Should you rewrite or kill the Geth heretics in Mass Effect 2's A House Divided?

Every single one of the loyalty missions in Mass Effect 2 can have consequences that echo and reverberate into future games - which can make any choice agonizing. One mission does stick out as a particularly difficult choice, though: if you should rewrite or kill the Geth in Legion's loyalty mission, A House Divided.

Part of what makes the choice difficult is Legion itself. The artificially intelligent squad member is surprisingly pragmatic about the whole affair, and when the time comes to either destroy or absolve a bunch of its people, it doesn't seem to express much of an opinion either way. Compare this to other party members, who often have singular goals - Tali wants to avoid exile in her trial for treason, but without implicating her father. Kasumi clearly wants to keep the graybox. Anything other than that upsets them. Legion? Legion's a lot more chill. 

Another problem is in timing. If you're following something like our ME2 mission order page, which has the optimum mission order both for story and for obtaining the best ending, you'll recruit Legion and get its loyalty mission back-to-back right towards the end of the game. That means you've had less time to get to know it and the Geth - apart from as mortal enemies back in ME1. 

On this page, we explain the basic outcomes of the A House Divided loyalty mission for Legion, and explain what happens when you rewrite the Geth versus what happens when you kill the Geth. That way, you can at least make an informed decision - knowing the consequences both immediately, and into the next game.

Should you rewrite or kill the Geth heretics in Mass Effect 2's A House Divided?

After boarding the Geth Heretic space station and fighting your way through it, you'll eventually come to the point where Legion is interfacing with the ship and the Geth aboard it. While this is Legion's mission, your AI friend is unsure - it deletes the virus and then doesn't know what to do next. It asks Shepard for house, and expresses little opinion as to what it would prefer. In fact, in brutally honest robot fashion, it clearly doesn't have a preference at all.

As such, the choice is Shepard's. Which means it's yours. Now, you have to choose between options to Rewrite the Heretics or to Destroy the Heretics, essentially either brainwashing or killing a huge number of Geth. This is one of the game's choices with consequences in ME3. Here's what you can expect when you do each:

• If you Rewrite the Heretics, this is regarded as a Paragon option and as such is rewarded by giving Shepard many Paragon points. By bringing the Heretics into the broader Geth consensus, the Geth as a whole will be made stronger - which has consequences in ME3:
  • In ME3, the extra power of the Heretic Geth will increase the potential War Assets you can get from the Geth - they're raised by 450 Military Strength points in total. This value is used to determine the power of allied forces for ME3's final battle - so if you manage to get the Geth to join forces with you in that game (which is a big if), they'll be more powerful as a result of your choice here.
  • However, the Geth being more powerful means that when they come to blows with the Quarians in ME3, regardless of the overall otucome, the Quarian War Assets will be reduced by 150 points. 
• If you Destroy the Heretics, the base will self destruct once you depart it in a hurry. This basically will take down the majority of the Geth Heretic threat... and likewise, will have rolling consequences in the next game:
  • In ME3, destroying the Geth heretics has an inverse effect on the Quarian War assets - they're reduced by 150 overall. 
  • That means if you end up fighting alongside the Quarians in ME3's final battle, they will be overall weaker.
  • Meanwhile, the Quarian War Assets will be 150 more powerful than default. 

Regardless of what action you take at this point in the mission as far as rewriting or killing the Geth goes, Legion will be happy with the outcome and will become loyal. That loyalty can be reversed in a confrontation with Tali aboard the Normandy after the loyalty mission. Be sure to use a Charm/Paragon or Intimidate/Renegade dialogue option to resolve the dispute without anyone falling out with Shepard.

If Legion survives the ME2 suicide squad mission, it'll return in ME3 and will explain what happened with the Geth after these events, with the explanation differing slightly depending on what you did.