Thief: The Dark Project

Thief: The Dark Project, also known simply as Thief, is a 1998 first person stealth video game developed by Looking Glass Studios and published by Eidos Interactive. Set in a medieval steampunk metropolis called the City, the game follows Garrett, a master thief trained by a secret society. An expanded edition of the game, Thief Gold, was released in 1999.

Thief was the first PC stealth game to use light and sound as game mechanics. Its use of first-person perspective for non-confrontational gameplay challenged the first-person shooter market, which led the developers to call it a "first-person sneaker". The game combines complex artificial intelligence with simulation systems to allow for emergent gameplay. Thief's influence has been traced to later stealth titles such as Tom Clancy's Splinter Cell and Hitman.

The game received critical acclaim and has been placed on numerous hall-of-fame lists. With sales of half a million units by the year 2000, it is Looking Glass' most commercially successful game. Thief was followed by a series of three sequels: Thief II: The Metal Age (2000), Thief: Deadly Shadows (2004) and the reboot Thief (2014). Looking Glass closed after Thief II's release, and so the latter two games were developed by Ion Storm and Eidos Montreal, respectively.