Health

A player’s health starts at a full 100 percent (or hit points). It may increase even beyond that from the effects of various powerups to as high as 200 percent (199 in versions prior to 1.2). It is decreased by environmental hazards (damaging floors, exploding barrels, and crushing ceilings), and successful enemy attacks. If a player's health ever drops to zero, that player dies.

The player's current health is shown on the status bar, both numerically, as a percentage of the character's full normal health, and graphically, by the condition of the character's face.

If a player that has armor is attacked, the armor will absorb some of the damage (one third or one half, depending on the type of armor) and thus lessen the decrease in health.

If a level ends while the player is dead, play proceeds to the next level, but with the player's status reset to that of a newly launched game (100 percent health, no armor, the pistol and 50 bullets).

Monster health
A starting player has a health of 100, and can increase it to 200. The armor effect is comparable to raising the health in 1/2, and the mega armor by doubling it. For example, a player with 200 of health and mega armor can withstand a total damage of 400.

Additionally, an exploding barrel has a health of 20, and Romero's head has 250.