The six difficulty levels in the Call of Duty: Infinite Warfare Campaign are Recruit, Regular, Hardened, Veteran, Specialist, and #YOLO.
Completing the Campaign in any difficulty unlocks the Specialist difficulty level, and completing the Campaign in Specialist difficulty unlocks the #YOLO difficulty level.
The Specialist difficulty is meant to be as realistic as possible in terms of the damage inflicted on you and your enemies. For example, you will lose your helmet if it is destroyed by enemy fire, causing you to instantly die while in space or from a single headshot. You will also lose the ability to control your arms if you are damaged by an enemy, making aiming down sights incredibly difficult while losing the ability to use Tactical and Lethal equipment. However, you can heal yourself by using nano-shots and helmets located throughout the Campaign levels.
The #YOLO difficulty is very similar to Specialist difficulty, with the key difference being that if you die, you will have to start the entire Campaign over.
