BattleMech Self Destruct
An act of extreme desperation, the BattleMech Self Destruct Sequence is a method whereby a MechWarrior intentionally destroys the 'Mech they are piloting, generally as a way to cripple nearby enemies within in the radius of an engine explosion or as a "spoilsport" means of denying the enemy salvage.
Triggering a modern Fusion Engine to self destruct is a relatively complex procedure due to the large number of safety systems specifically designed to prevent them from exploding. Generally the pilot must selectively cripple these, often by crude methods such as when Kai Allard-Liao famously pulled the engine control circuits on Twycross to trigger hidden explosives and destroy the Falcon Guard  or by attempting to manually override the engine's safety systems.
Due to the rather hit or miss nature of these methods , the most common way of achieving the desired end-result is by using a Booby Trap, placing explosives within the 'Mech in such a way to ensure its engine explodes spectacularly.
- Under the Tactical Handbook rules, the controlling player must merely declare his intention to destroy one of the 'Mechs under his control during the Weapon Attack Phase of the current turn, and is unable to perform any other attack or movement in that turn. The 'Mech engine explodes in the next Weapons phase after the self-destruct sequence is declared. Once started the Tactical Handbook self-destruct sequence cannot be stopped, and follows that book's rules on BattleMech Engine Explosions. 
- Maximum Tech and Tactical Operations both use the same basic rules, with the notable change that the player wishing to destroy one of his 'Mechs must declare his intention, but not the 'Mech in question in that turn. The 'Mech in question is revealed during the Weapons Attack Phase of the next turn, and explodes during the End Phase, with the pilot able to attempt to eject during the Movement Phase rather than moving the unit. Unlike the automatic Tactical Handbook sequence, the version in both these books also requires the controlling player to make a successful unmodified Piloting Skill Roll to override the safety protocols to initiate the destruct. If it fails, the 'Mech does not explode and can perform no other action. However, as long as the pilot has not ejected, the roll can be re-attempted during subsequent Weapon attack Phases.  Tactical Operations also adds the extra rule that if the self-destructing 'Mech received the three critical hits that would normally destroy an engine any time during the self-destruct sequence, the 'Mech shuts down as per normal and does not explode, with four or more triggering a "normal" BattleMech Engine Explosion. 
- Blood of Kerensky Omnibus Epub, pp. 289-299 "Lost Destiny - Chapter Thirty-Six"
- Tactical Handbook, p. 45 "BattleMech Engine Explosions
- Maximum Tech, p. 20 "Engine Explosions - Self-Destruct Sequence"
- Tactical Operations, p. 78 "Engine Explosions - Self-Destruct Sequence"