Health system

As with all FPS games, the player has a health system in Call of Duty games.

In all games before Call of Duty 2, the player needed health kits that would heal the player when a kit was taken.

Starting with Call of Duty 2, health kits were gone, and were ditched in favor of a regenerative health system. When shot, no matter how many times (assuming the player isn't dead) it takes 5 seconds for all health to regenerate.