The Legend of 117

The Legend of 117 is an achievement in Halo 4 and Halo: The Master Chief Collection. It is awarded when the player completes the Campaign on Legendary difficulty. In Halo 4, the achievement is worth 70 Gamerscore and is represented by a shield in the background, with two crossed Lightrifles and a Promethean Knight skull. In Halo: The Master Chief Collection, the achievement is worth 20 Gamerscore, and is represented in the Steam icon by the well-known Elite skull in front of crossed swords and the difficulty shield, and concept art of the map Monolith in the Xbox art.

Obtaining this achievement in Halo 4 grants the player the full original MJOLNIR Powered Assault Armor/Mark VI suit for multiplayer.