Gib death occurs when, after a character has been damaged, its health is less than the negative of its spawn health (or original hit points). In other words, the character has suffered, in total, more than twice the damage needed to kill it in the normal fashion. For example, a zombieman having 1 hit point left (and which had an initial health of 20 hit points), would require an attack dealing 22 points or more of damage to be gibbed. An attack causing gibbing may also cause the monster's body to be thrown very far from its actual location of death.
The rocket launcher and the BFG9000 cause gibbing deaths very easily, although a second shot from the plasma gun can sometimes gib a zombieman that has survived the first shot. Getting telefragged also results in gib death, as it deals 10,000 damage.
Only seven characters in Doom have a "gibbing death" animation to denote a gib death: the player, zombieman, sergeant, chaingunner, Wolfenstein SS, imp, and nightmare imp. A single special death sound, DSSLOP (a squishing sound), is used for all of these. While the BFG9000 and telefragging can be used on other monsters to meet the above damage threshold, the normal death animation will still be used for any monster that does not have a gibbing animation. In the PlayStation port, the status bar face explodes when the player experiences a gibbing death, and in the 3DO port, it always explodes when the player dies.
An arch-vile can resurrect a gibbed corpse as though it were not gibbed, although the animation is different. If an arch-vile resurrects a gibbed Lost Soul, when it spawns, it will be invincible. This is a glitch that occurs in Ultimate Doom and Doom 2.
Doom 3 also features gibbing. However, only zombies and dead humans can be gibbed. This can work if the player constantly attacks corpses, or if they launch very powerful attacks (i.e. Shotgun blast at close range) to zombies.
In Heretic and Hexen, the threshold to to suffer a gib death is lower, set at half the health, rather than full health. For example a player is gibbed at -51 health and lower, instead of -101 health. The various player classes, as well as the gargoyle and weredragon for Heretic, and the affrit, ettin, centaur, chaos serpent (both green and brown), reiver and stalker, as well as Zedek, Traductus and Menelkir can all suffer gib death. In addition, if Corvus or Baratus is gibbed, his skull will fly into the air; when this happens, the camera detaches from the player's body and attaches to his skull, allowing him to see his own remains.
- Gibs is short for the English word giblets, or fowl innards. Adrian Carmack is credited with coining the term as applied to gaming, and Doom is one of the first games that gibs appeared in.
- Although the Cyberdemon only has a normal death animation, it bears much resemblance to an actual gibbing death animation (exploding into a bloody pulp).
- In the Game Boy Advance and SNES ports, gibs are notably missing and only the normal death animations are featured.
- In Doom 2 Beta, Arch-viles were able to raise Gibs into Lost Souls.