Domination is an achievement in Halo: The Master Chief Collection. It is unlocked by earning a total of 100 Legendary medals in multiplayer matchmaking. The achievement is worth 10 Gamerscore.
There are six Legendary medals: Extermination, Killionaire, Perfection, Steaktacular, Triple Double, and Unfriggenbelievable. They can be found on the top line of the player's in-game Medal Chest.