Due to design decisions and or development limitations, video game corpses have a tendency to disappear after a short amount of time, if not immediately at life expiration. Loot, health or other rewards are typically left behind.
However, in certain games the corpse of an NPC or player character will remain in its death position without disappearing.
There is some flexibility in how long a body has to remain to be considered a Persistent Corpse; in some instances, bodies usually remain an indeterminate amount of time, vanishing only when you've left the area. Any corpse that doesn't vanish near-immediately or after looting may be an example of this concept.
This concept doesn't count gibs as persistent cadavers; a majority of the body should be present.
Persistent cadavers are commonly used within the Stealth genre, typically involving the hiding of a victim's corpse to prevent suspicion of foul play. Persistent cadavers are also a common feature of the RPG genre, generally for loot's sake, and the FPS genre - where the concept first materialized in Catacomb 3-D.