Halo: The Master Chief Collection

The description of the achievement speaks for itself. Load a Custom Game on the Bloodline map with one other player. When the match begins, both players must pick up a sniper rifle on top of their home base. After receiving the weapon, make an agreement and meet somewhere. One player needs to take aim with a sniper rifle using a telescopic sight, and the second needs to kill the enemy with a quick headshot and thus unlock the achievement. When the second player recovers, switch roles. Keep in mind that you need to kill a player who is using the scope of a sniper or beam rifle, and not any other weapon.