For detailed information about this series, please visit the Sword Art Online Wiki.


The year is 2022 and gamers have lined up on launch day for Sword Art Online (SAO), a hotly-anticipated MMORPG that lets players connect to an immersive virtual reality world with special helmets called NerveGear. Kirigaya Kazuto, username Kirito in virtual reality, is one such gamer who's eager to jump back into action, having spent a great deal of time as a beta tester, and quickly befriends the newbie Klein, teaching him the basic mechanics of the game. But soon, Sword Art Online's 10,000 players discover that not only are they unable to log out, the only way they can return to their physical bodies is by beating the 100th floor final boss, and death in the game means death in the real world. Now, with no one else to turn to, Kirito and the other participants must survive the game as best they can.

The Games, Their Lore, Their Mechanics, and Terminology

The Sword Art Online series has a multitude of virtual reality video games and one augmented reality video game, not just Sword Art Online. All of the games, their lore, and their main mechanics are as follows:

In-Game Lore/Setting

Once upon a time, the balance of all creations on The Ground was maintained by the divine protection of the white and black «Great Holy Trees». The Dark Elf race, who are the devotees of the «Black Great Holy Tree», established «Lyusula Kingdom», while the Forest Elves, who are the devotees of the «White Great Holy Tree», established «Kales'Oh Kingdom» and both prospered to a great extent through the divine protection and powerful magic of the Great Holy Trees. Additionally, the «Alliance of the Nine» was established by the human race, the «Underground Kingdom of Aul-Da» was established by the dwarf race; in the company of several small-to-medium nations of several more races, a generally peaceful period among the races continued for a long time.

However, at some point, a group of elves, seeking to obtain bodies impervious to even blades, attempted to hurt the two Great Holy Trees to gain their sap. Their plans were foiled and the group was banished from both kingdoms for eternity. In the legends of the Dark Elves, they were depicted as Forest Elves, while in the legends of Forest Elves, they were depicted as Dark Elves, but before long, both sides began to call them «Fallen Elves».

Having been exiled to the northern region of ice and snow, the Fallen Elves detested both kingdoms and spent many years afterwards attempting to secretly incite war between the two kingdoms. Bit by bit, the tension between the two kingdoms escalated, until finally, with an attempted assassination of the Lyusulan Kingdom's queen, their diplomatic relations were severed. The human Alliance of the Nine and the dwarven Underground Kingdom were divided in their support of the two elven kingdoms, unprecedented tension engulfing The Ground.

And so, in the end, war broke out and the sorcerers from both elven kingdoms were about unleash their largest scale offensive magic, when a disaster took place. A ring of light engulfed the ten kilometer wide field that had become their battlefield, detaching it from The Ground and sending it flying into the sky.

Besides the battlefield, the capital cities of Lyusula Kingdom, Kales'Oh Kingdom, the Alliance of the Nine, and the Underground Kingdom, as well as their main cities were all scooped up by the ring of light. The «disks» numbered a hundred and, upon rising high up into the distant skies, they piled atop each other vertically. Through this incident that was later dubbed as the «Great Separation» the Floating Castle Aincrad was born.

In Aincrad, which had lost the divine protection of the Great Holy Trees, almost all magic was lost while, perhaps due to some kind of force, any arrow fired from a bow became unable to fly straight. Many years since then, the tale of the Great Separation was only passed down to the descendants of the two elven races.

The original ALfheim Online was set in the continent of Alfheim, which was divided into territories, the main ones consisting of racial territories and the minor or smaller ones being controlled by neutral players. At the center of the land was the neutral city of Alne, which was at the base of the World Tree.

Upon the release of New ALO after the scandal generated by Sugou Nobuyuki, a patch was later included to introduce New Aincrad, the floating castle, to ALfheim.

The original basis of ALO is that of a land of faeries, which seek an audience with the king, Oberon. The naming of the fairy king, Oberon, and his queen, Titania, suggests that it holds its roots in the Shakespearean play A Midsummer Night's Dream. Aside from that ALO seems to draw from a wide range of mythologies, including the Arthurian Excalibur, and the naming of the nine realms of Norse mythology like Jotunheimr. The influence of Norse mythology is more emphasized in the evil gods of Jötunheimr and the quest related to them. Yet the appearance of the deities, or Aesir, from the Norse forum is also present such as Thor, Urðr, Verdandi, and Skuld.

Gun Gale Online is set in a post-apocalyptic Earth, which had become a wasteland after a huge war long ago, that people had returned to on space ships. The capital city of the game, called SBC Glocken, with SBC meaning Space Battle Cruiser, was originally the spaceship that was used to return to this planet. A huge city of ruins from the war, which has an unlimited number of automated fighting machines and mutant creatures that await adventurers, sleeps beneath the capital city.

In the third decade of the twenty-first century, the Earth began to be invaded by a parallel world named Unital. Unital opened dimensional gates in various cities on Earth to send in displaced biological weapons known as Displaced Biological Arms (DBAs), intending to launch a full scale attack once enough of them had been gathered.

Having predicted the upcoming invasion, an international organisation known as «The Order» developed a dimensional tuning device, called the «D Tuner», to find the invisible Displaced Biological Arms and destroy them through the use of special «D-weapons» that were created for this goal. The Order then began recruiting Adapts, people compatible with these devices, from the civilian masses for a large-scale Earth defense operation.

Adapts were tasked with using D Tuners to collect energy crystals known as «Materials» that were byproducts of Unital's dimensional gates, and destroy any Displaced Biological Arms lurking in town. Based on these contributions, Adapts are given a Ranking Number that determines the strength of their D-weapons. This Ranking System also allows Adapts to steal Materials from other Adapts, which resulted in conflict among the three factions of The Order, the leadership of which decided to employ a strategy of watchful waiting and not interfere in the internal conflicts.

Spoilers for the Alicization Arc.

Brief History: The Underworld is set in a past era, when science and philosophy were just being discovered, but instead of recreating a past era, limited terrain and certain customs were introduced so that the inhabitants of the world would form their own society.

According to the story told by the Axiom Church, the world was created by the three goddesses, Stacia, Solus and Terraria, but was then split by Stacia and Vector into the Human Empire, overseen by Stacia, and the Dark Territory, ruled by Vector, after Solus drove away Vector to the land of darkness with her holy spiritual light during the world's creation. Ever since that time, the light of Solus has never shone on the lands of the Dark Territory.

In one legend, it is said that once every one thousand years, when the light of Solus weakens, the forces of darkness led by the dark knights would cross the mountain range will invade the Human Empire from the North Cave, West Gorge, South Corridor and East Gate. In that great war, the guards in the villages, the sentinels from all towns and the imperial army would form the Human Empire Army that would be led by the Integrity Knights to fight against the hordes of monsters, while nobles would support the Integrity Knights as the commanders of that army. Until then, the nobles are to polish their swordsmanship in preparation for the battle.

In reality, the existence of the four gods was forged by the Axiom Church to secure its authority over the Human Empire. Although none of the gods truly exist in the world, they are registered as super accounts in the system, though they had never been used since the creation of Underworld.

The Original Four: The population of the Human Empire began around 70 Before HEC with two families of eight Artificial Fluctlights each in a small village at the center of the Human Empire, the village of Centoria. Both of these families had two real Rath employees nurturing them, while the rest of the villagers were simulated with placeholder NPCs. The four members of Rath raised the first sixteen Artificial Fluctlights to adulthood, teaching them everything from reading and writing to cultivation of crops and rearing of livestock to the morality of good and evil, however, one of the four employees lacked ethics and unintentionally corrupted one or two of the children by passing down his egoism and desire for wealth and dominance to them. After the Artificial Fluctlights reached the age of eighteen and started families of their own, the four humans logged out one after another by simulating an "epidemic".

The Growth of the World: After the «original four» logged out, the population of Underworld continued to grow, with the humans marrying when they were about twenty years old and bearing an average of five children, thus the 5th generation already consisted of 600 children, with about 400 still alive from the older generations. The children corrupted by the egoistic Rath employee became the ancestors of the future nobles as they secured their place as elites in the world. By the time of the 5th generation, the inhabitants of the Human Empire were already ruled by several lords, who, inheriting the egoism from their ancestors, earnestly continued expanding the land they owned, thus depriving the descendants of the non-corrupted first humans of land for cultivation. Most of the youth was then forced to work for the lords as tenant farmers, while some of them, who were not content with their social positions, set off from Centoria and traveled to the remote regions where they founded new towns and villages, like Zakkaria and Rulid Village, and thus acquired new land to cultivate.

Meanwhile, the lords that ruled over the capital held enmity towards each other, so there was a long period of time without any marriages between them. However, after some time, a political marriage happened between two families of lords for the first time. As a result of this marriage, a single daughter, possessing a higher level of egoism than any other lord in the world at the time, was born.

The Axiom Church: The Axiom Church was founded around 30HEC (100 years after the creation of Underworld). At the time, the founder and head of the church was a girl named Quinella. Her Sacred Task was one not seen before in Underworld: "Sacred Arts Research". She soon became very proficient at the Sacred Arts and had discovered many new rituals that people could use in every day life. At the age of thirteen, Quinella decided she didn't want to rule over the people as a lord or baron - she wanted to have absolute control, she wanted to become God. To do this, Quinella started doing "miracles" in front of people, predicting storms and healing sick and injured people in the name of "god". She told the people that a shrine to worship god needed to be built in order to perform even greater miracles, hence a large marble spire was erected in the center of town. This was the beginning of the Axiom Church.

Years later when Quinella felt her life was coming to an end, she desperately tried to find a form of Sacred Arts that could manipulate her «Life». Even at the verge of death, she still tried chanting various combinations of verses in the hopes of finding something that could help her. One fateful night, when she was just on the brink of death, Quinella discovered the Sacred Art: “Inspect Entire Command list”, and at the bottom of this list was the command that Quinella had been searching for, the one that would let her truly become God. This command that she had found was one that took the administrator powers from Cardinal and transferred them to Quinella, allowing her to then use all the controls that administrators had access to, including the manipulation of «Life». Even after this act, Quinella's thirst for power was not satisfied and so she tried to eliminate the one thing that held equal authority to her, the Cardinal System, but accidentally ended up infusing it with her Fluclight. By doing this, she became less human and adopted the primary purpose of the Cardinal System: to preserve the Human Empire exactly as it was.

Quinella then created the Immortal Walls in Centoria which divided the Human Empire into four. This was to create a physical barrier between the people and to make sure that the Axiom Church would have complete control of the relaying of information. She made it so that the people would remain reliant on the church and thus they would stay devoted to its preachings. Large physical barriers including: a huge, unbreakable rock; a swamp that could never be filled; a rapid, uncrossable stream and a gigantic unfellable tree were then put in the world to make sure that humanity could not expand past its current boundaries, effectively stopping all progress in the Human Empire. She also set down rules for the people, including the Taboo Index, and made sure every resident knew them so that no one could possibly oppose her. While this was all happening, the tower of Axiom Church was growing ever higher.

Seventy years after Quinella assumed her position as administrator, she discovered that the capacity in her brain for storing memories was reaching its limit. In an attempt to stop this, Quinella attempted to transfer her memories into a young girl. However, this backfired as a Fluctlight could not bear the fact that there was an exact copy of it. But, instead of both of Quinella's Fluctlights breaking down, the young girl's Fluctlight collapsed a moment sooner and allowed the Cardinal System's error correction program to take control of her body, creating Cardinal. As both Cardinal and Quinella now deemed each other as different beings, their Fluctlight breakdown halted. Cardinal reacted a mere moment sooner and attacked Quinella first. However, Cardinal was eventually overpowered and forced to flee and seek refuge inside the Great Library Room. Afterwards, Quinella started avoiding death by deleting her most recent memories and spending most of her day sleeping on the top floor of the church to avoid filling up her memory capacity. She also started using the Synthesis Ritual on especially strong swordsmen and law breakers to turn them into Integrity Knights, who would fight the monsters of the Dark Territory, keep order among the people and defend her from Cardinal, whom she knew would be back one day to kill her. Cardinal would also try to seek help from humans in her quest to kill Quinella, but every time she found someone that might be able to help, Quinella was able to get to that person first.

Through the Integrity Knights, the Church was able to maintain its rule over the Human Empire for another 200 years. However, the Church's rule became endangered when the «Load Test Stage» began to approach. Even with the great fighting prowess of Integrity Knights they would eventually be overpowered by the sheer numbers of the Dark Territory's forces, even if Quinella herself would join the battle. Knowing this would one day happen, the Axiom Church invented a story that on a day when the light of Solus would weaken, the forces of the Dark Territory would invade the Human Empire. Quinella used this story as a pretext for the foundation of the Sword Mastery Academy.

The Dark Territory: In contrast to the Human Empire, far less is known about the history of the Dark Territory. There was once a time known as the «Age of Blood and Iron», where the different races that inhabited it constantly fought one another. This period came to an end following one final battle, which was so devastating that no living thing other than a lone black lily survived. Afterwards, the races signed a peace treaty and divided the lands of the Dark Territory between themselves. However, there were power plays involved in the treaty, such as in the case of the Goblins, who were given barren plains derived of resources. There were also some who believed the current peace was only a temporary truce to defeat their common enemy, the Human Empire, and that the fighting would begin once more once that goal was reached.

Note: There is so much history and lore surrounding the Underworld and Project Alicization as a whole that it would be absurd to cover it all on this single wiki page. To go into more detail on the project, click this link to travel to the official wiki page.

Out-of-Game History and Game Mechanics

Summary: The very first virtual reality MMORPG (VRMMORPG). Sword Art Online was produced by Argus for the NerveGear, with Kayaba Akihiko as the development director. The online game takes place on a hundred-floor floating castle called Aincrad. Only 10,000 copies were printed in the first batch of the game, and online sales sold out within seconds. Hard-core gamers waited in line for days to purchase the first few hard copies from many stores. «Sword Art Online» officially started server service at 13:00 on November 6, 2022 and obtained infamy when the creator succeeded in trapping 10,000 people in the game, and making it so that death in-game would mean actual death for the player (Known in-verse as the Sword Art Online incident). During the two-year period the game remained active, «Sword Art Online» evolved into an innovative yet complex society of individuals with mixed feelings about the possibility of clearing the game.

Beta Testing: Prior to official launch, «Sword Art Online» Closed Beta was available to 1,000 beta testers for a one month period from August to September 2022. During that period, «Sword Art Online» was lauded as an incredible experience, and it received extremely positive reviews despite the actual difficulty of the game. After the Closed Beta Testing ended, the Beta Testers were given the opportunity to pre-order the game.

The System: The game operates similar to most MMORPGs with a level system and eventual skill mastery with some limits placed on it. The entire game is monitored and maintained by the «Cardinal System», which self-corrects any problems.

  • The Cardinal System: Occasionally referred to simply as Cardinal, the Cardinal System serves as the primary driving and management force of nearly all Virtual Reality MMOs in the Sword Art Online Universe. The system was originally developed by Kayaba Akihiko to have nearly absolute authority on all matters related to the Sword Art Online without requiring any human input, whether that be player monitoring, game balancing or generation of new quests.

Gameplay Mechanics: There is no «Magic» in SAO except for the different colored crystals that bring instant effects. Instead players can fight using their «Sword Skills». Execution of Swords Skills are assisted by the system, and it can fall into any of the four properties: Thrust, Slash, Pierce and Blunt. SAO has no projectile weapons, with the exception of Throwing Picks, darts, boomerangs, and chakrams; all of which are more used for drawing aggro than dealing major damage to an enemy.

It is generally much more efficient to battle in parties. While there is less emphasis on Classes in Sword Art Online (Though there is still the holy trinity of class types available: tank, DPS, and support), the main benefit of battling in parties is the ability to «Switch» (Which is discussed in the Other Mechanics tab). The maximum number of players that can form a party is six. Eight parties (or groups) constitute a complete Raid Group large enough to challenge bosses.

Skills: Abilities that players can use in Sword Art Online. There are various types of skills in Sword Art Online, including Support Skills, Combat Skills, and Weapon Skills. Certain rare skills are also known as Extra Skills or Unique Skills depending on their rarity. Weapon Skills also unlock the use of special, system-assisted weapon techniques known as Sword Skills. Players have also dubbed some of their techniques as Outside System Skills, though they are not actual skills system-wise (and will not be discussed in this section).

  • Sword Skills: Sword Skills are Sword Art Online's combat movements that are assisted by the system. Sword Skills are activated when a player performs the appropriate «Pre-Motion» for a skill, such as raising a sword atop one's shoulder. As soon as the system recognizes the motion, the player's weapon begins to glow in a color specific to a Sword Skill. The player can then allow the system to take over and automatically complete the skill at a speed that is normally near impossible for a player to achieve and dealing much more damage than a regular sword swing. After a skill is completed, the user is temporarily rendered rigid in a state called a «Post-Motion», during which the user is made vulnerable to any counter-attacks. The higher the level of the Sword Skill used, the longer the «Post-Motion» period is. After a Sword Skill has been used, the skill enters a «Cooling» period, which is displayed as a cooling icon at the bottom of the player's view. Until this period ends, the same Sword Skill cannot be used, however, any other learned skills that are not in a cooling period can still be used.
  • Extra Skills: «Extra Skills», also known as «Hidden Skills», are the kind of Weapon Skills in Sword Art Online with no clear conditions to unlock them, however, most of these skills have at least ten known users who are using them. Certain «Extra Skills» are limited to only one known user per skill and are therefore called «Unique Skills». Although the exact condition or the quest required to unlock these skills are not publicly known, two known ways of unlocking «Extra Skills» have been revealed so far. Some of these skills are unlocked by training certain regular Weapon Skills, for example, the «Katana» skill appears quite often, as long as the «Curved Sword» skill is trained. Certain other skills are acquired as quest rewards, for example, «Meditation» is acquired by completing a certain quest on the 6th Floor. Like Weapon Skills, most «Extra Skills», including «Unique Skills», have their own special «Sword Skills».
  • Unique Skills: Unique Skills are «Extra Skills» in «Sword Art Online» that are assigned to only a single player per skill. Like other Extra Skills, the prerequisites for receiving «Unique Skills» are unknown, but they are said to be given to players who fulfill a certain physical requirement.
  • Mods: Certain skills in Sword Art Online have this. Mods can either be special bonuses that increase the effectiveness of the skill (e.g. decreasing Sword Skill cooldown time, increasing the range of the player's detection etc.), or various abilities (e.g. the Tracking mod for the Searching skill). It is known that at least for certain skills, for example, the One-Handed Sword, a new mod can be chosen every fifty levels of proficiency.
  • Composition: Composition or composite effect refers to the combined effect produced with multiple skills. A composite effect is unlocked when two or more compatible skills reach a certain level. For combat skills, a composite effect may result in unlocking a new Sword Skill that makes use of two weapon types. Certain crafting and life skills may also have composite effects. The various compositions available in the game are not listed by the system, thus players have to discover them themselves.

Summary: After Argus went bankrupt due to the Sword Art Online incident, its servers and data were acquired by RECT Progress Inc. and used to create the VRMMORPG ALfheim Online. ALO is loosely based on both fairy lore and Norse mythology, drawing elements from other legends for its setting as well. ALO was released a year after the beginning of the Sword Art Online incident. It is compatible with any FullDive device such as the NerveGear and AmuSphere, the latter of which was developed specifically with safety features to prevent anything like the Sword Art Online incident from happening ever again.

The game features nine races of fairies, whose goal is to reach the top of the giant World Tree, in order to meet the Fairy King Oberon. It was said that Oberon would turn the first starting race to reach the top of the World Tree into the legendary race of ALFs, with the ability to fly for unlimited time, however this later proved to be a lie, and the top of the World Tree was used as a testing grounds for inhumane experiments by a small team in RECT Progress Inc. led by Sugou Nobuyuki. After Sugou's inhumane experiments on 300 captured SAO survivors in the administrator-locked area atop the World Tree in ALfheim Online were made publicly known, RECT and the whole VRMMO industry suffered a huge blow. RECT Progress was disbanded due to said experiments and even the main RECT office suffered heavy losses, while ALO had to be suspended.

At this time, former ALO players who had many people from venture companies, funded a new company, Ymir, which bought all ALO data, from RECT for a very small fee and re-established the world of ALfheim, improving it with several major changes. Once ALO was acquired by the Ymir, unlimited flight, except in dungeons, was granted to all fairy races.

Instead of the level system that Sword Art Online emphasized, ALfheim Online pursues skill development and encourages killing other players. This kind of system attempts to eliminate the enormous gap between new and old players that exists in level-based games.

The System: The system makes the player choose one of nine races of fairies for their avatar, each with different abilities and affinities toward magic. Unlike Sword Art Online's system, the player has their game avatar created randomly and only have the freedom to choose their avatar name and select the race of the character. However, for an extra fee, players can reconstruct their characters to their liking. Skills are developed by the player's own abilities and by repeating them over and over, so a new player with good skills can match a veteran player almost evenly in battle.

  • The Cardinal System: Occasionally referred to simply as Cardinal, the Cardinal System serves as the primary driving and management force of nearly all Virtual Reality MMOs in the Sword Art Online Universe. The Cardinal System in ALfheim Online uses the exact same features as the one from Sword Art Online, however there are many restrictions placed on it, such as not being able to generate world-changing quests unless it's unlocked.

Gameplay Mechanics: Combat in ALO contains multiple elements and strategies. With the introduction of flight, it allows for duels to take place in aerial battles or on the ground. In the original incarnation of ALfheim Online (Called Pre-New Aincrad in this wiki) combat was either between players or monsters, and since there were no Sword Skills, combat consisted of either sword swings or magical attacks. It was noted that general combat involved just the trading of strikes and that high-speed battles, like the one observed between General Eugene and Kirito, were uncommon. In the newer version of ALfheim Online (Called Post-New Aincrad in this wiki), the introduction of features such as sword skills and the creation of the Original Sword Skill system allowed for combat to diversify.

When a player dies, they will become a Remain Light and lose some of their stat progress. The attacker will also receive some of the killed player's items and currency. If a player dies due to a self destruct magic, they will suffer a much greater death penalty than for normal deaths.

Monster battles are the same as those in Sword Art Online, with the difference of including magic and the absence of Sword Skills Pre-New Aincrad.

Flight: The game is famous for being the first game to allow the player to fly for real. It uses a flight engine to enable the player to fly. The flight system also focuses on the player's own ability. It has a "controlled flight" mode, in which the players make use of a controller to fly, at the cost of being able to use only one hand to fight, but, with enough experience and ability, the player is able to learn «Voluntary Flight» and with it, can use both hands while flying and gains more maneuverability and speed.

Skills: Most Skills from Sword Art Online are carried to ALfheim Online, barring sword skills Pre-New Aincrad. Post-New Aincrad introduces sword skills, Extra Skills, and Original Sword Skills, however Unique Skills were not included, likely because only one person was allowed to have one and it would break game balance.

Other Details: ALfheim Online is part of «The Seed Nexus» (Which is explored in more detail in the Other Mechanics/Important Terminology section) Post-New Aincrad, allowing players from other games that are part of the nexus to convert their avatars in the game into ALO and vice versa, though at the cost of not being able to transfer items, having the avatar's stats adjusted to maintain the relative strength between the two games and the player not being able to use the same avatar in the previous game unless it is converted back again.

Summary: A VRMMORPG, developed and operated by an American company called Zaskar, that emphasizes on gun usage. Two of the main events in GGO are the free for all multi-player tournament known as the Bullet of Bullets (BoB) and the team deathmatch multi-player tournament known as Squad Jam (SJ). The game started operation in April 2025 and has become the most famous Sci-fi VRMMO game in the Sword Art Online Universe since then.

Gun Gale Online was created with the help of the free VRMMO game development support package called «The Seed» (Which is explored in more detail in the Other Mechanics/Important Terminology section) and utilizes FullDive technology to set players inside a post-apocalyptic world. It is thus part of «The Seed Nexus» (Which is explored in more detail in the Other Mechanics/Important Terminology section), allowing players from other games that are part of the nexus to convert their avatars in the game into GGO and vice versa, though at the cost of not being able to transfer items, having the avatar's stats adjusted to maintain the relative strength between the two games and the player not being able to use the same avatar in the previous game unless it is converted back again.

The System: Just like ALfheim Online, a player's avatar is randomly generated unless they pay a fee to customize them. As many other VRMMO games, Gun Gale Online also has a system of skills, most of them are related to the weapons the player use, while others are used to create weapons such as «knife creation» and «weapon creation» skills. GGO also uses the Cardinal System just like every other VRMMO that runs on «The Seed», however it's extremely limited compared to Sword Art Online and ALfheim Online's version.

Gameplay Mechanics: The basis of the game's gameplay is to increase one's level, which in turn increases stats that are increased based on player's choices. These stats determine how a character plays and operates in the game, the interval selection can not be altered later, so players must know how they wish to develop in the long-term.

Weapons: There are mainly two types of guns in Gun Gale Online, with each of them have different advantages and disadvantages that limit their use.

  • Optical guns - firing light-based ammunition, they are used primarily to hunt mobs. Their advantages include being lighter, having longer effective range and precision as well as smaller magazine size than live ammunition guns do. However, defensive equipment can be used to disperse the damage of optical weapons, making them ineffective against players. Optical guns are all given fanciful names and shapes.
  • Live-ammunition guns - meant for player to player battles as they are capable of ignoring most counters meant for optical weapons. The bullets of such weapons can pass through defense fields and are able to deal higher damage per hit as compared to optical weapons. However the disadvantages include having to carry extra heavy bullet magazines around and the fact that live bullet trajectory is affected by wind and humidity. Guns in this category are all originated from guns that exist in the real world.
  • Non-gun weapons, like the Kagemitsu G4 (A photon saber), also exist in this game.

Squadron: In place of guilds and parties, GGO uses a squadron-type team play. Some squadrons prefer hunting monsters, while others prefer battling against other players.

Servers: There are two separate servers for Gun Gale Online: the American and the Japanese servers. Until the aftermath of the first BoB, anyone from the American server could choose to play on the Japanese server and vice versa, though only a few players chose to play on a foreign server. This also meant that an American could participate in the Japanese version of the BoB. However, after the first BoB, the two servers were separated, meaning that American players could no longer connect to the Japanese server and vice versa, though an American player did somehow manage to get into the 4th BoB despite the regional block.

Pro Play: To play Gun Gale Online, a player must pay a connection fee of 3000 yen every month. Players are given 6 months window time to pay the connection fee. If a player does not pay the connection fee within 6 months, the account of the player will be deleted.

GGO is the only VRMMO game with «Pro» players, meaning players who make their income solely from the game's «game coin to real money conversion system». They convert credits earned in-game into yen and could use them to pay connection fees, and potentially even for their living.

Because the game is running over legal gray zone, no real world contact information about its operator is provided, thus all game-related operations, like joining activities, can only be done in-game via terminals, which can be found in areas like the presidential estate in SBC Glocken.

Summary: Ordinal Scale is an Augmented Reality Massively Multiplayer Online Role-Playing Game (ARMMORPG) for the Augma, a device that allows the user to experience augmented reality.

The System: The game operates on a ranking system. The player can acquire points by collecting «Materials» in the real world or by defeating monsters (Displaced Biological Arms) or other players (Adapts). Depending on the points each player has, all players are given a Ranking Number. The higher the player's ranking, the stronger their D-weapon and armor will become. The stats of a player and their equipment are not displayed. Unlike most VRMMORPGs in the Sword Art Online Universe, the ARMMORPG Ordinal Scale does not use the Cardinal System, but instead its own system called the Ordinal System.

Gameplay Mechanics: Players can choose from three types of D-weapons: close-range, long-range, and support. As players take part in combat using their actual bodies, feedback to the player is sent through the vibration of their D-weapon and a virtual sense of shock created by the Augma upon dealing or suffering damage. When the player's hit points reach zero, their weapon, armor, and dimensional tuning are temporarily disabled, thus excluding the player from battle. In player versus player battles, damage is only registered via hits made with a D-weapon, displayed in augmented reality as blades or bullets. Direct physical attacks are forbidden by the rules.

Battles against monsters are carried out in special fields that are created beforehand. If the player leaves the field, their dimensional tuning will be cancelled, resulting in monsters disappearing from their sight. Although the player can no longer be attacked, intentionally escaping the field results in a point loss as a penalty.

Spoilers for the Alicization Arc.

Summary: With the end of the Cold War Era and subsequent collapse of the Soviet Union, the people became less tolerant of soldier deaths. However, countries with large militaries, especially the United States of America, were unwilling to abandon their military-industrial complex, thus necessitating unmanned weapons to replace soldiers. However, due to Japan's market not being capable of sustaining domestic production of weapons from scratch as a result of export prohibitions, Japan was forced to either import or co-develop weapons with America. Despite this mutual cooperation, America claimed the cutting-edge technology for itself, while the weapons sold to Japan lacked key features, such as control software for fighter jets. Thus, feeling anxious about relying on Americans for their core defensive capabilities, some military officers and technicians decided to create a technology that would entirely belong to Japan, thus Project Alicization was created. Project Alicization is a top-secret government project run by Rath to create the first Highly Adaptive «Bottom-up Artificial Intelligence (Bottom-up AI)». The Japan Self-Defense Forces (JSDF) intended to use the AI for unmanned weapons to improve Japan's inferior defense technology compared to the West, and to replace soldiers in wars to minimize human casualties. The name Alicization is formed from the acronym A.L.I.C.E (Artificial Labile Intelligent Cybernated Existence, or a highly adaptive artificial intelligence), in reference to the project's goal of turning artificial human Fluctlights into «Alice». The project was mainly conducted within Rath's main base, the «Ocean Turtle», though a secondary alternate facility in Roppongi was also used.

Clarification/The System: Unlike every other virtual reality space before it, the Underworld is not a video game. Instead, it is a complete simulation of another world, down to the stars, the moon, and the entire planet. However, the Underworld still uses the Cardinal System to an extent to shape and control the world.

System Mechanics: Unlike the usual VR games, there is no game menu in Alicization. Instead, a Status Window called a «Stacia Window» can be called out for any object and person by drawing a seal shaped like the alphabet letters S and C with one's hand and tapping the target that one wishes to inspect. However, as the «Stacia Window» is considered as a basic form of «Sacred Arts», calling out the window for larger objects is considerably more difficult than for smaller objects and requires sufficient practice and knowledge in the Sacred Arts. The Status Window shows the ID and current/maximum «Life» values of the targeted object, as well as the item's Priority class if the item is a weapon, or Object Control and System Control Authorities if the target is a sentient being.

As a menu does not exist, an item storage feature does not exist either, meaning that all items need to be carried by hand, while clothes and weapons can be equipped the same way as in real life, instead of via a menu. Logging out manually is also impossible due to this, and it is presumed that only an Administrator can log a player out from within the game.

The stats for any object or living being can be viewed by calling out a «Stacia Window» for them. Everything in Underworld has a property called «Life» while humans also have stats called «Object Control» (OC) and «System Control» (SC) Authorities and certain items, like tools and weapons have a property called «Priority». The OC and SC authorities were implemented for the project's «Pressure Experiment Stage», during which, the residents of Underworld were meant to battle with creatures from the Dark Territory to strengthen themselves.

  • Object Control Authority: «Object Control Authority», abbreviated as OC Authority, is a parameter that determines what kind of tools, weapons and armor the person can wield. A person needs to have an OC authority equal to or higher than the item's «Priority» class to be able to wield the item properly. Swords that have a higher Priority than a person's OC authority cannot be used to perform «Secret moves», i.e. Sword Skills and they will feel much heavier than they should to the user. A sword's Priority determines the maximum hit combo Sword Skills that can be used with it and higher Priority items are also capable of breaking lower Priority items. The OC authority parameter can be increased by killing any creature that is capable of moving, even other people, but a larger increase in the parameter is awarded for killing creatures from the Dark Territory.
  • System Control Authority: «System Control Authority», abbreviated as SC Authority, is a parameter that determines what «Sacred Arts» rituals one can use and their success rate. Like OC authority, SC authority can be increased by killing any creature capable of moving, creatures from the Dark Territory providing a bigger increase, or through steady use of the rituals, even if they are not performed successfully, but with a bigger increase with successful difficult ritual usage.

Sacred Arts: «Sacred Arts» are System Commands in Alicization that residents of Underworld believe to be magic rituals. In reality, they are just words used to arrange thoughts and guide the emotions of the caster to make use of one's imagination power. Because of this, the imagination of the user may either improve or decrease the effectiveness of an art.

Secret Moves: «Secret Art Finishing Moves», usually shortened to just «secret moves», is the name that Underworld residents have given to Sword Skills existing in Underworld. It is currently unknown how these skills were implemented in Alicization, as ALO, which uses a complete copy of the SAO servers, is the only game that has the data for Sword Skills, since «The Seed» package does not include them.

Note: There is so much history and lore surrounding the Underworld and Project Alicization as a whole that it would be absurd to cover it all on this single wiki page. To go into more detail on the project, click this link to travel to the official wiki page.

Other Mechanics/Important Terminology

There are also a bunch of other mechanics not exclusive to one game, such as outside system skills. This section will cover all of the mechanics not limited to a game, as well as other important terminology inside of a virtual/augmented space.

Switch: Switching allows a fellow party member to take the lead spot against an opponent at any time. Most monsters and bosses have a short down-time in between attacks, so switching during the gap allows an additional blow to be dealt when a monster is stunned. Additionally, the AI algorithms are known to run slower when a change of attack style (which occurs during a switch), so monsters have marginally slower reaction times immediately after a «Switch». Kirito mentions that «Switch» is one of the skills that are improvised by players without the assist of the system, also dubbed by Kirito as "a skill outside the system" (Outside System Skill).

Outside System Skill: An ability, usually referred to as a skill, that either involves unconventional use of system-controlled skills, the exploitation of loopholes in the system, or the use of the player's human abilities to enhance their gameplay. Although such abilities are referred to as "skills", none are regulated by the system, though some involve making use of system skills in ways that were not intended by the developers of the game. These skills are developed through a player's capability in game and are acquired through experience and practice put in by the player themselves throughout playing time.

The Seed/World Seed and the Seed Nexus: The Seed is a free, preset series of program packages that can be used for creating Virtual Reality (VR) worlds as well as control the input and output of the five senses of the players, allowing players to FullDive into the created world. The Seed was created by Kayaba Akihiko and replaced usual proprietary game systems, like the Cardinal System that Akihiko had developed while working for Argus and which was required to run VR games, but had a terrifyingly huge license fee.

«The Seed» includes the basic programs needed to create a VR world, such as the audio and video system, as well as a downsized version of the Cardinal System, which was used in Sword Art Online to help in the development and to maintain control of the game. It is made so that the created VR world does not require one large server like the original SAO, but can run on multiple smaller servers.

All games using The Seed as their game engine allow conversion of one account in a Seed-based VR world to another. For example, this ability was used by Kirito when he converted his account from ALfheim Online to Gun Gale Online and back. It allows a player to transfer their data to another game and keep their stats instead of having to start from scratch, but all items and money from the previous game will be lost unless they are given to another player or put in an item storage for safekeeping before the transfer. The whole interconnected network of VR worlds is known as The Seed Nexus.

Artificial Intelligence: There are two types of artificial intelligence in the Sword Art Online Universe: Top-Down AIs and Bottom-Up AIs.

  • Top-Down AI: A Top-Down AI refers to artificial intelligence built from a program atop an existing computer architecture. NPCs in SAO have top-down AI, meaning they are scripted to act in an exact certain way in response to a very specific stimulus. Top-Down AIs work from an answer, and wait to respond to a question. Some AI can even be scripted and modeled to mimic human behavior, to almost be indistinguishable from a human. These AI simply have more data to process, and have learned to mimic behavior, to fit a personality. Yui is a prime example of a very advanced Top-Down AI.
  • Bottom-Up AI: Bottom-Up AI are AI that work in the opposite manner of a Top-Down AI, as they compute an answer when a question is given, rather than having a preset answer to a desired question. Unlike Top-Down AI, who learn by the "Ask A, so answer with B" method, Bottom-Up AI learn through "Learn B, and answer when asked A". According to Kirito, this is what a true artificial intelligence should be like. In the Sword Art Online Universe, the only known way to create a Bottom-Up AI is through the cloning of a human Fluctlight - creating an Artificial Fluctlight. An Artificial Fluctlight is the cloned quantum field (soul) of a newborn baby, which is later nurtured in a VR world. The definition of a Fluctlight is in the Real Life section.

Incarnation: Incarnation refers to a secretive art within the Underworld which enables an individual or group to alter the state of the world through imagination and will. It is a skill passed down to Integrity Knights since ancient times. However, this skill has always been integral to the Sword Art Online franchise to represent the theme of fighting for what's important; engraving itself even all the way back to the original Aincrad as a "power beyond the system".

Real Life

Though the Sword Art Online series focuses more on virtual reality than actual reality, there is still important technology and concepts in the real world that allows the virtual reality/augmented reality games to even exist.

FullDive: A FullDive is the act of linking to a virtual reality. It is the basis of most of the stories in the entire Sword Art Online series. To FullDive, a user must use a FullDive machine.

NerveGear: A 2nd generation FullDive machine that was created by Argus. It only has a single interface that covers a player's whole head and face. It completely controls the player's consciousness by redirecting the signals the brain sends to the body and sending its own waves to stimulate the five senses. It has its own battery source, as well as a high frequency electromagnetic microwaves transmitter. Puzzles, education related games, or environmental type games were first produced for NerveGear. Therefore, Sword Art Online was a major excitement to all gamers. This design trapped 10,000 players during the official launch of Sword Art Online in November 2022. It is the first VR technology that has been mass-produced.

AmuSphere: A 2nd generation FullDive machine, which was co-developed by RECT Progress Inc. The system has been modified to make it safer than its predecessor by changing the microwave transmitter to a low frequency one. The AmuSphere's design incorporates various sensors that continually monitor blood pressure and brain waves and provoke a safety logout feature in case that the person's status becomes abnormal. In addition, the AmuSphere does not completely block out signals from the body, like NerveGear did, so some players may pay extra for specialized rooms designed to make the experience in the virtual world more real by excluding the sounds and sensations from the outside.

Medicuboid: A 3rd generation FullDive machine developed for use in the medical field, instead of the entertainment industry. The basic design of the machine was provided by Koujiro Rinko, based on the machine that Kayaba used to copy his memories and thoughts onto the Internet. Unlike the 2nd generation devices that only consist of a helmet that connects to the user's brain, the Medicuboid is integrated with a bed, from the head to the spinal cord, rather than just a helmet and it connects not only to the medulla, but to the spinal cord as well. It also possesses a greater processing power, allowing interaction with deeper parts of the brain. All these improvements provide the user with enhanced reflexes and reaction time. However, this machine is only meant to be used for medical purposes, and specifically for patients in Terminal Care. The users of the Medicuboid hardly use their own bodies to come back to the real world; instead, they connect to external devices, like cameras and microphones, via the Medicuboid to interact with the real world.

The Augma: A next-generation wearable multi-device developed by Professor Shigemura Tetsuhiro and distributed by an emerging information and communication technology (ICT) company named Kamura. Unlike its predecessors, the «NerveGear» and «AmuSphere», the Augma is capable of sending signals to the brain while the users are awake, and is thus primarily used as an Augmented Reality (AR) device. Unbeknownst to the general public, the Augma also has the capability of immersing the user in FullDive due to the device being based on the NerveGear, however, this function is suppressed by default, requiring someone with knowledge of the feature to unlock it in order for it to be usable.

The Soul Translator: A 4th generation FullDive machine, invented by Higa Takeru at Rath. Unlike its predecessors, this machine does not connect to the users brain, but the user's Fluctlight (i.e. soul or consciousness) instead. The machine was created to be used in Project Alicization to create a highly adaptive Artificial Intelligence by copying a human's Fluctlight. The machine also has a function called Fluctlight Acceleration (FLA), which allows the machine to accelerate the user's «Thought Clock Control Signal», thus accelerating the user's sense of time by up to 5,000 times that of the time flow in the real world (However, there an issue arises with the use of such a high Fluctlight Acceleration rate. The Fluctlight has a limited lifespan of its own, estimated to be around 150 years, due to the accumulation of light particle usage for memories. Therefore, when a real human is FullDiving via the Soul Translator, the FLA rate is set to no more than 1,500 for safety measures, while human user is not recommended to spend more than thirty years in accelerated state). Additionally, the virtual world rendered by the Soul Translator is astoundingly lifelike, as the machine renders the world via memories, instead of polygons, meaning that every object in the virtual world is at the same level as the real thing in the user's consciousness.

  • Fluctlight: According to the «Quantum Brain Dynamics» theory in the Sword Art Online universe, an «Evanescent Photon» — a light particle that acts as a quantum unit of the mind — exists within the microtubules of a nerve cell. The light particle exists in a state of indeterminism and fluctuates according to the probability theory. A collection of these particles — a «Quantum Field» which Rath has dubbed a «Fluctuating Light» (abbreviated as «Fluctlight») — is what comprises the human consciousness, or the human soul.

Brain Implant Chip: A 4th generation FullDive machine was said to be under research at Santa Clara University. Kazuto believed that this research is the real successor of FullDive Technology, instead of the STL, which he thought was too complicated to be downsized for commercial use. The Brain Implant Chip has appeared in Accel World.

Old Aincrad's Power Scale

Because Sword Art Online is a game that spans over 100 floors, there are power gaps between floors. Here is the general level of AP per floor:

Note: It takes around 4-5 Floors for matches to be stomps, as seen with Floor 3 Kirito and Asuna vs the Floor 7 Elite Forest Elf, where Kirito and Asuna needed help from another Floor 7 Elite NPC to even stand a chance, and even then the battle was extremely difficult. Even with an entire party of 6 people, players cannot take the Elite NPC down without the ally Elite NPC either helping them kill the enemy, or by sacrificing themselves in a murder-suicide. This means that stats could be much higher than what is posted here.

  • Floor 1: 9-C to 9-B (SAO players have been shown feats higher than the average human, even at level 1. Can fight boars and wolves. Ilfang would cause at least Wall level damage through sheer size alone)
  • Floors 2-24: 9-A (Via the boulder feat and the Floor 2 bosses being this big)
  • Floors 25-55: 8-C (The boss on Floor 25 is massively stronger than all the previous bosses. Completely destroyed the Aincrad Liberation Squad, an entire Guild that had one of the highest member counts at the time)
  • Floors 56-99: High 8-C (GeoCrawler's width is the size of a one story house and its length is many times that of a one story house. Keep in mind that Floor 75 and above could be even higher, considering the Skull Reaper, the Floor 75 boss, was able to one shot players)
  • Floor 100: 8-B (An Incarnation of the Radius has shown feats on this level)

Power of the Verse

Sword Art Online is currently a verse that is, on average, in the Supersonic/Hypersonic and Building level range, however the later arcs boost the series by a large margin. The verse features regular humans with virtual avatars that are well into said Building level and Supersonic/Hypersonic range, with the key differences being each avatar a person uses.

Old Aincrad for instance has the top players well into Large Building level and it is where the strongest fighters are at their peak. ALfheim and New Aincrad show avatars roughly on the same level, if not slightly weaker, as Old Aincrad, but with the addition of flight and magic. Gun Gale has guns, both plasma-based and guns found in real life, as well as monsters comparable to Old and New Aincrad. Ordinal Scale shows avatars that far exceed Old Aincrad's Building level stats, reaching into City Block levels of power, however their augmented reality counterparts are just as strong as a regular human on average. And finally, the Underworld, which is roughly below Old Aincrad in physical strength but features far more powerful abilities with the introduction of Incarnation, Sacred Arts, and Release Recollection.







SAO Players

Aincrad NPCs


ALfheim Players

Ggo logo

GGO Players

Sao ordinal scale

Ordinal Scale Players

Alicization logo





The main theme of the Sword Art Online franchise, and the lemotif used for most of the series' main songs.

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