Extra life

Extra Life is a power-up which is introduced in Doom Eternal.

Tactical analysis
Extra Life automatically activates when player's health reaches zero, working similarly to the Saving Throw rune of the previous game, giving the player a full health and a brief invincibility period as denoted by the grayscaled screen without restarting to the latest checkpoint.

Extra lives are marked on the map as the Doom Slayer helmet icons. Unlike most major collectibles, they respawn when replaying a mission.

In the Extra Life difficulty modifier, running out of Extra Lives will end the campaign, forcing the player to restart it from the beginning.