The line comes from Half-Life, the 1998 first-person shooter set in the Black Mesa Research Facility, where a synthetic public-address voice delivers status updates and warnings to staff and soldiers. As players recorded and shared gameplay, short Vox announcements became popular soundboard clips because they sounded official, detached, and easy to drop into other videos. The phrase later spread through gaming edits, streams, and memes as a shorthand alert for combat starting. Its staying power comes from that instant recognition among players and its clean, short delivery, which fits reaction videos, montages, and jokes about unexpected confrontations.