Exterminatus

Scince this will inevitably interest a lot of people.

Warhammer 40k
Within Warhammer 40k Extermnatus is the act of annihilating all life on a planet and is the last measure that is taken.

Novus Æterno
Within Novus aeterno it is planned that it will be possible for a player to nuke an enemy planet and with that destroy anything.

It should be noted that this should be used sparringly as it will not only make other people angry but also your own people.