By Remember the computer terminal on the main menu of the original Black Ops, which featured hidden mini-games and secrets once you'd broken out of that integration chair?
You can expect something similar in Black Ops 3. Inside the Safe House - a destination you visit between every story mission - is a PDV, or Personal Data Vault, you can access.
It's used to change Clan Tags, tweak emblems and play music, hiding a few Easter Eggs and mini-games, and home to intel files that flesh out the game's universe.
There are over 100 times as many files in the new computer terminal compared to Black Ops, which clues players in from the events of World at War through to Black Ops 3's futuristic 2065 setting.
"If you took all those pages of documents that we made [in Black Ops 1], and you brought them over into our new system, they would make up less than 1% of the total number of files we have in our new system," game director Jason Blundell told press including Digital Spy.
"I know, because we did that - we pulled all the files over, for those who might not have read them, they're in Black Ops 3 as well - but they're less than 1% on the files.
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"We had a writer work full time for a year and a half, whose only job was to write all this stuff. He wrote everything. Every country, decision, vehicle, weapon, everything is in there.
"There's pages and pages and pages of this stuff. Once you complete the campaign, we actually unlock even more pages for you. Tons."
The PDV sits inside a customisable bunk room that's unique to each player. Each personalised room will appear in the Safe House whenever a player loads into the game, allowing others to visit it between missions.
Collectables big and small found in the campaign can be placed on a shelf or adorned on a wall, and medals - think of them as mini-achievements - can also be displayed to show off a player's prowess.
Outside of each player's bunk room is a larger shared space where you can customise and build weapons, enter an 'Immersion Zone' to test load outs before a mission, and change your appearance and gender with a wardrobe.
When you're ready to get started, any of the game's campaign missions can be played from the get go - a new approach for a Call of Duty game.
"When you get a book, you can read the last page if you so wish. You can play the last level on this game, if you so wish. It's your content - you bought it. Who am I to get in the way?" Blundell explained.
"Because we've made this very systemic game, it'll support how you'll want to move through the content. It will give you a warning and say, by the way, you're going to ruin the story for yourself if you jump ahead.
"It's not unlocking - because we've so many other ways of rewarding and challenging the player, it's not about completing a level to experience the next level. You can freely move through that content."
Call of Duty: Black Ops 3 will be available on PS4, Xbox One and PC from November 6, and won't include the game's campaign mode.
Black Ops 3 everything you need to know, including trailers and Zombies mode
Watch a story trailer for Black Ops 3:
