MLRS refers to the Multiple Launch Rocket System in Rust, Facepunch Studios' multiplayer survival game. The sound became familiar through raid videos, PvP clips and short-form edits where players use it to signal incoming destruction or instant panic. Because the barrage is so recognizable to Rust players, it spread beyond pure gameplay and now appears in meme edits as a danger cue, much like a danger alarm sound effect meme. Its staying power comes from how quickly it tells viewers that a situation is about to get much worse.