Forerunners (Earth-4001)

The Forerunners (Latin Primoris prognatus, meaning "Firstborn") were an ancient species of technologically advanced beings whose empire—known as the ecumene—encompassed three million fertile worlds in the Milky Way Galaxy. The Forerunners reigned for millennia as the ascendant civilization in the galaxy until the activation of the Halo Array, their Pyrrhic solution to halt the Flood, in 97,445 B.C. Although they themselves are essentially extinct, evidence of their existence remained, spread across the galaxy in the form of numerous creations, installations and artifacts.

The Forerunners took upon themselves the role of caretakers of the galaxy, and believed that this "Mantle" had been passed down to them by the Precursors, an even more powerful race that preceded the Forerunner civilization. "Forerunner" is a literal translation of the species' name for themselves; they identified themselves as such because they believed that they held an impermanent place in the universe's Living Time, though, in time, they too would be succeeded by other, superior races. Before their disappearance from the galaxy, the Forerunners would name humanity their successors, identifying them with the title "Reclaimer."

In modern history, the alien hegemony known as the Covenant mythologized the Forerunners and revered them as gods, deriving much of their own technology from Forerunner artifacts found throughout the galaxy, and held that any who defaced these relics were heretics.

History
The history of the Forerunners is the same as their mainstream counterparts up until the end of the Human-Covenant War in 2553.

Physiology
The Forerunners were a bipedal species resembling humans in overall shape, though they were larger in stature. Over the course of their lives, Forerunners underwent a number of artificially-induced mutations, modifying their bodies to better suit the field of work of their rate. More specific aspects of their appearance varied with lineage, age and even personal tastes. They relied heavily on personal body-assist armor which, in addition to protecting the wearer from harm, augmented their physiology and mental faculties. Among many other advantages, it made their lifespans virtually indefinite by providing constant life support and medical care.

Before their first mutation, as Manipulars, Forerunners were tall and slender, and possessed patches of fine, purple-pink or white fur on the top of their heads, along their nape and shoulder area, as well as the backs of their hands. Their facial features were similar to those of humanity, and they were capable of making analogous expressions, but this changed as they mutated to their higher forms, which characteristically had stiffer facial muscles and a more limited ability to convey emotions. There was also a cultural stigma associated with expressing emotions; while even certain higher forms were capable of producing some semblance of a smile or laughter, for example, such uncontrolled display of emotions was regarded as barbaric. Unlike humans, Forerunners lacked pronounced noses or ears, having two slitted nostrils and a set of bulbous protrusions instead. Their skulls otherwise bore a very strong resemblance to those of humans, with subtle differences. The Forerunners also had a genetic code that was remarkably similar to humans, though they were not known to be genetically related.

The Forerunners exhibited sexual dimorphism largely mirroring that of humans, with the females being more slender and somewhat smaller in stature than the males. The height of higher-form males ranged from around three to four meters; for example, the Ur-Didact was three and a half meters tall, while Bornstellar's father, a high-ranking Builder, was around four meters. Bornstellar's mother, a female Builder of the same social standing, was just over two meters in height, while the Librarian, head of the Lifeworker rate, was nearly three meters tall. Males of higher forms also bore less resemblance to humans, while the females appear to have been more human-like in appearance. A large portion of this dimorphism was artificially induced with their mutations and determined by rate.

Their skin color ranged greatly, including gray, black, blue, pink, or a mixture thereof. The number of fingers Forerunners possessed varied according to their rate and form; the most common number of fingers per hand appears to have been six, with two opposable thumbs, although some Lifeworkers could have as many as seven fingers per hand. Meanwhile, the Librarian had only five fingers in each hand, although this was a deviation from the norm.

Thanks to their advanced life-support and medical technology, Forerunners could maintain a youthful appearance for thousands of years should they so choose. Even though Forerunner armor was capable of healing most injuries which would otherwise be certainly lethal, including fatal doses of radiation, on rare occasions Forerunner individuals may choose to decline basic treatment; the ancient Warrior-Servant known as Bitterness-of-the-Vanquished, for example, chose to remain blind and instead relied on her armor to provide sensory input for her.

While the Forerunners had a biological need to sleep, this necessity was eliminated by the use of personal armor which allowed them a constant continuity of consciousness without having to sleep; only on rare cases, they would experience diagnostic waking dreams. As such, Forerunners slept very rarely, mostly doing so by choice in instances such as long stretches of space travel, which themselves were rare due to their exceedingly fast slipspace technology.

Forerunners possessed highly advanced mental capabilities, far beyond those of a human in the case of their higher forms. These abilities were further augmented by their use of personal armor, which integrated with the wearer neurally and stored sensory information and memories, even consistently backing up the wearer's consciousness. The armor also allowed Forerunners direct information transfer to one another, which could also be employed in the form of "silent conversation". Higher-form Forerunners had the ability to process enormous amounts of information simultaneously; for example, Warrior-Servant commanders could simultaneously process the sensory input of thousands of their subordinates while coordinating large-scale battles and themselves experiencing reality in multiple separate frames of reference with variable streams of time. The use of an ancilla enabled Forerunners to recall any past event with exact accuracy, and even without armor or a personal ancilla they could remember enormous amounts of precise information; for example, the Didact was able to recite a verbal control code consisting of hundreds of completely random words and numbers after thousands of years.

Mutation
When a Manipular was ready to work within a particular rate, they would undergo an artificially-induced transformation into a more advanced form, which differed depending on the Manipular's chosen caste. Referred to as a "mutation", the transition typically occurred over a long period of time. A typical Forerunner would undergo several mutations over the course of a lifetime, though this was not always the case. Mutations altered Forerunners' abilities and physical shape to suit their class; Warrior-Servants, for example, underwent mutations that made them stronger and more robust. After their first mutation, Forerunners also gained the ability to access the Domain, a realm of information where the entire collated knowledge of the Forerunner civilization was contained.

In emergency circumstances, an operation known as a "brevet mutation" could be performed on a Manipular. This was a mutation that occurred over a much briefer period of time, and was often painful. Rarely, a brevet mutation could fail and result in deformities; there were rumors that Forerunners whose mutations had failed were sequestered in special enclaves, hidden from the general population. The Ur-Didact performed a brevet mutation on Bornstellar-Makes-Eternal-Lasting to give him access to the Domain.

Society & Culture
The Forerunner civilization was based around the Mantle of Responsibility, a belief that it was their role to protect all life in the galaxy; it was generally believed that the Forerunners had gained the Mantle as a birthright from the Precursors after they vanished. As a result of their perceived status as universal guardians, the Forerunners largely secluded themselves above other species. They monitored the evolution of other sentient species throughout the galaxy, intervening in ways that ensured their civilizations would follow paths of peace, free of conflict, but also so that they would not challenge Forerunner dominance. To maintain their position, the Forerunners committed acts such as relocating other species from their homeworlds in order to expand their own empire or gain control of new resources. They also enforced the Mantle by hindering the development of other species, even reducing opposing species to small populations of specimens, as they did with early humanity. Those species who submitted to Forerunner rule lived within the ecumene as subject species, allied with but ultimately subservient to the Forerunners; some of these species helped eliminate pockets of human resistance after the human-Forerunner wars.

The Forerunners themselves were a race almost entirely without conflict; although political disputes were not uncommon, violence or war between Forerunners was almost unheard of, the last Forerunner civil wars having been fought half a million years before their civilization's end. As such, the Warrior-Servants, who conducted most of the Forerunners' military operations, were often looked down upon by the higher rates, as their actions were perceived to be contradictory to the Forerunners' role of preserving life. While they generally strove for peace, when provoked to a war, the Warrior-Servants would carry out the war ruthlessly and thoroughly, as they believed defiance of their rule was equal to showing contempt to the Mantle itself. One example is the human-Forerunner wars, where many humans were executed following their defeat, and all traces of human achievement was erased from the galaxy.

Forerunner culture was highly stagnant; the fundamental aspects of their society—such as their rate-based social hierarchy—remained unchanged for millions of years. The Forerunners had a rigid social structure, where one's position would be determined mainly by their rate, part of a complex system of different social classes mainly based around a particular occupation. Cultural practices and customs varied by rate and position; generally, Forerunner culture was full of formality and ritual, particularly with the Builders, the highest of the rates. Forerunners placed a great deal of value on family lineage and tradition, and one's rate and social standing were largely hereditary. When Growth-Through-Trial-of-Change, born to a Builder family, chose to become a Lifeworker instead, she was treated as an outcast by her family.

A central aspect of Forerunner culture was the Domain, a vast repository of information containing virtually all knowledge collated by the Forerunners over the eons, including impressions the deceased, leading the Forerunners to also view the Domain as a form of afterlife. Although the Domain permeated Forerunner society for countless millennia, its origin or true nature remained mysterious to the Forerunners themselves. The Domain was best understood by the monastic class of Haruspices, who dedicated their lives to the study of the Domain. While unknown to the Forerunners, the Domain was actually a neural physics-based Precursor construct, and as such was destroyed when the Halos fired, taking most of the Forerunners' recorded history and knowledge with it.

Despite their lack of need to sleep as a result of the use of personal armor, Forerunners had certain moments where each member of a household would retreat for several hours of individual meditation. These moments were typically arranged according to the local day-night cycle, and were sacrosanct in traditional Builder families. During this time, the activities on an entire planet would slow down, including traffic and even the operations of ancillas.

Forerunners did not eat meat, as the Forerunners' scripture surrounding the Mantle forbade "the eating of the flesh of unfortunates". Taking one's own life was also gravely forbidden. Despite their in many ways conservative society, nudity or sexuality were not considered taboos in Forerunner culture; for example, it was normal for both participants to be naked during the rite of mutation, without the procedure being considered explicitly sexual.

Some Forerunners rejected their advanced technology, including personal armor, and adopted a more austere and primitive lifestyle in seclusion from the rest of Forerunner society. One such community existed on Seaward, which would incidentally become the first planet in the Forerunner ecumene to be overrun by the Flood.

Government
The Forerunners' primary governing body was known as the Ecumene Council. Based in the capital, it was led by the First Councilor and composed of five hundred Councilors, in addition to support by a network of ancillas known as the Council metarchy. The Councilors, who came from various rates, typically served for a thousand years and led humble lifestyles. The capital also housed the ecumene's primary judicial institution, known as the Capital Court, which could be assembled into the Supreme Mantle Court in times of great crisis.

Societal Classes
Forerunner society was divided into a number of different classes known as rates, each rate specializing in a particular field of work. The Builders, who designed most Forerunner technology, from ships and weapons to their various megastructures, were the highest rate and wielded the most political power. The second rate were the Miners, who obtained construction materials for the Builders' projects and were responsible for planetary and stellar engineering. Below the Miners were the Lifeworkers, who were responsible for medicine and biological research. The Juridicals were a rate whose duties encompassed legal matters within the ecumene. The Warrior-Servants served as the primary fighting force of the ecumene, while the Engineers maintained technology and machinery.

The rates, in turn, were divided into smaller units, guilds, Maniples and clans. Adolescent individuals, known as Manipulars, were not considered to be part of a rate until their mutation into first-form. During special occasions, each rate of Forerunners wore unique ceremonial headgear except for one day of Grand Star Season, when all rates would wear similar headgear.

Family & Marriage
Forerunner customs involving marriage were said to be complex; they married for a variety of reasons, though it was said that the lower rates married more often for love, while there were often more complex reasons such as familial relations involved in the courtship of higher rates such as Builders. Intermarriage between rates was not unheard of; for example, the Didact, a Warrior-Servant, married the Librarian, a Lifeworker. Additionally, a certain degree of courtship between rates was considered commonplace before individuals were espoused to formal marriage. Polygamy was also an accepted practice, at least among the higher rates, as demonstrated by Master Builder Faber having many wives. At certain points in their lives, females would enter a "millennial interim", a period when they would not bear children.

The rates, in turn, were divided into smaller units, guilds, Maniples and clans. Adolescent individuals, known as Manipulars, were not considered to be part of a rate until their mutation into first-form. During special occasions, each rate of Forerunners wore unique ceremonial headgear except for one day of Grand Star Season, when all rates would wear similar headgear.

Languages & Scripts
Forerunners spoke a variety of languages. Some dialects were older than others, and accordingly were less widely used. Digon was an ancient language used by Prometheans, while Jagon was a slightly less old language used by Builders.

The most commonly encountered system of Forerunner glyphs seems to be based on a series of circular, complex shapes. The glyphs have been inscribed almost everywhere Forerunners were once present, from different areas of Earth, to the Halos. They were also known to put these glyphs and symbols onto their weapons, machinery and clothing, something the Covenant also copied, evident with the Forerunner symbols placed on the hilt of the energy sword and on the Sangheili combat harness. Among the most well-known glyphs are the "Mantle" and "Reclaimer" symbols, as well as the sigils of individual Forerunners. Some variations of Forerunner symbology possess a strangely attractive, even disorienting quality to humans.

In addition to the well-known symbols and glyphs, the Forerunners also utilized a more conventional writing system. The characters used in Forerunner writing have been described as resembling a series of dots, squares, bars and triangles. The Covenant writing system is derived from the original Forerunner script, although they use highly embellished variations of the simple, geometric characters used by the Forerunners.

Naming Conventions
Forerunner names had concrete meanings in their language, and commonly consisted of a combination of words expressing positive attributes in a grandiose, somewhat poetic manner. In many cases, a Forerunner's name was associated with typical terminology involved with the practices of the rate they were born into; for example, "Bornstellar-Makes-Eternal-Lasting" reflects his Builder lineage. In informal conversation, these names were typically shortened, with only a single part being used.

Many, though not all, higher-ranked or older Forerunners were only known by a title not given at birth but rather adopted at one point in the Forerunner's life, often originating as a sobriquet given to that individual due to one of their traits; for example, the Didact, born Shadow-of-Sundered-Star, gained the name "Didact" from his students while teaching in the War College. Manipulars were identified as "Form Zero" in their full names.

Funerary Rites
When a Forerunner died (usually by accident or, on rare occasions, during war) elaborate ceremonies would be enacted before their remains were disposed of in fusion fires associated with the activities of their rates — a melting torch or planet cutter, for example.

First, the Forerunner's last memories would be extracted from their armor, which preserved a few hours of the occupant's mental patterns. This reduced splinter of personality would be placed in a time-locked Durance with a half-life of more than a million years. The body would then be torched in a solemn ceremony attended only by close relations. A bit of plasma from the immolation was preserved by the appointed Master of the Mantle, who secured it along with the essence in the Durance. The Durance was then given to the closest members of the dead Forerunner's family, who were charged with making sure that it would never be abused. Families and rates were very protective of such places, and tampering with a family Durance was considered sacrilege.

Space Travel
Traditionally, Forerunner space travel involved several rituals. When a Builder family was returning from an interstellar journey, the entire family would stand at the bridge deck and observe the ship's approach. The senior family member would issue commands in ancient Jagon. These actions were entirely ceremonial, as nearly all Forerunner ships were controlled by an ancilla.

After making a slipspace jump, Forerunners of high position, including Councilors, would conduct a ceremony where they formally congratulated the ship's ancilla and would in turn receive a small golden disk containing the cost of particle reconciliation for the journey.

During prolonged space journeys, Forerunners would often play "diverting games" through their armor to pass the time.

Technology
The Forerunners' technological achievements were without parallel in the known galaxy. They managed to create solidified surfaces out of light by using technology known as hard light, use slipspace to teleport between locations almost instantaneously, and create numerous forms of advanced machinery. Another of their greatest achievements is their ability to initiate premature stellar collapses of stars and create planets in less than 10,000 years. The Halo Array and the shield worlds are, above all others, the most significant pieces of surviving Forerunner technology. The planet Onyx and its inner Dyson sphere, Shield World 006, in particular demonstrated both their ability for engineering on a grand scale, and their near-transcendent grasp of slipspace technology. Forerunner technology is remarkably resilient, being able to remain intact for over a hundred millennia.

Even after millions of years, Forerunner technology still advanced at a comparatively rapid rate, with a number of new breakthroughs and developments occurring within even a single millennium. It was believed by some Builders that the Forerunners had possessed more advanced technologies in their distant past that they had later lost during periods of technological regression. This was at least partially true, as demonstrated by ten-million-year-old Forerunner probability mirrors, used for large-scale spacetime reconciliation, and similarly ancient cloaking technology used to obfuscate the interior of an entire star system in the Large Magellanic Cloud.

They employed a wide variety of artificial intelligence constructs, generally known to them as ancillas. These ranged from simple personal assistants integrated in their armors to various kinds of robotic Monitors and immensely powerful metarch-level AIs, of which the most sophisticated type was the Contender-class.

The Forerunners had mastered the use of various energy fields, including buffer fields which they used to manipulate gravity, constraint fields used to restrain individuals, confinement fields used to block the movement of entire ships, and the containment and collection fields they used to harness entire stars for energy production. Entire planets could be made habitable even in conditions of lethal stellar radiation via planetary shields.

The Forerunners had an unparalleled knowledge of quantum science, which enabled them much of their sophisticated technology. After a number of instances of catastrophic data loss in their history, they had abandoned conventional digital storage in binary code entirely in favor of storing information in substrates of quantum foam. Virtually all Forerunner technology was powered by harnessing and draining the energies of untold numbers of nascent alternate realities in the form of vacuum energy. This enabled the Forerunners to harness enormous amounts of energy, with a single slipspace-based transmission noted as requiring more energy than the generation capacity of all UNSC assets combined.

In addition to their superior grasp of slipspace travel, the Forerunners had mastered many other methods of higher-dimensional manipulation. They were capable of altering the fabric of time and space within contained "bubbles" of slipspace, allowing the storage of enormous masses and volumes within a comparatively tiny space; as an extreme example, the 300-million-kilometer Shield World 006 was held in a space only 23 centimeters in diameter in normal space. In these bubbles, the flow of time could be suspended altogether, or numerous millennia could be made to transpire while only seconds had passed in normal space. The Forerunners routinely employed the higher dimensions of slipspace in their fleet engagements and created defenses which extended into slipspace, most prominently the Maginot Line.

Forerunner technology could also produce certain objects remarkably quickly without extensive production facilities. For example, personal armor could be manufactured by small engineering units on board a starship, and entire ships could be "grown" from a "design seed", being manufactured on-site from preprogrammed "blueprints" and construction materials obtained from local resources. Likewise, certain automatons — such as Promethean Crawlers — could be "conjured" on-site and constructed in a matter of seconds from raw materials present in the ground. Most Forerunner technology could disassemble and reconfigure itself into a completely different form, and automatically gather any additional construction materials if necessary; this was demonstrated when the Librarian had a Gargantua-class transport use both itself and resources mined locally to construct the Portal at Voi. The Forerunners did use dedicated production plants for large-scale industry. An example of this is the vast Sentinel manufacturing facility on Onyx, which could produce a new Sentinel every six seconds.

The Huragok, nanomechanical "supercomputers" created by the Forerunners for the purposes of maintaining their technology, remained behind after the activation of the Halo Array. Many were eventually incorporated into the Covenant.

Forerunner spacecraft used special crystals embedded in their slipspace drives to travel through slipspace. In order to move through ordinary space, they utilized reaction drives which harnessed virtual particles as a propulsive force; however, they still required the use of onboard reaction mass. The reaction drive of a mere automated cargo transport allowed travel from Edom to Erde-Tyrene, (a distance of 100 million kilometers at the time), within forty-eight hours; this was considered a mundane trip that did not warrant slipspace manipulation. In addition, the Forerunners created a network of slipspace portals for high-traffic slipspace transit across the galaxy. Aboard starships, limited inertial dampening was achieved through the use of buffer fields, but during extreme acceleration, the occupants' armors had to be locked to the deck.

Forerunner warships could be enormous in scale; the most recent models of Fortress-class vessel were around a hundred kilometers in length, while the Didact's personal command vessel, Mantle's Approach<, was 341 kilometers in height and was even then surpassed in size by the largest Forerunner ships.

The interiors of all Forerunner ships were not entirely composed of matter; for example, the structure of a planet-breaker was only half matter, with one third being fuel and reaction mass and the rest being comprised of hard light, allowing the captain to configure the ship's internal layout and decoration at will. At least some types of Forerunner craft can alter their geometry to better suit their current situation; for example, making the ship more aerodynamic in preparation for surface landing.

Forerunners could also create upgrade seeds to upgrade vessels of other species into seamless hybrids of their original technology and Forerunner technology. The inclusion of a Forerunner slipspace flake would give the vessel a Forerunner slipspace drive. Other known upgrades include stealth capability, upgraded weapons, comm and navigational systems kept within the framework of the ship's original operating functional capability.

Communications & Sensors
Forerunners used a type of quantum entanglement for communications, allowing instant data transfer over vast distances. These communications were routed over proprietary encryption protocols, which could be used to track the source or destination of the communication. Forerunners did not use electromagnetic radiation (light, radio, microwaves, etc.) to communicate, presumably due to latency, interference, and security issues. Despite this, mundane radar emitters still played a role in short-range detection of incoming objects, such as on Seclusion Spiral, a remote gas mining station. They also used a form of superluminal communication involving wormholes; however, these communications were significantly slower than communication via the Domain.

Forerunner sensors were capable of instantaneous scanning and detection across interstellar distances. As a particularly impressive example of their available sensor ranges, the Forerunners' core authority routinely tracked individual slipspace jumps across the galaxy. They were also capable of viewing various alternate spaces adjoining the physical universe—including denial of locale, natal void, shunspace, trick geodetics and a photon-only realm known as the Glow—and ascertaining events or objects in normal space through their signatures sometimes visible in these realms. Forerunners shipboard sensors were also highly accurate, being capable of providing a detailed analysis of a single planet's geological and ecological composition from lightyears away through the use of long-range entanglements.

The Forerunner government used an automated network to collate data from all technological equipment across their ecumene, from mundane devices such as a jetbrush to communications satellites and space stations; overseen by non-intelligent automatons, the system filtered unusual observations and relayed possible significant anomalies to the authorities, specifically the Prelate. Such anomalies included catastrophes or "Xenovents" - supposedly referring to contact with alien lifeforms. This is how the Forerunners first learned of the Flood's reemergence around 97,745 B.C.

"Luminaries," which were originally designed to pinpoint Forerunner technology, were used to find "relics" by the Covenant. They are also capable of locating Reclaimers. A misunderstanding of a Luminary's readings led to the outbreak of the Human-Covenant War.

Forerunners utilized various camouflaging technologies, including dazzlers, which generated visual and auditory delusions, or bafflers, which created geometric distortions that could effectively hide a large area not only from plain sight, but also a starship's sensors. Cloaking systems were standard on most warships, ranging from small attack harriers to enormous command ships like Mantle's Approach. While ships could not use their energy weapons or projectiles while cloaked without giving away their position, gravitic weaponry allowed the ship to remain undetected.

Pattern Transfer
The Forerunners were capable of extracting an individual's complete mental and biological patterns and memories, which could then be encoded in either another biological body or stored as data. A Forerunner could create an offshoot of their consciousness housed in an ancillary system, as the Librarian did on Requiem. An individual's pattern could also be imprinted over another body; an example of this was the Ur-Didact's creation of the IsoDidact. Typically, a dead Forerunner's final memories were recovered and stored in a time-locked container known as a Durance. An abstracted consciousness could also be used as a template for an ancilla; 343 Guilty Spark was created in this manner.

The Forerunners had the technology to reproduce entire individuals from encoded DNA/RNA/silicon samples in data streams. This was the primary manner of indexing biological beings during the Conservation Measure; due to their lack of resources, the Lifeworkers were forced to reduce most specimens into data, although their patterns and memories would be reconstituted during the reintroduction. Recovered essences or specific commands could also be coded into a sentient being through a genetic imprint known as a geas, which could potentially be passed on for numerous generations, with encoded memories or actions programmed to trigger under specified circumstances.

As part of an effort to protect themselves against the Flood, the Forerunners created a machine known as the Composer. Designed to process Flood victims en masse, the Composer also reduced its targets to ash, denying the Flood access to any biomass. In the original plan, new bodies would be created for the abstracted individuals, now free of infection. However, the Forerunners never mastered the process and the victims' original forms could no longer be restored. The Composer was later used by the Didact in an attempt to create an army of Promethean war machines, which led to his imprisonment on Requiem.

Weaponry
The Forerunners used a broad variety of weapons, encompassing various forms of directed energy weaponry as well as electronic warfare and offensive technologies based upon energy fields. Forerunner energy weapons proved to be very effective when battling the Flood, burning Flood forms to the point that they cannot be revived by infection forms. Additionally, after the Flood's emergence, certain weapons were designed to disintegrate their targets upon inflicting a critical hit, preventing the Flood from making use of any biological matter.

Forerunner infantry weapons utilize various forms of ammunition, including hard light, accelerated beams of ionized particles, antimatter, or combinations thereof. Although many, such as the Scattershot and Lightrifle, fill relatively basic roles and have clear analogues in human weaponry, many of these weapons also have exotic properties, such as the Scattershot's ricocheting projectiles or the Boltshot's secondary burst function. Forerunner ground forces also use pulse grenades which generate an energy-drain field before collapsing, destroying any targets within its effective radius. In most contexts these weapons are operated by dedicated automatons, one example of which are the bipedal armiger constructs. When participating in combat operations, the biological Forerunners themselves used advanced exoskeletons called combat skins which ranged greatly in size and capability from more conventional, ground-based battle suits to much larger infantry armatures that were capable of spaceflight, such as war sphinxes and seekers.

The many varieties of Forerunner sentinels carry a wide array of weaponry. The Aggressor Sentinels use moderately effective beam weapons, which can also be wielded by humans and certain Covenant races. Meanwhile, Enforcers are equipped with missile launchers and a pair of pulse beams, which fire clusters of smaller red Needler-like projectiles or bolts of energy at an incredibly high rate of fire. The Sentinels of Onyx had significantly more powerful weaponry and shielding. Their energy weapons functioned via a single, slow-charging, extremely powerful golden beam which was effective against energy shields and armor alike. The Forerunners also constructed stationary automated turrets, resembling stripped-down sentinels. Monitors are capable of defending themselves with high-powered pulse weapons akin to those used by Sentinels, as well as with gravity manipulation technology. As one example of Forerunner weapons technology, certain types of beams could be merged into one stream to amplify its power; this capability was used on both infantry weapons as well as starship weaponry.

Forerunner weapons are manufactured out of various forms of exotic matter on an atomic level in hyper-precise nanofabrication forges in accordance with instructions programmed into design seeds by Forerunner pattern-weavers working in conjunction with an ancilla. Because of the fidelity of these manufacturing methods, every weapon and piece of technology could be built perfectly identical down to the atomic level. While the Builders designed most of their technology to be highly uniform, the Warrior-Servants preferred to craft their weapons and armor to be unique and aesthetically pleasing whenever possible. However, the Warrior tradition of custom-crafted equipment waned almost completely as the Forerunners' war with the Flood became increasingly desperate, leaving little room for design considerations beyond lethality and efficiency. Forerunner firearms, like the rest of their technology, are highly sophisticated; most are composed of disparate parts held together by energy fields and display self-assembling capabilities. At least some Forerunner weapons are designed to operate differently according to their wielder; for example, the Incineration Cannon known as the River of Light will only unlock its full capabilities in the right hands while reducing its destructive power when wielded by a Promethean Knight construct.

Art & Architecture
Forerunner architecture incorporates heavy use of geometric angles, usually at either extremely sharp degrees - Forerunner buildings are usually trapezoidal - or at forty-five degree angles. Most Forerunner architecture is constructed with a special type of silver-gray metal that resists deterioration, bullets, plasma bolts and fire, as made evident by Forerunner structures standing in pristine condition 100,000 - 150,000 years after they were built. However, their resistance to heavy plasma fire is limited; concentrated plasma discharge is capable of destroying some Forerunner architecture. Other structures and certain starships were built with a golden-bronze colored metal.

The Forerunners were also highly skilled at creating stone architecture. Typically, these buildings were built from a pale brown or tan stone. These structures were more subject to wear and aging, but their architectural sophistication remains apparent after 100,000 years. A particularly prominent example of intact Forerunner stone architecture could be found within Onyx's Zone 67, which contained a massive Forerunner city constructed entirely of polished chalcedonic quartz. In some structures, such as the Forerunner complex beneath Reach's Menachite Mountain, patterns and symbols had been embedded in the rock itself by manipulating its mineral inclusions. Most interestingly, certain Forerunner buildings incorporated "mutable" stonework: a stone Forerunner structure in Ontom, Sanghelios featured passages that could shift and change by literally reshaping the stone from which their walls were built.

In addition to physical structures, a large portion of Forerunner architecture is actually composed of sophisticated hard light construction. Such architecture is often crafted in the likeness of corporeal matter, most commonly gray Forerunner metal. Hard light structures can form complex shapes and in many cases, be entirely indistinguishable from physical construction, making it difficult to determine which structural components are made up of actual matter. This technology has many uses, from acting as basic structural components such as platforms or walls to decorating and furnishing everything from Forerunner homes and public spaces to starship interiors. Many Forerunner structures are capable of materializing when needed and then melting away when deactivated, a feature most likely facilitated through the use of hard light. The immaterial and flexible nature of this technology lends it a great deal of uses, but as a drawback, it is susceptible to power failures; nonetheless, certain Forerunner ships, such as the command warship Mantle's Approach, employ hard light bonding as a means of maintaining the vessel's structural integrity. Some Forerunner structures, including many of those on Requiem, incorporate components which float in the air without any physical support.

Many symbols and patterns on Forerunner structures employ complex geometric shapes that appear to operate in dimensions higher than human understanding can comprehend. The Forerunners also decorated the interiors of their structures with a complex pattern of engraved straight lines and applied decorative touches and designs to nearly everything that they built, from structures to weapons. Even Sentinel drones possess small holographic Forerunner script around their "eyes". Some Forerunner structures, most prominently those on Requiem, mark bullet holes and other forms of weapon strike points with a small glyph automatically etched around the damaged portion of the surface within moments of the impact.

The Forerunners were highly skilled at creating natural-looking habitats, such as those of the Halo installations, which tend to be very elaborate and include realistic weather patterns and self-sustaining biomes. Although they are clearly distinct from the natural landscape, Forerunner structures often appear to "grow" out of the surrounding terrain, resulting in an impression of complementing the landscape as opposed to replacing it.

Astroengineering
While the Forerunners' architectural and technological prowess is legendary, their masterpieces also extended to the fields of stellar and planetary engineering.

Shield World 006, a full-size Dyson shell, existed in slipstream space, where planets and stars cannot ordinarily exist. In addition, the slipspace bubble containing the enormous construct was enclosed within Onyx, a planet-sized structure composed of trillions of Sentinels arranged into a complex structural scaffolding and covered by a terrestrial crust. The Forerunners also created many smaller shield worlds, essentially planet-sized Dyson shells with terrestrial inner and outer surfaces as well a miniaturized sun in the center. Some works of Forerunner engineering are also located beyond the confines of the galaxy, including Installation 00, a vast, flower-shaped construct with a terrestrial surface and its own artificial star for illumination. Another example of the Forerunners' mastery of megascale engineering was the Capital, a structure which surpassed even the Ark in sheer enormity and complexity.

In addition to moving and manipulating stars for use in their megastructures, Forerunner Miners, specifically stellar-class engineers known colloquially as "plasma jockeys", experimented with stabilizing young stars. The Forerunners had also harnessed dozens of stars for energy production by using sophisticated energy fields to direct the energy output of a star. Specialized plasma jockey installations were also capable of suspending the collapse of a star, although this was rarely entertained due to the enormous amounts of energy required in the process. In addition to stellar manipulation, the Forerunners were capable of considerably speeding up a planet's formation, artificially collapsing an asteroid field into a molten mass, then cooling it down and forming it into a terrestrial planet in less than ten thousand years; a relatively short period of time for the ageless Forerunners.