The Self-destruct is an integrated mechanism present in starships, UNSC bases and is used to cause a massive explosion to completely destroy itself in order to prevent vital navigational data and strategically-valuable information from falling into enemy Covenant clutches, as per paragraph five of the Cole Protocol.
 Halo: Combat Evolved
In the level The Maw, Cortana and the Master Chief were forced to activate the Pillar of Autumn's self-destruct sequence in an effort to prevent the Flood parasite from getting off of Installation 04, and particularly keeping 343 Guilty Spark from firing the Halo and wiping out all sentient life within three radii of the galaxy. Cortana and Master Chief's plan would have successfully worked had not Guilty Spark aborted the self-destruct sequence, and as Cortana was unable to reactivate the countdown, so the Chief proposed using explosives to cause the fusion reactors to go critical and explode, thereby destroying the ring.
 Halo 2
Cortana attempted to blow the engines of the UNSC In Amber Clad in an effort to stop the Flood and to keep the Covenant from firing Installation 05, but was kept from doing so when the Gravemind captured her.
 Halo: The Fall of Reach
The UNSC Remote Scanning Outpost Fermion was forced to enact paragraph five of the Cole Protocol and had to flood the station's reactors with deuterium, causing a critical overload in order to destroy the station's science library, which was offline for repairs.
 Midnight in the Heart of Midlothian
When the Destroyer UNSC The Heart of Midlothian was captured and boarded by the Covenant, the ship's AI, Mo Ye, told Sergeant Michael Baird to go to the bridge to reconnect Mo Ye to the rest of herself and the ship in order to enable the self-destruct and destroy the ship along with its data and all the Covenant aboard.
 List of appearances
- Halo: Combat Evolved (First appearance)
- Halo: The Fall of Reach
- Halo 2
- Halo Evolutions