Sentinel armor

Sentinel armor is an optional mechanic in Doom Eternal which provides an element of dynamic difficulty adjustment. If the player dies multiple times during a boss fight, they will be offered the chance to activate Sentinel armor to achieve a dramatic increase in defense against enemy attacks. When the player has Sentinel armor active, the corners of the screen have a slight green glow.

The availability of Sentinel armor can be toggled via gameplay options in the menu. The effects of Sentinel armor can be attained permanently while replaying levels via use of the "IDDQD" cheat code disk. Sentinel armor cannot be used on Ultra-Nightmare skill level, as a single death ends the game.

Bugs

 * In early versions of the game, the higher defense of Sentinel armor would sometimes be erroneously retained if returning to the campaign after using it in the mission select menu.
 * The Sentinel armor glow still appears during some third-person cutscenes.
 * Sentinel armor will never activate during the Dark Lord boss fight.