In ROS, TTK (Time To Kill) is incredibly low. A headshot from a Sniper or a burst from an AR will end you instantly. The "3-Second Rule" states: If you haven't killed them in three seconds, relocate.
The Rules of Survival: A Definitive Guide to Staying Alive in any Emergency Rules of Survival
Equip your M4, check your six, and stay out of the red zone. We'll see you at the helicopter extraction point. In ROS, TTK (Time To Kill) is incredibly low