Blood is the health of the Player. Upon spawning, a player will have 12000 blood. Getting hit by Zombies, being shot by other players, getting sick, ejecting from moving vehicles and falling from high places will decrease the player's blood. If the player's blood level reach 0, the player will die.
As a player's blood level decreases, color saturation decreases proportionally. Complete saturation loss usually occurs around 4000 to 3000 blood. At this point a player will occasionally shake, and the player character's heartbeat may be heard by the player. Hearing becomes impaired as blood loss increases as well. At less than 3000 blood, the player will start to randomly fall unconscious.
Regaining blood can be accomplished in a number of ways: