||This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. (July 2012)|
.hack (pronounced "dot-hack") is a Japanese multimedia franchise that encompasses two projects; Project .hack and .hack Conglomerate. Both projects were primarily created/developed by CyberConnect2, and published by Bandai. The series is mainly followed through the anime and video game installations, and has been adapted through manga, novels and other related media.
The series takes place mainly within The World, a fictional MMORPG published and maintained by the also fictional CyberConnect Corporation, known as the CC Corporation. Players interact with The World using virtual reality headsets called HMDs (Head-mounted display) and a gamepad. It is the creation of German programmer Harald Hoerwick, who created the first version, "Fragment", to help create his virtual daughter, Aura.
The World consists of a cluster of servers distributed around the world. When players log in, they materialize in the Root Town of the server they last used. Each server in The World has its own unique Root Town. They are the starting and ending point of any gaming session. In order to properly log out of the game, the player must be in a Root Town. Each Root Town has a Chaos Gate, a large revolving ring used to transport players to areas or other servers. To transport to an Area, a series of three keywords must be entered. These keywords determine such parameters as difficulty, terrain, and weather, amongst other habitat. Most keyword combinations result in a field and a dungeon.
Before the series began, Pluto's Kiss, a virus, caused a simultaneous crash of all computers and network control systems on the Internet that did not run on the ALTIMIT OS, which subsequently became the dominant operating system worldwide. The Twilight Incident, also known as Pluto Again, and the Second Network Crisis is the series of disasters depicted in the .hack//Games. It involves the massive blackout and system shutdown at Yokohama, which results in multiple car accidents, fires throughout the city, various other system malfunctions in other parts of Japan, and various players of The World ending up comatose. It is caused by the glitching Morganna System, though it is eventually resolved with the full awakening of Aura. Kazushi Watarai is held responsible, despite being hospitalized for the majority of the incident.
The World R:2
Due to a fire in CC Corporation headquarters a year following .hack//Legend of the Twilight, CC Corporation had made a new version of the game called The World Revision:2 or simply as "The World R:2". The World R:2 offers new locations and old ones that are hidden within the game, these locations are commonly known as the lost grounds. There are many character classes, new and old. PKing (player killing) has become very popular in The World R:2 and due to this uprising, a guild called "Moon Tree" has been created against PKing. The leader of Moon Tree, Zelkova, is an expert hacker and created a place for hackers called "Net Slums".
The World R:X
The World Revision:X (or simply as "The World R:X") is a new portable version of The World created three years after the world R:2 was made. The World's fictional in-game setting is set a thousand years after the original version.
- .hack//Legend of the Twilight
- Shugo, Rena, Mirielle, Hotaru, Ouka, Balmung, Sanjuro
Project .hack was the first project of the .hack series. It launched in 2002 with the PlayStation 2 game .hack//Infection and the anime series .hack//Sign. Project developers included Koichi Mashimo (Bee Train), Kazunori Ito (Catfish), and Yoshiyuki Sadamoto, (Gainax). Since then, Project .hack has spanned television, video games, manga, and novels. There are 4 original .hack games .hack//infection - .hack//mutation - .hack//outbreak - .hack//quarantine
.hack Conglomerate is the second and the current project of .hack by CyberConnect2 and various other companies. The companies include Victor Entertainment, Nippon Cultural Broadcasting, Bandai, TV Tokyo, Bee Train, and Kadokawa Shoten. It encompasses a series of three PlayStation 2 games called .hack//G.U., an anime series called .hack//Roots, prose, and manga.
- .hack//Sign, an anime series released under Project .hack. It revolves around the character Tsukasa and his inability to log out of The World.
- .hack//Liminality, a set of four DVD OVAs included with the games released under Project .hack. It follows the story of Mai Minase, Yuki Aihara, Kyoko Tohno, and ex-CyberConnect employee Junichiro Tokuoka as they attempt to find out what is causing the comas.
- .hack//Gift, a self-deprecating, tongue-in-cheek, OVA that was created as a "gift" for those who had bought and completed all four .hack video games. It was released under Project .hack. In Japan, it was available when the Data Flag on the memory card file in .hack//Quarantine was present, whereas the American version included Gift on the fourth Liminality DVD. It is predominantly a comedy that makes fun of everything that developed throughout the series, even the franchise's own shortcomings. Character designs are deliberately simplistic.
- .hack//Legend of the Twilight anime series released under Project .hack.. It features most of the same characters as the manga version, but with an alternative storyline. It was incorrectly called .hack//Dusk, among other names, in early fan-translated versions.
- .hack//Roots, an anime series released under the .hack Conglomerate project. It follows Haseo and his joining (and subsequent exploits with) the Twilight Brigade guild. It also shows his rise to power and how he becomes known as "The Terror of Death". Towards the end of the series we see the start of .hack.//G.U. This series is the last in the .hack anime series to be licensed by Bandai Entertainment. After Sora from .hack//sign gets data drained at the end of the series he loses part of his memory and later on becomes Haseo, but still maintains his Player killing skills.
- Online Jack, a set of anime clips in the news section of the .hack//G.U. games' fake internet. It tells the "real world" story of the mysterious "Doll Syndrome".
- .hack//G.U. Trilogy, a CGI video adaptation of the .hack//G.U. video games released under the .hack Conglomerate project.
- .hack//G.U. Returner, a short follow up video and the conclusion to .hack//Roots released under the .hack Conglomerate project. It tells the story about the characters of .hack//G.U. in one last adventure.
- .hack//Quantum, a three part OVA series from Kinema Citrus and the first in the anime series of .hack to be licensed by Funimation.
- .hack//The Movie, a CGI movie, announced in August 23, 2011. On January 21, 2012, it was launched in theaters throughout Japan.
- Thanatos Report, OVA in .hack//Versus unlocked after finishing Story Mode.
- .hack, a series of four PlayStation 2 games that follow the story of the .hackers, Kite and BlackRose, and their attempts to find out what caused the sudden coma of Kite's friend, Orca, and BlackRose's brother, Kazu. The four volumes, in sequence, are .hack//Infection, .hack//Mutation, .hack//Outbreak, and .hack//Quarantine.
- .hack//fragment, the first .hack ORPG (Online Role-Playing Game). It was released in only Japan, and the servers have since been closed, ending all official online gameplay.
- .hack//G.U. is a series of three video games (Vol. 1 Rebirth, Vol. 2 Reminisce, and Vol. 3 Redemption) released for the .hack Conglomerate project. It focuses on Haseo's search for a cure after his friend was attacked by a player known as Tri-edge, which led to his eventual involvement with Project G.U, and the mysterious AIDA who plague The World R:2. This latest series has proven greatly successful to the .hack franchise, with the recent release of .hack//G.U. Vol 3 in Japan selling over 100,000 copies in one day and becoming the number one game the week of its release in Japan.
- .hack//Link, a PSP game released under the .hack Conglomerate project. It was said to be the last game in the series. Contain characters from .hack and .hack//G.U. video games.
- .hack//Versus, a PS3 game released under the .hack Conglomerate project. This game is also the first .hack fighter game, which is bundled with the new film .hack//The Movie.
- .hack//Guilty Dragon, a game for Android and iOS, is exclusive for Japan. An English release has been confirmed, no dates at this time.
- Untitled .hack, a new game announced by Hiroshi Matsuyama entering into production. No platforms have been revealed as of February 2014. 
- .hack//AI buster, a novel released under Project .hack. It tells the story of Albireo and a prototype of the ultimate AI, Lycoris, and of how Orca and Balmung defeated "The One Sin" and became the Descendants of Fianna.
- .hack//AI buster 2, a collection of stories released under Project .hack. It involves the characters of AI Buster and Legend of the Twilight Bracelet: ".hack//2nd Character", ".hack//Wotan's Spear", ".hack//Kamui", ".hack//Rumor" and ".hack//Firefly". "Rumor" was previously released with the Rena Special Pack in Japan.
- .hack//Zero, a novel series released under Project .hack. It tells the story of a Long Arm named Carl, of what happened to Sora after he was trapped in The World by Morganna, and of Tsukasa's real life after being able to log out from The World.
- .hack//Another Birth, series of novelizations released under Project .hack. It retells the story of the .hack video games from BlackRose's point of view.
- .hack//Legend of the Twilight, a manga series released under Project .hack. It tells the story of two player characters Shugo and Rena, as they win a mysterious contest that earns them chibi character models of the legendary .hackers Kite and BlackRose (from the .hack PlayStation 2 games).
- .hack//Epitaph of Twilight, a novel series telling the story of Harald Hoerwick's niece, Lara Hoerwick, who finds herself trapped in an early version of The World.
- .hack//Cell, a novel released under the .hack Conglomerate project. It revolves around a female Edge Punisher called Midori who acts as a "professional victim", by letting people PK her for money. Also to have as much money as possible
- .hack//GnU, a humorous manga series released under the .hack Conglomerate project. It revolves around a male Blade Brandier called Raid and the seventh division of the Moon Tree guild.
- .hack//Alcor, a manga series released under the .hack Conglomerate project. It focuses on a girl called Nanase, who appears to be quite fond of Silabus, as well as Alkaid during her days as empress of the Demon Palace.
- .hack//G.U.+, a manga adaptation of the three .hack//G.U. video games released under the .hack Conglomerate project.
- .hack//G.U. A Novel Adaptation of the three .hack//G.U. Video games released under the .hack Conglomerate project.
- .hack//4koma, a manga series which throws a little humor into both .hack and .hack//G.U. alike.
- .hack//Link, a manga released under the .hack Conglomerate project. It occurs three years after the end of .hack//G.U. in a new version of The World called The World R:X. It focuses on a player named Tokio and a mysterious exchange student named Saika.
- .hack//XXXX (read as "X-Fourth"), a manga series released under the .hack Conglomerate project. The manga adapts the four original .hack video games.
- .hack//Bullet, a web novel that follows Flugel after the events of .hack//Link.
- .hack//Enemy, a collectible card game created by Decipher Inc. based on the .hack series. It was discontinued after running five separate expansions between 2003-2005.
- .hack//G.U.The Card Battle is a trading card game similar to that of .hack//Enemy released under the .hack Conglomerate project. Unlike .hack//Enemy, the game was made by the original creators of .hack//G.U.. There are two sets of rules, one based on the mini game in the G.U. series, Crimson VS, and the one specifically designed for the trading card game.
- .hack// - Official (Worldwide)
- .hack// - Official (Japanese)
- Project .hack// - Official (Japanese)
- .hack// Conglomerate - Official (Japanese)
- .hack//Trilogy - Official (Japanese)