Assault is a Campaign achievement for Halo 3 and Halo: The Master Chief Collection.
It is obtained when one completes the campaign mission The Storm on the Normal, Heroic, or Legendary Difficulty. In Halo: The Master Chief Collection, it is possible to get this achievement on Easy.
The Halo 3 achievement gives 30 gamerpoints to the player and is represented by a blue plate with a Roman numeral IV on it, which stands for four, as the level is the fourth playable level in Halo 3.
Note: The player must finish the level completely, beginning from Mission Start, or they will not get the achievement.