Invulnerability can also be activated with the cheat code idbeholdv.
Invulnerabilities are included in the items percentage displayed at the end of each level.
According to the function P_DamageMobj in p_inter.c, invulnerability only protects the player from attacks doing less than 1000 points of damage; while no monster in the game can do nearly that much damage in one attack (a direct hit from the rocket of a Cyberdemon will inflict at most 288 damage), a telefrag inflicts 10000 points (and indeed will kill even an otherwise invulnerable player). This also means that DeHackEd can be used to circumvent the invulnerability powerup by creating incredibly powerful weapons.
- The grinning face inside the sphere appears to be derived from the Lost Soul sprite in Doom 0.4. 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 health bonus.
- Due to limitation of engine, the Invulnerability Artifact lights up all the areas in the game similar to the Light Amplification Visor. It would require a complete table of 32 shades for a proper effect.
- Interestingly, although a damaging floor of Type 11 will cancel the effect of the God mode cheat, the invulnerability artifact will remain active while the player is in such a sector until its proper duration has expired. This property of the artifact would theoretically allow players who obtain one using the idbeholdv cheat to buy enough time that they can clear out ending Type-11 rooms containing monsters, such as the one in Phobos Anomaly.
- Doom 4-2 Alpha at toastytech.com
- alt.games.doom post about creating weapons that can kill invulnerable players, via Google Groups
- rec.games.computer.doom.editing post about creating weapons that can kill invulnerable players, via Google Groups
|Items from classic Doom games|
Keycard • Skull key