Gameplay

Counter-Sniped

From Halopedia, the Halo wiki

Counter-Sniped is an achievement in Halo: The Master Chief Collection. It is unlocked by killing an enemy player in a Halo 2: Anniversary multiplayer match with a Sniper Rifle or a Beam Rifle while that player is zoomed in. The achievement is worth 10 Gamerscore and can be unlocked in both matchmaking and custom games.