Three-Shot-Kill, or for a short acronym TSK or 3SK, is a term and phrase used in Halo: Combat Evolved referring to the number of perfect and faultless M6D Pistol shots it takes to kill a fully-shielded Elite Minor with a Sangheili Combat Harness, or a fully-shielded SPARTAN-II with Mjolnir Powered Assault Armor/Mark V. On Legendary difficulty, the three-shot-kill does not work on Special Operations or Zealot Elites. This is somewhat anachronistic in that it takes four shots from the Battle rifle of Halo 2 to kill opponents of the same type. Five shots to the head from the M6G will also kill a player, so nothing short of the Sniper Rifle has the same lethality as the M6D.