.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 still continues through manga, anime, video games, and novelty items or costumes.
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 FMDs (Face-mounted display) and Dreamcast-like controllers. It is the creation of German programmer Harald Hoerwick, who creates the first version, "Fragment", to help create his virtua 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 things. Most keyword combinations result in an Area with a field and a dungeon.
Each area features a large boundless expanse of terrain of finite size characterized by its open-air environment and lack of living civilization. Typically most structures in the fields are the ruins of some long ancient dwellings, or the bones of some massive creature. They contain dungeons, which are labyrinths containing two to five descending levels of interconnected rooms. It contains a single entrance/exit that links the first level to the field and a single stairway between levels. The deepest level of the dungeon contains a special room known for the distinctive floating figure, known as a Gott Statue, behind a golden treasure chest.
Most characters in the .hack franchise are known only by their virtual avatars within The World. The character class chosen determines the base appearance to other players and the role that they can play during combat. Because skills and abilities are given by the items equipped, each character class can only use a specific type of weapon, though some armors can be used by multiple classes. However, some character classes are chosen only as a matter of aesthetic value, reflecting the user's self-image whether real or ideal. In the beginning, there are only six types of classes: Twin Blade, Heavy Blade, Blademaster, Wavemaster, Heavy Axeman, and Long Arm. In .hack//Legend of the Twilight, an expansion to The World was released, introducing the Kickboxer and Werewolf class.
In the real world, Pluto's Kiss, a virus written by a ten-year-old elementary school student, 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.
Data Drain is an illegal skill that is used by various characters in the franchise. It rewrites data and has the ability to affect people in real life, such as making them fall comatose. It is generally required to "Protect Break" victims before Data Draining them.