Garry's Mod, commonly clipped as GMod, is a 2006 sandbox game developed by Facepunch Studios and published by Valve.

Other game modes, notably Trouble in Terrorist Town and Prop Hunt, are created by other developers as mods and are installed separately, by means such as the Steam Workshop.

[4] The "tool gun" is a multi-purpose item for tasks such as welding and constraining props together, and altering the facial expressions of ragdolls.

[2] Garry's Mod includes the functionality to modify the game by developing scripts written in the Lua programming language.

[5] Notable mods (known as "addons") include Spacebuild, Wiremod, Elevator: Source, DarkRP, Prop Hunt, and Trouble in Terrorist Town.

[9] The winner of this contest was Trouble in Terrorist Town (TTT), which was added to the game in July 2010, alongside another mode, Dogfight: Arcade Assault.

[12][18] In July 2009, four developers working under the name "PixelTail Games" opened a Garry's Mod server called GMod Tower.

GMod Tower was a network of servers, designed as a social media platform for users to play minigames with friends and socialise in a hub area.

[21][22] YouTube user Djy1991 used Garry's Mod to animate the fan fiction, using literal interpretations of some of the work's typographical errors and awkward grammar.

The addons' new source files contained curses directed at Newman, Valve co-founder Gabe Newell, and Steam moderators.

[24][25] Facepunch Studios blacklists servers that are malicious, depict sexual violence, or contain content that is not safe for work but not marked as such.

In April 2023, following a Twitter poll with close to 50,000 respondents, the company additionally banned the glorification of Nazism, including the display of swastikas and the Nazi salute.

[26][27] In response to a takedown notice from Nintendo in April 2024, Facepunch Studios began removing Nintendo-related Steam Workshop entries.

[9] He stated that, at the time, his skills in computer programming were not advanced enough to create a full Source-based game and he resorted to the mod format.

[43][44] When Garry's Mod was moved over to Valve's SteamPipe content delivery system, completed on 5 June 2013, an experimental Linux client was also introduced.

[67] He later announced S&box, a sandbox game using Unreal Engine 4, in September 2017 as a potential spiritual successor to Garry's Mod.