Armor

The security armor (also known as green armor) is a powerup that appears as a green breastplate, similar to what is worn by the Doomguy. When collected, it increases the player's armor to 100%. It cannot be collected if the player already has at least 100% armor. When security armor is obtained, the game displays the message PICKED UP THE ARMOR.

Security armor will absorb one third of all damage received (rounded down) until it is fully depleted.

Security armor is not included in the items percentage displayed at the end of each level.

Appearance statistics
The IWADs contain the following numbers of security armor pickups:

Doom RPG
In Doom RPG, the security armor is called a flak jacket. It increases the player's armor rating by 25 units.