Glory kill

Glory kills are exceptionally violent, gruesome deaths which the Doom marine is capable of inflicting upon monsters and other players in the Doom. The most common type of glory kill occurs when monsters or players take a critical amount of damage or are otherwise stunned by special attacks; they will be highlighted by the Praetor suit's dynamic HUD as being vulnerable to direct attack. Closing to melee range at the proper angle and executing the correct attack will then engage the player directly with the target and execute one of many fatal attacks. Each monster species has several possible glory kills that can be performed against it. A short period of invulnerability is invoked during the beginning of most glory kills, but this does not last through the entire animation in most cases, making the execution of glory kills a matter of careful timing when in the heat of battle.

Other classes of attacks which may be considered glory kills (unknown at the present time) include kills with the chainsaw and the berserk power-up, both of which are similarly gruesome and frequently capable of taking out even extremely powerful enemies in a single deft blow.

In the single player campaign, glory kills are known to increase the amount of health and ammunition dropped from monsters. They are also the subject of many achievements and are required to be executed in order to accomplish goals in some of the game's upgrade paths.

Trivia
Comments made by id Software and Bethesda in the run-up to and aftermath of in 2014 suggested that this feature was inspired both by the popularity of Brutal Doom and the insane violence of the Doom comic.