Mass Effect 2 is an action role-playing game developed by BioWare Edmonton, with assistance from BioWare Montreal, and published by Electronic Arts. The game is the sequel to Mass Effect, and was released on Microsoft Windows and Xbox 360 in North America on January 26, 2010, with subsquent release dates in Australia for January 28, 2010 and in Europe for January 29, 2010.

A "Prelude to E3" developer diary was released on May 15, 2009. The developers confirmed that the combat system has been upgraded, with everything from the feel of the combat and the A.I. being improved, including realistic damage modeling and downed enemies still continuing to crawl and fight. New to the series is a heavy weapons system that will allow players to "kill [somebody] a thousand times" over. The tone of the game is similar to that of the Wild West, featuring warlords and crime gangs. The video also confirmed the existence of new alien races and an attack by one race on Citadel-controlled space, wearing armor with an "M1" logo painted on it and seeming to control similarly-armored varren, a race of non-sapient animals similar to dogs.^[7]

Mass Effect 2 also features regenerating health as its primary health mechanic, instead of being able to heal with "medi-gel" as in the first game, "medi-gel" is still however used in the game via the power wheel.^[8] In addition, the overheat system for weapons has been replaced with heat sinks that function as ammo clips.^[9] This system is functionally identical to the ammunition systems in other third-person shooters, but instead of having different ammunition types for different weapons, the heat sinks are universal across most standard weapons.^[10]

The characters in Mass Effect 2 are more detailed not only graphically, but technically. In the original Mass Effect, Commander Shepard only had 20 animations for cover, while in Mass Effect 2, the character has over 200. The world is also more open-ended in this installment; uncharted worlds the player could only explore for "cheap thrills" are now more detailed and have more to explore.^[11]

The camera positioning for conversations with A.I. characters has also been improved, the previously static camera now moving around to provide "a much needed cinematic touch."^[12] Another new feature during conversations are context-sensitive controls: in addition to Renegade and Paragon dialogue options, Shepard is able to interrupt the dialogue with cinematics when prompted with the on-screen controls, again along Paragon or Renegade paths.^[13]

The M35 Mako is not included for planetary exploration in Mass Effect 2 due to criticism of the Mako's poor gameplay sections in the first game.^[14] Instead, a Kodiak drop shuttle, which the player cannot directly pilot, deposits the player on foot into areas of immediate interest.^[15]

Unlike Mass Effect, in which there were four weapon types, there are now nineteen different weapons^[16] and the pistol has been broken up into the heavy pistol and the machine pistol.^[17] The grenades from the first game do not make a reappearance, but have been replaced by the new heavy weapons.^[18] Sub-machine guns are shown to be another new weapon class added to the game. Characters are now able to use any weapon their class is trained for at full effect, meaning the player is no longer required to or able to invest in weapon skills. Armor skills have also been removed, and there are no longer class restrictions on armor.^[19] Instead, armor is controlled through purchases of upgrades or individual components, and armor is applied piecemeal, with different armor components providing different bonuses to damage, health, and other skills.

Casey Hudson, project director for BioWare, and Greg Zeschuk, BioWare co-founder, as well as various developers on the official Mass Effect message boards, stated that players should keep their Mass Effect save-files,^[20][21] because decisions made by the player in the first game have influences on their character in the sequel.^[22] Each completed game is viewable by the player when deciding which save to import into Mass Effect 2, and a summary of some of the key decisions made during that game is shown to help the player make sure they import the save they mean to.^[23]

Players who have not played the first Mass Effect start a new character in Mass Effect 2, and are brought up to speed on the story elements that have taken place thus far in the series. Hudson also stated that characters from the previous game make a return, provided that they were not killed.^[20]

When transferring a file from the first Mass Effect, players have the option to change their class to a different one. For example, if the player wanted to play as an Engineer instead of an Infiltrator, the player may change their character's class while still importing the choices made in the first game.^[19] In addition, there is a story explanation as to how the character's abilities have changed.

Players receive bonuses for importing save games; for example, importing a level 60 Shepard provides the player with one hundred thousand credits, ten thousand of each resource, bonus paragon and renegade points, and allows them to start at Level 5. Additionally, the achievement Long Service Medal requires the player to beat the game twice; however, the player can also get the achievement for completing it once with an imported Shepard.^[24]

The first teaser trailer for the game gave the impression that Commander Shepard had been killed in action,^[25] but it was later confirmed that Shepard was brought back to life by Cerberus, providing the player with a chance to change their appearance and character class.^[26] Players themselves dictate whether or not Shepard will die at the end of the game based on choices that they make throughout the game. While exploration in the first game had little relevance to the main story, in Mass Effect 2, the player is able to gather resources for ship upgrades and enemy intelligence that will have an effect on the final mission.^[12] BioWare Executive Producer Casey Hudson explained that "If you do die in the ending of Mass Effect 2, it will not come as a surprise, nor will it be random. It will be pretty obvious that you headed into the final mission knowing that Shepard probably wouldn’t make it out alive." Hudson also confirmed that team members would be affected by the player's decisions during the final mission: "You might have an ending where Shepard’s entire team survives, or where the entire mission is a bloodbath and everyone (including Shepard) is killed, or anything in between."^[27] The ending in which Shepard is killed represents a permanent death for the character in terms of the story, rather than a death where the player simply reloads from the last saved game after making a mistake in combat, meaning Shepard will not be available for Mass Effect 3 in that scenario.^[28]

Mass Effect 2 begins in 2183, not long after the events of Mass Effect. While on patrol for geth, a race of automatons, the protagonist Commander Shepard's ship, the Normandy, comes under attack by an unknown assailant. The ship suffers extensive damage, forcing the crew to evacuate in escape pods. Joker continues to pilot the ship, despite it suffering extensive damage and the rest of the crew evacuating. Shepard reaches Joker, and orders him to get off the ship. Joker insists he can save the ship even though that obviously isn't the case. Shepard drags Joker out of his seat and into a pod, but before he can board himself, the Normandy is attacked again, sending him flying and debris slicing through his suit. He suffocates and clinically dies. His body is seen drifting through space. Commander Shepard's body is retrieved by the Shadow Broker, a secretive buyer of information, selling it to the highest bidder, who has been employed by The Collectors, an enigmatic and xenophobic alien race who serve as the game's primary antagonists. In the events of Mass Effect: Redemption, former squadmate Liara T'Soni is employed by Cerberus, a pro-human group, to get the body for the organization, before it is delivered to the Collectors. After this, Cerberus works to revive the Commander through a project known as "Lazarus." Two years later in 2185, Shepard is awakened aboard a Cerberus space station that is under attack from hacked security mechs, aids Cerberus agents Miranda Lawson and Jacob Taylor in escaping. Shepard is taken to Cerberus' headquarters and granted an audience with the Illusive Man, who explains that Shepard was "upgraded" and asks for the Commander's help in combating a new threat which has been abducting entire human colonies. Shepard and his team are dispatched to the recently attacked colony of Freedom's Progress in the Terminus Systems to investigate. There, the group encounters Tali, one of Shepard's former squad members, and discovers that the mysterious insect-like Collectors were behind the attack. Shepard reports this to the Illusive Man, who then reveals what Shepard's previous squad members are up to. After receiving command of the Normandy SR-2, Shepard decides to begin recruiting a new team to discover the Collectors' plan. Shepard then proceeds through various missions to collect his squad including:

The hero of the first game. Having been resurrected by the pro-human organization Cerberus, Shepard is on a mission to hunt down the Collectors, who are suspected to be working for the Reapers.

A model of the Krogan species created in a lab by a Krogan warlord. He has been programmed with the memories and skills by his creator. Due to the nature of his in-vitro birth, and genetic engineering, he is the most perfect specimen of the Krogan race. However, he has no clan, and little knowledge of Krogan customs.

A Salarian scientist who is also a competent soldier. Like many salarians, he is hyperactive and has many "mad scientist" behavioral traits. He is responsible for creating upgrades for Shepard's team and the Normandy.

An Asari Justicar highly skilled in biotics. She fight for absolute justice, and is tracking down her elusive daughter who has been killing innocents for ages by draining their lifeforce during sexual encounters.

An Asari ardat-yakshi, which like her mother, Samara, is a highly skilled biotics. Morinth also looks almost precisely like her mother, and is able to imitate her in every way.

A member of Cerberus with biotic ability. A former Alliance soldier, he joined Cerberus after viewing the bueracracy of the Alliance as hampering the ability of humanity to survive. He is often put down by Miranda, who he had a brief romantic relationship with.

Genetically modified to perfection by her father, Miranda is the top Cerberus agent on board the Normandy. Driven and devoted to the Cerberus cause, she is often viewed as cold and callous by other Cerberus agents. Other than military and tactical support, she acts as the liaison for the Illusive Man. Miranda has a genetic twin sister that she has spent much of her life hiding from her father, who wished to use Miranda, and now Oriana, to establish a mercantile "dynasty."

A Drell assassin who is dying of an unknown disease. He joins the team in an attempt to repent for his actions in life. He is an expert assassin, but is also gifted in biotics.

A product of a Cerberus experiment to enhance human biotic ability. Jack's hostile persona is the result of torture and captivity she endured while she was

A Geth who is part of the majority of Geth who feel that organic life does have the right to exist. It, like all Geth, is still connected to the Geth collective. It refers to the Geth who seek to destroy organic life as the Heretics. It has a certain fascination with Shepard and saves him on board a reaper ship.

Returns to the Normandy after a scientific study goes horribly awry and most of her team is taken out by Geth. She is working with her father to discover more about the Geth; periodically shipping him pieces of disabled Geth. These actions put her on trial for treason amongst the Quarian as a result of the Geth reactivating and killing everyone on board her father's research ship. This is the reason for the Vas Normandy designation.

After the Normandy was destroyed he pursued a life of vigilantism. He makes an effect mark on the populous of the Omega space station, which is riddled with criminal syndicates. Shepard meets up with him unintentionally while tracking down a man named Archangel who turned out to be Garrus himself. When Shepard finds him he has been holed up for weeks in his base as local crime syndicates send waves of mercenaries to kill him. During a final onslaught he is injured, leaving him disfigured. ^[29]

Mass Effect 2: Original Videogame Score is composed and produced by Jack Wall, Sam Hulick, David Kates, and Jimmy Hinson. The soundtrack was released on January 19, 2010, published by Electronic Arts, featuring 27 tracks on two discs.^[3]

BioWare plans to support Mass Effect 2 with additional downloadable content for the game following its release. This content will range between individually sold weapons and armor, small side-missions, full-sized quests, and large expansion packs. Similar to Dragon Age: Origins, some downloadable content was made available immediately upon the release of Mass Effect 2, and some for free.^[30][31] The first downloadable content available with the game's release allows the player to download a new recruitable character, a mercenary named Zaeed Messani, and adds new missions and in-game items. Bioware has announced that the first add-on would be released Wednesday due to a delay in putting the content online.^[32] A second piece of DLC is also planned, featuring new missions, weapons and a hovering tank known as the Hammerhead.^[33] Available immediatly upon release is Normandy Crash Site add-on that allows Shepard and his team to investigate the remains of the SSV Normandy SR-1.

The team that worked on Mass Effect also worked on Mass Effect 2.^[35] EA CEO John Riccitiello confirmed during a conference call with investors that Mass Effect 2 would be available on "multiple platforms."^[4][36][37] Riccitiello also revealed that Mass Effect 2 would be released on January 26, 2010.^[36]

On March 2, 2009, BioWare and Electronic Arts announced that they had set up a new team, set to work in Montreal, using the existing EA Montreal facility.^[38] The team's main task was to develop Mass Effect 2. Around half of the team of thirty worked on the original Mass Effect, with the others being mostly new hires.^[39] This new team supplemented the teams already working on Mass Effect 2. BioWare co-founder and CEO Ray Muzyka said the team was "really excited about it, and we think it's going to be a huge opportunity to tap into the talent base in Montreal while supplementing our existing teams in Edmonton and Austin, which are doing some great stuff on all the other projects BioWare's working on."^[39]

Following the example of Dragon Age: Origins, the PC version of Mass Effect 2 does not use SecuRom digital rights management software, but instead opts for a standard disc check.^[40]

Mass Effect 2 spans two discs. Windows users need to install both discs and can play the game with one. While it was previously announced that Xbox 360 users would be required to make a single disc swap during a specific point in the storyline,^[6] Bioware later revealed that there will have to be more than one disc swap.^[41]

Mass Effect 2 contains 90 voice actors playing 546 characters, speaking over 31,000 lines of dialogue.^[42] Mark Meer, the voice actor for the male Commander Shepard, suggested that voice recording for the second game was so extensive that it took double the amount of time recording on the first game did. ^[43]

Actors Martin Sheen, Michael Dorn, Carrie-Anne Moss, Yvonne Strahovski, Tricia Helfer, Shohreh Aghdashloo, Adam Baldwin, Simon Templeman and Michael Hogan voice characters in the game. Keith David and Seth Green continue their roles in the series as David Anderson and Jeff "Joker" Moreau respectively.^[44] Voice actor D.C. Douglas, who voiced Albert Wesker in Resident Evil 5, confirmed he would be voicing Legion, a "naturally-evolved" geth that's obsessed with Commander Shepard for unknown reasons.^[45][46] Actor Martin Sheen voiced the Illusive Man, the mysterious leader of the Cerberus organization.^[47]

BioWare project manager Corey Andruko and BioWare lead technical designer Dusty Everman led a 60-minute lecture on level design for Mass Effect 2 at the 2009 Game Developers Conference. The session gave attendees insight into the new approach BioWare is taking in designing levels for Mass Effect, one that maximizes iteration for quality, while minimizing rework and cost. ^[48]

A promotional trailer was released on February 20, 2009. The trailer pans across a very close up set of armor, with captions listing off Commander Shepard's achievements and known alien allies. At the end of the trailer, Shepard's current status is given as "killed in action". The camera then pans upwards to show the head of a geth with armor bearing the N7 logo (part of the Systems Alliance Military Vocational Code and printed on Shepard's default armor) in front of it.^[25] In a development blog Casey Hudson, BioWare's Executive Producer, commented on the rumors of Shepard's "KIA" status, stating "Better not be. We had a lot of big plans made, so if someone’s gone and killed Shepard then things are going to take an unexpected turn…"^[49]

On December 29, 2009 the cinematic trailer for Mass Effect 2 was released.^[50] Additionally, in the months leading up to the game's launch, BioWare released six Mass Effect class walkthroughs narrated by the lead gameplay designer, Christina Norman.^[51]

On May 29, 2009, BioWare released the first full trailer for the game.^[52] It revealed little that wasn't already known or hinted at by the previous trailer and developer diary. This trailer also confirmed that Shepard is alive for the events of Mass Effect 2, and not dead prior to the game as the previous trailer seemed to indicate. BioWare later confirmed that Shepard would not die in the game's storyline until the choices made by the player decided Shepard's fate.^[27]

Mass Effect 2 includes several bonus items for those who pre-ordered a copy of the game or purchased Dragon Age: Origins. If the game was pre-ordered at GameStop or Play.com, players received the Terminus Armor, which grants increased running speed and shields, and the M-490 Blackstorm Heavy Weapon, a gun that creates a gravitational singularity(miniature black holes). If the game is pre-ordered at other retailers, players received the Inferno Armor, which grants a negotiation bonus, increases running speed, and boosts the effectiveness of combat powers.^[1] For purchasing and registering a new copy of Dragon Age: Origins, players also obtain the Blood Dragon Armor which was also a bonus item in Dragon Age: Origins.^[53] Buyers of the Collector's Edition of Mass Effect 2 receive the Collector Armor, which increases a character's maximum health, health regeneration, and running speed, as well as the Collector Assault Rifle, which quickly depletes enemy shields.^[54]

Mass Effect 2 was also released in a Collector's Edition contained in a tin case. The Collector's Edition included the full version of the game, The Art of Mass Effect 2 48-page hard cover art book, the first issue of the Mass Effect Redemption comic book, and a bonus DVD with exclusive "Making of" videos and behind the scenes of the game. It is also possible to buy the Digital Deluxe Edition from EA's online store which is downloaded via the EA download manager and contains digital versions of the art book, the comic book and the official soundtrack to the game.^[55] Valve's Steam service offers the Digital Deluxe Edition for purchase as well.^[56]

The Cerberus Network card was included in all newly purchased versions of Mass Effect 2, which was confirmed on the BioWare message boards.^{[citation needed]} Those who did not buy the game first-hand must purchase access to the Cerberus Network for $15. The Cerberus Network offers an in-game delivery mechanism for free Mass Effect 2 downloadable content, but paid content will not be purchased via the Cerberus Network. A free pack featuring new side-missions, in-game items and Zaeed, a mercenary who joins the player's party, was available for download on launch-day.

Official Xbox Magazine gave the game a 9.5/10, praising the combat as flexible with gorgeous environments. The magazine also liked the "enveloping universe" and the new characters.^{[citation needed]}

Mass Effect 2 received a 10/10 from both Xbox 360 Magazine UK and gamesTM.^{[citation needed]} PC Gamer UK awarded the game 90%. ^{[citation needed]} NowGamer also awarded it 9.8/10 calling it a "gorgeous experience and a staggering achievement". ^[63]

GamingShogun gave the game high marks and even though they referred to the game's final battle as 'cornball', said that despite this the overall game is incredible and easily one of the best games of the young year.^[64]

IGN gave Mass Effect 2 a 9.6/10, calling it one of the most personal games ever made. The cinematic direction, tight gameplay, compelling characters, storyline, and choices were given considerable praise. However, it was criticized as being overly referential to the first entry in the series, as well as minor occasional problems players may experience such as getting stuck in certain environments and having the sound cut out, although not nearly enough to ruin the experience. IGN UK gave the game a 9.2/10 while IGN AU gave it a 9.3/10. ^[59]

Mass Effect 2 received a 9/10 from GameSpot. They cited its dialogue and voice cast, as well as "fantastic" art design, along with level design and shooting mechanics. However, it stated some problems looking for planets and some bugs which were also a problem in the original Mass Effect.^[57]

Mass Effect 2 currently has a 94 (PC)^[60] and 96 (Xbox 360)^[61] rating on Metacritic showing universal acclaim.

• Official website
• Mass Effect Wiki, an external wiki