Mass Effect 3 Guide

This page contains a walkthrough for the main missions of Mass Effect 3. Major changes in the gameplay from Mass Effect are listed in the main Mass Effect 3 page, while the effects of importing a saved game from Mass Effect 2 are listed in the Save File Transfer page.

Main Plot
The following missions represent plot progression. Typically they have no time limit, and you can pursue side quests while they are available. Exceptions will be noted.
 * Prologue: Earth - Get to the Normandy before the Reapers kill you.
 * Priority: Mars - Save Liara T'Soni from Cerberus and find the Crucible, a weapon capable of stopping the Reapers.
 * Priority: The Citadel I - Begin rallying the other sentient races of the galaxy to the cause.
 * Priority: Eden Prime - (This mission is acquired by downloading the From Ashes DLC) Cerberus has discovered a Prothean artifact on Eden Prime. Land on the planet to recover the artifact.
 * Priority: Palaven - Help Garrus Vakarian rescue the turian primarch in the hopes that he (the primarch) will commit to your cause.
 * Annos Basin: Meet with Diplomats - Success. The turians will help Earth... but only if the krogan help them.  The krogan will help the turians... but only if they get their hands on Eve, the key to curing the genophage, currently imprisoned on...
 * Priority: Sur'Kesh - the salarian homeworld. Exfiltrate her with the help of old friends and the opposition of Cerberus.
 * Priority: Tuchanka - cure the genophage... or not. Starting this mission turns the Citadel into a mission zone, precluding shopping and sidequest completion, so keep that in mind.
 * Priority: The Citadel II - watch the political reaction to your decision, and help Ashley Williams or Kaidan Alenko deal with it. Or not.
 * Priority: Perseus Veil - in light of the previous missions, the quarians are willing to play ball... but first they need help in their war against the geth, who have allied with the Reapers in self-defense.
 * Priority: Geth Dreadnought - Attempting to destroy the geth flagship has put the entire Migrant Fleet at risk. Help Tali'Zorah vas Normandy infiltrate and destroy the ship before the quarians are annihilated.
 * Priority: Rannoch - the quarians are going home. The geth want to stop them.  Decide who should win.
 * Priority: The Citadel III - the asari councilor comes forward with information that the "Catalyst," a key component of the Crucible, might be on her home planet.
 * Priority: Thessia - Get that information.
 * Priority: Horizon - Cerberus acquires it despite your best efforts. However tracking their operative leads to here, which following this up will lead to..
 * Priority: Cerberus Headquarters - their main base. Starting this mission turns the Citadel into a mission zone, precluding shopping and sidequest completion, so keep that in mind.
 * Priority: Earth - You have the Crucible. You have the Catalyst.  Finish the fight.

Side Missions
These missions are issued or found as the game progresses. We have sorted them according to the Priority mission that makes them available, but because there are so many of them, the list may be incomplete or inaccurate.

Priority: The Citadel 1

 * N7: Cerberus Lab
 * Shrike Abyssal: Prothean Obelisk

Priority: Palaven

 * EDI Is Offline (unlocks EDI as a squad member)
 * Kite's Nest: Pillars of Strength (Refugee camp)
 * Citadel: Hanar Diplomat (Embassies, Kasumi Goto-centric side mission)
 * Benning: Evidence (Embassies)
 * Citadel: Improved Power Grid (Purgatory)
 * Apien Crest: Banner of the First Regiment (Purgatory)
 * Aria: Blood Pack, Aria: Blue Suns, Aria: Eclipse (Purgatory)
 * Citadel: Alien Medi-Gel Formula (Huerta Memorial)
 * Citadel: Biotic Amp Interfaces (Huerta Memorial)
 * Ismar Frontier: Prototype Components (Huerta Memorial)
 * Citadel: Barla Von (Liara, Presidium Commons)
 * Citadel: Heating Unit Stabilizers (Presidium Commons)
 * Grissom Academy: Emergency Evacuation (Jack-centric side mission)
 * Irune: Book of Plenix (Volus, Presidium Commons)

Priority: Sur'Kesh

 * N7: Cerberus Attack
 * Tuchanka: Turian Platoon
 * Tuchanka: Bomb
 * N7: Cerberus Abductions
 * Attican Traverse: Krogan Team (Grunt-centric side mission)
 * Citadel: Krogan Dying Message
 * N7: Cerberus Abductions

Priority: Tuchanka

 * N7: Cerberus Fighter Base

Priority: The Citadel II

 * Arrae: Ex-Cerberus Scientists (Jacob Taylor-centric side mission)
 * Kallini: Ardat-Yakshi Monastery (Samara- / Morinth-centric side mission)
 * Citadel: Asari Widow
 * Athena Nebula: Hesperia-Period Statue
 * Citadel: Batarian Codes
 * Citadel: Cerberus Ciphers
 * Citadel: Kakliosaur Fossil
 * Citadel: Medical Supplies
 * Citadel: Reaper Code Fragments
 * Citadel: Target Jamming Technology
 * Hades Nexus: Obelisk of Karza
 * Hades Nexus: Prothean Sphere
 * Silean Nebula: Rings of Alune
 * Valhallan Threshold: Prothean Data Drives

Priority: Geth Dreadnought

 * Rannoch: Admiral Koris, Rannoch: Geth Fighter Squadrons - One of these missions must be completed before Priority: Rannoch becomes available.