A 10GB patch will be waiting for players of Sniper Elite 3 on the Xbox One on the day of its release. Rebellion says that the patch is that massive due to issues with how Microsoft patches retail discs with digital download versions.
"The main part of the update is to sync data between the game's retail discs and the Xbox Live digital download edition of the game. In the several weeks between sending the code off to manufacture and release, rather than sit around or take a break, we've continued to work on the game, making improvements and optimisations.

"We've also begun work on multiplayer DLC and a small part of this update is to introduce a compatibility pack. This is standard for any game that adds DLC - it's just to make sure everyone can have the same multiplayer experience whether they own DLC or not.

"While we understand gamers will be frustrated at the wait, the good news is that the update will actually reduce the size of the game's total install footprint on their hard drive, and reduce the size of future patches significantly.

"It's part of this ongoing optimization process that's enabled Sniper Elite 3 to perform well at a native 1080p on both Xbox One and PS4. We appreciate everyone's patience and we firmly believe Sniper Elite 3 will be worth the wait!"

Oddly enough, this patch will also bring the install size of the game from 21GB down to 19GB. There will be patches for the PlayStation 4, PlayStation 3, and Xbox 360 versions but they will be much smaller than 10GB. Rebellion also noted that the 10GB patch only applies to the first run retail discs and those buying digitally or second run retail discs will not have this massive 10GB update.