The sound comes from Counter-Strike: Global Offensive, Valve's tactical shooter released in 2012. Weapon cases were added in the 2013 Arms Deal update, and the sharp unlock click became part of the ritual of opening them for rare skins. Clips of case openings spread widely on YouTube and Twitch, where the sound became shorthand for gambling-like anticipation alongside staples like the bomb has been planted callout. Editors now reuse the isolated click in montages and short-form content to signal any kind of reveal, even outside CSGO.