.hack//frägment

hack simulates an MMORPG; players assume the role of a participant in a fictional game called The World. The player controls the on-screen player character Kite from a third-person perspective but first-person mode is available. The player manually controls the viewing perspective using the game controller. Within the fictional game, players explore monster-infested fields and dungeons, and "Root Towns" that are free of combat.

They can also log off from The World and return to a computer desktop interface which includes in-game e-mail, news, message boards, and desktop and background music customization options. The player may save the game to a memory card both from the desktop and within The World at a Save Shop. A Data Flag appears on the save file after the player completes the game, allowing the transfer of all aspects of the player character and party members to the next game in the series.

hack games are set in an alternate history Earth, in the year 2010. After a computer virus called "Pluto's Kiss" crashes nearly every computer in the world, access to the Internet is closed to the general public to address security concerns. After two years without the Internet and online games, a MMORPG called The World is released. It becomes the most popular online game of all time with over 20 million unique players.

hack games, a number of users become comatose as a result of playing The World. However, the developers blame their condition on cyberterrorism.

hack began in early 2000 with the aim of shocking and surprising the player and creating a distinctive product. CyberConnect2's president Hiroshi Matsuyama played a key role in developing the concept for the series. A number of core ideas, including "slaying dragons or being a thief in London" were explored, but these were rejected in favor of an "offline/online game". Matsuyama said that this would give young gamers an opportunity to experience online play without paying monthly fees or needing powerful Internet connections.

The developers looked at a number of MMORPGs such as Phantasy Star Online, Ultima Online, and Final Fantasy XI for inspiration, and drew influences from the prior works of character designer Yoshiyuki Sadamoto (Neon Genesis Evangelion) and scenario writer Kazunori Itō (Ghost in the Shell). Itō noted that casting the player into the role of a subscriber of The World creates a unique story-telling situation which draws the player deeper into the plot.

By April 2004, the games had sold 1 million units in Japan and the United States. By March 2004, sales of the .hack games exceeded 1.73 million, with 780,000 copies sold in Japan.

Critics gave the series mixed reviews. .hack//Infection received the most positive reviews of the series; critics were intrigued by the games' unique premise. Jeremy Dunham of IGN was impressed by the game's commitment to preserve the illusion of online and praised the character designs and the inclusion of the Japanese voice track, but criticized the camera manipulation and the game's shortness and lack of difficulty. A Game Informer reviewer praised the way it captures the sense of community that a real MMORPG offers.