Team Fortress 2, released by Valve in 2007, is built around short class voice lines that players spam for comedy and quick communication, and this ready check joined that rotation on soundboards and in edits. Its meaning is instantly clear even outside the game, so creators pair it with similar quick callouts like enemy spotted, a flat nope, or an okay let's go before a push. That brevity has kept it useful long after launch, as a one-line agreement that needs no setup or explanation.