Following the release of the Infinity’s Armory Update five weeks ago, 343 Industries has officially revealed the latest update coming to Halo 5: Guardians, the Hammer Storm Update, offering players a new set of content that's "guaranteed to get any Halo multiplayer fan’s pistons fired up!".
The Hammer Storm Update features:
New game modes including Grifball, Assault, and Fiesta
New map called Torque
New weapons including the Gravity Hammer and the Halo: CE Pistol
New REQ items including attachments for loadout weapons, weapon skins, armors, emblems, assassinations, visors, and stances
New game types in Forge mode
The Hammer Storm Update is now rolling out as a free update and will automatically download and install once you launch Halo 5: Guardian.