The Arbiter (achievement)

The Arbiter is an achievement in Halo 2 for Windows Vista, and Halo: The Master Chief Collection. In the PC game, it is worth 30 Gamerscore and is unlocked by beating The Arbiter on Normal difficulty or above. In The Master Chief Collection it is only worth 10 Gamerscore, though it can also be unlocked on Easy.

In the PC game it is represented by the head of the Arbiter, Thel 'Vadam. In The Master Chief Collection it is represented by a screenshot of the Threshold gas mine.