Just found it in my own game! Thanks though Suis3i!

NauticalSoup wrote:

The other quest line requires you destroy two hot planets (wat) before the academy occupation thing happens.  It's actually pretty ludicrous, since if I have enough tech and resources that I can afford to waste it researching planet destroyers, building them, and destroying totally arbitrary planets, I can probably just steamroll any remaining opposition anyway.  I think the Vodyani heretic quest line is my least favourite that I've encountered so far, and it DEFINITELY feels half-baked.  The lore justification for it is kind of insane, where you're supposed to be scrubbing the galaxy clean of Endless relics, and somehow that translates to blowing up exactly -two- planets, as long as they're also -warm-.

As others in this very thread have pointed out already, the planet cracker isn't super, it's pathetic.  "Joke weapon" would be a better way to describe it.  If you think this is adding value to your war efforts, you're clearly doing something terribly wrong - it's rare indeed to even require five terns of sieging + invasion against any star system that late in the game.

The thing that wins games is FIDSI, in particular, industry and science. The most effective way to ensure that someone has less FIDSI than you is to reduce the number or effectiveness of their systems. The best way to do the former is to conquer the system - but this is no guarantee you will keep it, especially if it's on the other side of the galaxy. *Sometimes* the most effective way to do both is to destroy their systems especially on larger galaxy sizes. I don't use planet crackers very often, but when I do it's usually because someone else on the other side of the galaxy is as close to winning as I am. Other than that, it's a fun thing to play with at the end of the game. Let's try not to say things like 'you're doing things terribly wrong'.  

WeLoveYou wrote:

Just found it in my own game! Thanks though Suis3i!

Haha no problem ! 

Bottom line is that the DEV's probably wouldn't have added the planet cracker module unless there was some sort of use for it in game. And as @WeLoveYou and @PotatoesAreBland point out, it's actually quite useful to blow up another empires planets, especially if you're competing with them for the victory or trying to secure an easy truce. Or you may want to create a sort of wall of uncolonizable systems to separate you and the "Cravers", or if you just want to play the bad guy and blow up all of the Sophons "Core Worlds". The list could go on. 

It is annoying to use, you cant mount weapons on the carrier, or fighters, and it does no damage durring combat,  and I found that you can usually invade and Conquer at that level and half the time it takes for the damn thing to charge.