Suicide exit

The death slide is a speedrunning technique in which the player deliberately kills off their character in order to pass through otherwise impassible obstacles to exit a level.

When killed by a weapon or by blast damage, an actor acquires momentum. Due to the counterintuitive motion exhibited by corpses in vanilla Doom, corpses can trigger walkover lindef types such as teleporters, crushers, and "trapdoor" exits. When the player is killed, their height is immediately reduced to the point that they are capable of sliding under walls or through windows that are normally impossible to circumvent that are at least 20 units in sector height. By combining these attributes, a speedrunner can perform a shortcut by killing themselves, via doing so with the rocket launcher while running backwards, or by allowing enemies to kill them while moving, resulting in them sliding through or under these obstacles and passing over the exit linedef, finishing the level early.

An example of this technique in action can be seen in the 00:09 NM speed demo of The Plutonia Experiment's MAP17: Compound by Vincent Catalaá, where it is used with the rocket launcher to pass underneath bars that otherwise must be raised by a yellow key switch to finish the level.