Dealing enough damage to an enemy may cause them to 'stagger' which is indicated by a blue highlight. When the player comes into close range, indicated in an orange highlight, the Doom Slayer can perform a special melee action which kills the enemy instantly in a spectacularly brutal fashion. While performing this kill, the player is invulnerable. It can be disadvantageous if used while under attack by a horde of enemies, however, making choosing whether or not to Glory Kill a tactical choice. In addition, enemies killed through Glory Kills always drop health pickups, making it a great way to recover health during pitched battles with hordes of demons.
Boss battles (the Cyberdemon, the Hell Guards and the Spider Mastermind) can only be finished with Glory Kills; failure to do so will result in the boss recovering a bit of its health and continuing the fight.
Berserk and Glory Kills
The Berserk powerup takes away your weapons when active, but greatly reduces your taken damage and allows you to instantly Glory Kill any non-boss enemy within melee range. When Berserk is active, you retain the full benefits of all Runes (see below) that affect Glory Kills.
The Chainsaw allows you to perform a special Glory Kill that allows you to recover your Ammo if you are running low. This kill is the only way (aside from Berserk) to Glory Kill a demon without staggering it first, and requires fuel for each kill, with larger monsters requiring more fuel to kill.
Runes Affecting Glory Kills
Certain Runes improve Glory Kill efficiency, make Glory Kills easier to perform in some way, or activate other effects upon performing a Glory Kill:
- Dazed and Confused allows you to stagger enemies for longer, granting more time for a Glory Kill.
- Seek and Destroy allows you to Glory Kill enemies from farther away.
- Savagery increases the speed at which you perform a Glory Kill.
- Armored Offensive gives you armor pickups for Glory Killing enemies.
- Blood Fueled gives you a speed boost for a short period upon a Glory Kill.
- Intimacy is Best gives staggered enemies damage resistance, making them more Glory Kill friendly.
Glory Kills in Multiplayer
In multiplayer, Glory Kill opportunities occur in random occurrences while dealing damage, usually when an enemy is at low health. Unlike Glory Kills in single player, the player is not granted brief invulnerability, and enemies who can have a Glory Kill performed on them don't stagger. If a player is performing a Glory Kill and is killed before executing the killing blow, the intended victim will survive. This applies to Glory Kills against demons, other players, and Baron, Cacodemon, Prowler, and Spectre Glory Kills.
A player performing a Glory Kill in multiplayer gets a "Glorious" award and 25 points.
- Lost Souls are the only enemies that cannot have a Glory Kill performed against them.
- Some enemies have varied Glory Kill animations based on where the player aims on the enemy before performing the kill, such as the leg sweep on a Hell Razer while looking at its right leg, or the infamous "Death From Above" requiring you to be in the air and above your enemy when executing the kill. Many Challenges will require you to execute these special Glory Kills on specific enemies.
- Glory Kills may have been inspired by a notably popular mod for the original Doom series called Brutal Doom, which included "Rip and Tear" mode, an alternate unarmed combat mode which could be accessed after grabbing a Berserk Pack, and which allowed you to perform Mortal Kombat-style fatalities on monsters.
- At least one Glory Kill was cut from the official game release or sped up - for example, a frontal glory kill on a Hell Knight, consisting of punching it in the head three times then snapping its neck, was removed.
- Only one Glory Kill in the entire game (aside from chainsaw kills) involves the use of a weapon, and that is the final kill of the Spider Mastermind, which involves the use of the BFG 9000.