The cue comes from StarCraft, Blizzard Entertainment's real-time strategy game released in 1998, where the Terran Marine is the basic infantry unit produced from the Barracks. Its short ready and acknowledgement sounds were heard constantly during matches, so they became instantly recognisable to a generation of PC players. As StarCraft clips, remixes, and soundboards spread online, the Marine start sound escaped the game and became shorthand for spawning in, gearing up, or starting a mission, which is why creators still use it for gaming entrances today.