Halo 5 will require a 9GB Day One Patch
Halo 5: Guardians Studio Head Josh Holmes recently announced via Twitter that a 9GB update will be required for the Xbox One shooter upon its release.
According to the tweet (and some replies), the patch directly pertains to multiplayer, and is not necessary for players to enjoy the game's campaign mode.
It was recently discovered that Halo 5: Guardians will require 60GB of free space on Xbox One hard drives for a disc install, meaning nearly 70GB will already be dedicated to the game upon launch. In comparison, Metal Gear Solid 5 requires 25GB of free hard drive space, CoD: Black Ops 3 will take up 45GB on current-gen consoles, and Fallout 4 will come with a 28GB install.
Also, last year's infamous Halo: Master Chief Collection retail edition required 65GB of free space, of which 20GB came from a day one patch; this was then followed by a slew of hefty updates to counter the numerous technical issues which plagued the collection's matchmaking system.
Halo 5: Guardians is set to release on Tuesday, October 27th, and was recently confirmed to have already gone gold.