Overkill comes from Halo Reach, the 2010 Bungie shooter for Xbox 360, where longtime announcer Jeff Steitzer calls out multiplayer medals. The medal is awarded for killing four enemies in rapid succession, each within a few seconds of the last, making it rarer and more prestigious than a Double Kill or Triple Kill. As Halo clips were shared on YouTube and in montage culture, the callout escaped the game as shorthand for dominating a lobby, and its booming delivery still signals instant bragging rights for FPS players today.