Invulnerability



The invulnerability is a powerup that makes the player generally impervious to damage for 30 seconds. It does not protect the player from telefrags, and is disabled in some areas. The powerup looks like a green sphere with a grinning head inside (resembling the Lost Soul from the Doom Alphas). While it is active, the colors in the player's display change to inverse monochrome, and the eyes of the status bar face glow yellow, making them look similar to the Demon's; in the last few seconds the display will begin blinking back to its original colors.

Invulnerability can also be activated with the cheat code idbeholdv.

In deathmatch mode of vanilla Doom, invulnerabilities and blur artifacts never respawn. Some source ports allow flags to be set to cause them to respawn.

Invulnerabilities are included in the items percentage displayed at the end of each level.

Appearance statistics
The IWADs contain the following numbers of invulnerability artifacts:

Trivia

 * The evil grinning face inside the sphere appears to be derived from the sprite of the Lost Soul from the Doom press release beta. Oddly enough, the invulnerability sphere in that version of the game was invisible and had an unused sprite in the IWAD which looked like a giant version of the Health bonus.