Plot[ edit ] The Reapers invade and quickly overwhelm Earth. Shepard is reinstated by Anderson, who stays behind to rally resistance. Hackett orders Shepard to Mars,  where Shepard reconvenes with Liara. She has discovered blueprints to a Prothean superweapon that can destroy the Reapers. Cerberus and the Illusive Man intervene, revealing that they want to control the Reapers instead.
The Alliance begins construction on the superweapon, dubbed the "Crucible", but the Council refuses to help them, so Hackett orders Shepard to forge alliances by aiding other species in their own battles against the Reapers. Shepard begins by rescuing the turian primarch, Adrien Victus, from a moon orbiting the turian home world, Palaven.
The krogan leader, either Urdnot Wrex or Wreav, refuses until the genophage is cured. Shepard and the krogan leader travel to the salarian home world, Sur'Kesh,  where they rendezvous with an ally on the inside, Mordin Solus or Padok Wiks, along with a female krogan named Eve. After defeating Cerberus forces, they escape to the krogan home world, Tuchanka, where a plan is hatched to disperse the genophage cure using a tower called the "Shroud".
The salarian dalatrass, Linron, pledges salarian support if the sabotage is left in place. One outcome of the mission is that Shepard cures the genophage by allowing Mordin or Padok to deploy a counter-measure to the sabotage, sacrificing his life in the process.
Another outcome is that Shepard either kills the salarian ally or convinces him not to deploy the counter-measure, which deceives the krogan into lending their support while also earning the support of the salarians. Shepard then travels to the Perseus Veil, where the quarians are aiming to reclaim their homeworld, Rannoch, from the geth. As the quarians close in on defeating the geth, Shepard must either allow the geth to upgrade and annihilate the quarian flotilla, stop the upgrade and let the quarians vanquish the geth, or negotiate a ceasefire and gain support from both sides dependent on past decisions.
The asari councilor then informs Shepard of a Prothean artifact on their homeworld, Thessia, which may help Shepard identify the "Catalyst", an essential tool which can complete the Crucible. Seeking revenge, Shepard follows Leng to the human colony, Horizon, where Cerberus has been researching how to control the Reapers.
There, Shepard encounters Miranda Lawson if she survived the suicide mission , who gives Shepard her tracking device. Shepard assaults Cerberus headquarters; although the Illusive Man has already escaped, Shepard successfully recovers Vendetta and kills Leng.
Shepard learns that the Catalyst is in fact the Citadel itself, which the Reapers have captured after successfully indoctrinating the Illusive Man. Under Hackett, Anderson, and Shepard's leadership, the Alliance and its allies launch an all-out assault on the Reapers in a last-ditch effort to retake Earth and the Citadel via the Crucible.
After a long battle in a ruined London, Shepard determinedly makes it to the Citadel beam after being greatly wounded by Harbinger, the most powerful Reaper. The conflict ends in Anderson's death, after which Shepard is transported to the pinnacle of the Citadel. A childlike AI appears, proclaiming itself the Catalyst and the creator of the Reapers. It reveals that the Reapers harvest and preserve organics advanced by synthetics to allow more primitive species to evolve.
The activation results in Shepard's death and the mass relay network being destroyed. In a post-credits scene , an individual known as the "Stargazer" tells Shepard's story to a young boy, implying that Shepard's legacy lives on far into the future. Extended Cut[ edit ] The Extended Cut provides additional scenes and dialogue towards the end of the story. Shepard's squadmates are critically injured incinerated if EMS is low by Harbinger during the push to the Citadel beam, forcing Shepard to call in the Normandy to extract them.
Shepard can now refuse to activate the Crucible, leading to a Reaper victory and a fourth ending where the next cycle defeats the Reapers instead via knowledge from one of Liara's beacons.
The mass relays are now severely damaged instead of being destroyed by the Crucible's firing unless EMS is low. Shepard having low EMS and picking Destroy will result in the Crucible devastating the galaxy, implicitly killing the Normandy's crew and leaving a more pessimistic outlook for the future. However, if Shepard chooses Destroy with a high enough EMS, they will instead refuse and smile hopefully.
Development[ edit ] BioWare co-founders Ray Muzyka and Greg Zeschuk envisioned that Mass Effect 3 would be accessible to new and returning players alike. On April 20, Belgian website 4gamers. For the first time, fans were shown actual gameplay videos, including a 15 minute demo supervised by Casey Hudson. At Gamescon , a new trailer was released demonstrating 50 seconds of combat gameplay. In a response from Jesse Houston, it was revealed that the leak was the result of "human error" at Microsoft.
Houston stressed that the leaked code was in a rough, unfinished state not intended for public release. Despite BioWare's quick response, some fan videos still made their way to YouTube. From the beta, some information was extracted from game files that represented rough notes from early story drafts.
To promote Mass Effect 3, BioWare relied heavily on viral marketing. Using an internal channel called BioWare Pulse, weekly videos were posted on the company's official website and YouTube offering fans a preview of upcoming content. Alongside the regular edition, there was also a collector's edition and a digital deluxe edition, each of which included bonus content and unlockable items; most notably, four exclusive weapons found in the N7 Arsenal Pack.
Unlike the first two games in the series, BioWare specifically included the female version of Commander Shepard in marketing Mass Effect 3. The games were equipped with a GPS tracking device, allowing fans to track their progress.
When the balloons landed, anyone who found one was able to snag a copy of Mass Effect 3 a week or more ahead of its release. Customers purchasing PC editions of the game retail or digital are required to install Electronic Arts' content delivery and digital rights management system, Origin.
The Origin client and an Origin account is required to install, activate and run Mass Effect 3 on a PC for single and multi-player portions of the game.