to a MAX, and operators do not require specialized augmentations or resleeving to operate them.

These benefits come at the cost of much greater expense - a REV platform can cost as much as several MAX suits - as well as reduced utility in difficult terrain due to increased mass. As a result, REV platforms are assigned to specialist combat such as zero-gravity assault teams and airmobile quick-reaction forces which can take advantage of their firepower and heavier armor.

Ships and Vehicles

Ships and Vehicles: Combat Drones

Drone systems are used extensively by human militaries and civilians. Most military drones are outfitted with cyberbrains that are capable of supporting neuro-modeled artificial intelligences similar to human minds. Drone systems are able to communicate and network with humans to coordinate their actions intelligently. Most drone variants have backups so that their experiences can be recorded and shared in case of the destruction of their current bodies.

Several drone types are based off Ethereal models and synthetic designs. HULU drones are based off Seeker designs, and are optimized for reconnaissance work, using optical camouflage and their ability to fly and maneuver through tight spaces to observe their environment. ODIN drones are based off Cyberdiscs, and are designed to serve as mobile weapon support platforms. FENRIR drones are based off early lupus uplift experiments, with their neuro-artificial intelligence based off stable but non-self-aware uplifted wolves. These drones specialize in recon-in-force and close-range assaults. GRENDEL heavy assault walkers serve as armored tanks in dfficult terrain, with fundamental deisgn elements taken from Sectopod engineering.

Because of the relative durability of their frames and the lack of congitive disassociation they experience upon death, drones are typically used as the "mechanized speartip" of any assault, including "smashdown" orbit-to-surface drop pod assaults.

While drones are non-sapient, they skirt close to full AI status. Some specialized models have been built with advanced neuro-AI cyberbrains that match human intellects. Other experimentation involves integrating geth-style processing-sharing and communication functions to improve in-field performance.

Ships and Vehicles: Beowulf IFV

The Beowulf is a modular XCOM-issue infantry fighting vehicle notable for its ability to quickly adjust loadouts to handle any task - an important design requirement, considering that XCOM can face any kind of threat in nearly any environment.

The standard Beowulf configuration features a fully NBC sealed compartment with room for eight passengers and both a gunner and driver, although these positions can be taken over by infomorphs if needed. In IFV configuration, the Beowulf mounts a standard set of weapons: anti-armor alloy penetrator, rapid-fire laser cannon, and a heavy plasma cannon. Should the situation demand it, the Beowulf may also fit heavier armaments, including a multiple rocket launch system, plasma and kinetic mortars, anti-air missiles or cannons, engineering attachments, or drone refueling and repair systems.

Standard Beowulf models are powered by sealed hydrogen-oxygen fuel cells. IFVs assigned to high-priority or high-risk missions may be retrofitted with elerium power cells to boost power and performance.

Ships and Vehicles: Fusion Lance

The fusion lance is a multi-kiloton-scale thermo-kinetic weapon that directs extremely high-powered bursts of energy into a short-ranged beam. The fundamental design consists of an elerium-powered energy core contained within a vahlenite casing that shapes the detonation. The elerium core is exposed to massive particle bombardment, triggering a detonation and energy release on a nuclear scale, which typically annihilates both the missile and the core. The vahlenite casing shapes the resulting blast so that the majority of the energy expands in a cone directed forward before the explosion completely destroys the missile itself. Experiments with use of vahlenite kinetic penetrators propelled by the detonation proved unfeasible, as the penetrators would be warped or melted altogether by the sheer amount of heat.

Because of the raw thermal energy release, fusion lances completely disregard kinetic barriers, and typically burn through vahlenite plating to destroy the ship underneath. However, the effective range of the blast is significantly shorter than that of GARDIAN defenses. Coupled with their extreme expense, fusion lance missiles are rarely used except in later stages of battle when heat buildup has reduced GARDIAN effectiveness enough that commanders are willing to risk the extremely costly munitions.

Ships and Vehicles: Starship Weapons and Tactics

Despite the advent of plasma, laser, and fusion lance weapons in space combat, general tactics have largely remained the same. The kinetic barrier and kinetic weaponry remain the deciding arbiter in the majority of engagements.

At extreme ranges, warships engage with mass accelerators, attempting to target enemy vessels and predict their movements. These engagements typically resemble an artillery duel, especially when dreadnoughts are involved. Drones and manned fighters may be deployed from carriers to harass enemy ships, and long range plasma may be employed in an attempt to increase heat-buildup in target ships to degrade their performance. Cautious commanders attempt to weaken the enemy from range before committing to an assault, while aggressive commanders push cruisers and frigates closer. Frigates and fighters may be sent through wormholes to skirmish with enemy fleet elements or attempt to target strategic assets within the system.

At long ranges, the main guns of cruisers become useful. Friendly interceptors engage enemy fighters until the attackers enter the range of ship-based GARDIAN fire. Wormhole-deployed fighter and frigate strikes continue. Dreadnoughts fire from the rear, screened by smaller ships. Commanders must decide whether to commit to a general melee, hold position in long-ranged battle to further weaken the target, or retreat.

At medium range, ships can use broadside guns. Fleets intermingle, and it becomes difficult to retreat in order. Ships with damaged kinetic barriers are vulnerable to wolf pack frigate flotillas and fighters with swarm missiles that speed through the battle space. Casualties may have begun to mount by this point, and plasma fire intensifies, either against ships with disrupted kinetic barriers or to further degrade performance. Fusion lances may be used to destroy high-priority targets.

At close range - under one hundred kilometers - GARDIAN becomes a viable option, destroying fighters and burning through starship armor. Warship exhaust becomes a severe hazard. Wormhole deployments become risky as so many ships exchange fire.

Ships and Vehicles: Hyperwave and Wormhole Tactics

Hyperwave systems enable commanders to observe enemy positions and movements from the edges of a star system in real-time and plan precise attacks using standard mass effect faster-than-light drives or wormholes. Sudden, "bolt from the blue" attacks are a hallmark of human tactics.

Because hyperwaves can only scan a small area, they are typically employed to observe known celestial bodies. A ship or facility hidden in deep space is virtually impossible to locate due to the vast distances.

Accurate wormhole-based strikes are dependant on hyperwave scanning to put them at precise positions. Because all objects in space are in motion, even a few seconds' delay can result in a wormhole being opened vastly off-target. A distinctive radiation burst also accompanies the formation of a wormhole, just ahead of its actual appearance, which can alert defenders to an incoming attack. For this reason, achieving total surprise is often dependent on mass effect FTL systems; by the time the Cherenkov radiation burst has been registered, the attacking ships have already emerged in position and are firing.

Firing munitions such as disruptor torpedoes or fusion lances through wormholes is a viable option, so long as the target is not allowed to align its defenses toward the wormhole. "Bolt from the blue" missile strikes are often ineffective by themselves, as modern GARDIAN systems automatically target any wormholes they detect and fire upon munitions the moment they emerge. Common tactics involve distracting the defenders with swarms of frigates and drone fighters and then launching missiles through wormholes while they are engaged, although opening a wormhole close enough is often a challenge due to the targets being constantly in motion during battle.