Silent But Deadly

Silent But Deadly (Silent but Deadly in The Master Chief Collection) is an achievement in the Halo 2 for Windows Vista and Halo: The Master Chief Collection. It is awarded for killing 7 opponents from behind in a row without being spotted, on any Halo 2 campaign level, on any difficulty.

In the PC game it is worth 20 Gamerscore and is represented by a 16-pointed star, a green fireball on the star, and the face of a ninja on the top. In The Master Chief Collection it is only worth 10 Gamerscore and is represented by a screenshot of Tartarus and Miranda Keyes in the Installation 05 Control Room.

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The achievement is most easily unlocked on The Arbiter. Playing as the Arbiter, the player has the use of his active camouflage, which is extremely useful for avoiding detection. Additionally, the level is littered with sleeping Grunts just begging to be beaten down.

Despite the achievement's description, in the Master Chief Collection the player does not actually have to kill enemies with beat downs, but can utilize any weapon so long as the enemies remain unaware of the player's presence. As such, on Quarantine Zone, a player can utilize a glitch to get out of bounds on the Gondola and kill a group of at seven Flood combat forms with a rocket launcher. Another option presents itself near the end of Delta Halo where the player can use the Sniper Rifle to take out the Jackals, Elites and Grunts patrolling the temple, though this only works on lower difficulties, as Elites require two headshots on higher difficulties.