Mass Effect is a military science fiction media series created by Casey Hudson. The series shows a future where humans and many alien civilizations have settled across the galaxy using technology left behind by ancient, advanced civilizations.

The series began with a set of video games made by BioWare and first released by Microsoft Game Studios for the first two games and their expansions. Later, Electronic Arts took over the series after buying BioWare. Each game is a third-person shooter that includes role-playing features. The first three games form a trilogy where the player controls Commander Shepard, a character who tries to protect the Milky Way galaxy from a group of ancient, sleeping machines called the Reapers. The first game, Mass Effect (2007), follows Shepard's investigation into Saren Arterius, one of the Reapers' agents. Mass Effect 2 (2010) takes place two years later and shows Shepard fighting the Collectors, an alien group that captures human colonies to help the Reapers return. The trilogy's final game, Mass Effect 3 (2012), describes a war between the Reapers and the rest of the galaxy. A fourth game, Mass Effect: Andromeda (2017), introduced new settings and characters, and a fifth game is currently being developed.

The original trilogy was both commercially successful and widely praised by critics. Reviewers highlighted the game's story, characters, voice acting, world-building, and the way player choices affect the game. The ending of Mass Effect 3 was criticized for being unsatisfying, leading Electronic Arts to release an expanded version with extra scenes. Mass Effect: Andromeda received mixed reviews. Some praised its graphics and combat, while others pointed out technical problems and issues with its story.

The series has sparked discussions about how it portrays same-sex relationships and other sexual minorities. It also introduced the dialogue wheel, a feature that lets players choose from preset options to guide conversations, similar to dialogue trees. This mechanic has been used in many other role-playing games. The success of the video game series led to adaptations in other forms of media, including books, comics, and an animated movie.

Setting

The Mass Effect original trilogy takes place in the Milky Way near the end of the 22nd century. In 2148, humans found an alien base on Mars and discovered that Charon is actually an alien structure called a "mass relay," which allows faster-than-light travel to other mass relays across the galaxy. These discoveries helped humans improve their technology quickly.

Humans met many other alien species, some much more advanced than humans. The first meeting led to the First Contact War, but the Council, a group that rules the galaxy, helped stop the war and welcomed humans. Important alien species include the asari, a race of beings that look like human women; the salarians, an amphibious species with high intelligence and fast metabolism; and the turians, a militaristic race of bird-like humanoids who fought humans during the First Contact War.

The Council’s main center of power is the Citadel, a massive space station and another alien artifact. Like the mass relays, the Citadel is believed to have been built by the Protheans, a race thought to be the ancestors of all species but now gone. Over the next few decades, humans gained new technology, allowing them to settle new planets. They also joined the Citadel Security (C-Sec) forces, a respected role that other species had long wanted, causing some to feel resentful. Many conflicts between species still existed when the first game began, remnants of past wars.

The first three games follow Commander Shepard, a special forces soldier in the Earth’s Systems Alliance Navy. After an Earth colony finds a new Prothean artifact, it is attacked by an unknown ship. The Council appoints Shepard as the first human SPECTRE, an elite agent with special authority, to investigate.

Shepard interacts with the artifact and sees visions of war and death across the galaxy. Shepard later learns that the attacking ship is one of many artificial lifeforms called Reapers. Every 50,000 years, the Reapers destroy all advanced life in the Milky Way to allow younger species to grow and avoid endless war, a plan left behind by the Protheans. In this cycle, the Reapers’ return is being influenced by Cerberus, a human-focused terrorist group led by the Illusive Man, who believes they can control the Reapers for human benefit. Shepard and allies discover the Citadel is key to stopping the Reapers and deciding the galaxy’s future.

The fourth game takes place in the Heleus Cluster of the Andromeda galaxy, 634 years after the first game. During the events of the first three games, races from the Milky Way sent ships to Andromeda to build the Nexus, a space station and future colonies. After traveling for over 600 years in cryogenic sleep, they arrive to find the Heleus Cluster in conflict between two native groups: the Kett, a violent race that tries to copy other species’ traits through a process called "exaltation"; and the Angara, a passionate humanoid species whose civilization was nearly destroyed by the Kett.

The Heleus Cluster also has ruins from the Jardaan, a race that used powerful technology to make planets livable in the cluster, which was otherwise dangerous. The Jardaan left the cluster three centuries before the Milky Way races arrived after a long battle with an unknown enemy. During the battle, a weapon of mass destruction was used, causing a destructive energy event called the Scourge, which damaged the Jardaan’s terraforming systems. After the Jardaan left, the Angara, genetically engineered by the Jardaan, began to build their own society before being attacked by the Kett.

When the Milky Way races arrived, Pathfinder Ryder (a character customizable by the player) and their allies had to stop the broken terraforming systems, deal with attacks from the Kett and Angara, and make planets safe for future settlers.

Gameplay

The Mass Effect games are action role-playing games. Players choose their main character’s appearance, background, and one of six classes. Each class focuses on combat, technology, or biotic skills, similar to abilities seen in other games. As characters gain experience, players can improve their skills through a system called a skill tree. Each game follows a main story with choices that lead to different paths and side missions. Players often use their ship to travel through space, visit planets, and complete objectives.

When exploring planets, players can take up to two crew members who act on their own but can follow orders. Missions involve searching for items, talking to characters, and finding key objects. Combat happens in third-person view, with players using weapons, powers, and the environment to defeat enemies. There are six weapon types: assault rifles, grenades, sniper rifles, shotguns, pistols, and later, heavy weapons like grenade launchers. Weapons are collapsible, allowing players to carry multiple types. Melee weapons include fists, gun butts, or later, a blade called an Omni-blade.

Players meet characters and choose responses during conversations. These choices appear on a Dialogue Wheel, with options shown around a circle. Some choices affect how the story progresses or influence the player’s character’s morality, labeled as Paragon or Renegade. In later games, choices during dialogues could interrupt action and change outcomes. In Mass Effect: Andromeda, BioWare replaced the Paragon/Renegade system with a new one based on four ideals: emotional, logical, casual, and professional.

Side missions include building relationships with crewmates, including romantic options. Players can improve relationships through dialogue, gifts, or tasks. Romance options include heterosexual, homosexual, and inter-species relationships, depending on the player’s character. These choices led to some debate when the first game was released, as some reporters criticized the game’s content.

Games

Mass Effect (2007), the first game in the series, was originally made for the Xbox 360 but was later made available on Windows by Demiurge Studios in 2008 and on PlayStation 3 by Edge of Reality in 2012. The game follows Commander Shepard, the main character, as they try to stop Saren Arterius, a rogue agent, from leading the Geth, a group of thinking machines, to take over the galaxy. While chasing Saren, Shepard builds important relationships with other characters, especially their team members, and learns about a bigger threat called the Reapers. Saren has been controlled by a Reaper named Sovereign and is trying to destroy all advanced life in the galaxy, a cycle that happens every 50,000 years.

Two extra game content packs, Bring Down The Sky and Pinnacle Station, were released in 2008 and 2009.

Mass Effect 2, the second main game, was released on January 26, 2010, in North America and January 29, 2010, in Europe for Windows and Xbox 360. Before its release, the game was kept secret, and BioWare’s Project Director, Casey Hudson, said that choices made in the first game would affect the story in Mass Effect 2. The game takes place two years after the events of Mass Effect. Human colonies are being attacked, and their people are disappearing. Shepard must work with Cerberus, a pro-Human group, to find the cause. Evidence shows that the Collectors, a mysterious insect-like race, are behind the attacks. The Collectors are helping the Reapers. Shepard leads a dangerous mission to stop them, with a team of soldiers, assassins, and specialists. Mass Effect 2 received high praise for its story, characters, and gameplay. A PlayStation 3 version was released on January 18, 2011.

Seven episodic expansions were added as downloadable content, including Normandy Crash Site, Zaeed – The Price of Revenge, Firewalker, Kasumi – Stolen Memory, Overlord, and Lair of the Shadow Broker in 2010, followed by Arrival in 2011.

Mass Effect 3, the third game in the trilogy, was released on March 6, 2012. Casey Hudson said it would be easier to make because it would not need to connect to a future game, but choices from the first two games still affect the story. In this game, the Reapers return and attack Earth. Shepard must escape Earth and gather allies to stop the Reapers and break a cycle that has happened for millions of years. The first trailer was shown on December 11, 2010, during the Spike TV Video Game Awards. This game was not made with Microsoft Game Studios and was released on the same date for Xbox 360 and PlayStation 3.

Four story-focused expansions were added as downloadable content, including From Ashes, Leviathan, and Omega in 2012, followed by Citadel in 2013. Five free downloadable content packs were also released for the multiplayer part of the game in 2012 and 2013, adding new characters, weapons, maps, and enemies.

Mass Effect: Andromeda, the first game in a new series and the fourth major game overall, was announced at E3 2015 and released on March 21, 2017. It uses the Frostbite 3 engine and was made for PlayStation 4, Windows, and Xbox One. Andromeda is the first game in the series with an open world. Set in the 29th century, players control Sara or Scott Ryder, a Pathfinder who explores the Andromeda Galaxy. Unlike earlier games, Andromeda did not have single-player expansions, but the multiplayer part received updates in 2017 with new content.

In 2020, BioWare said a new Mass Effect game was being developed. A trailer was released on December 11, 2020, showing a sequel to the original trilogy and featuring Liara T’Soni, a character from the first games. The new game will use the Epic Games Unreal Engine, the same one used in the original trilogy, instead of the Frostbite engine used in Andromeda.

In November 2022, BioWare announced that some developers from the original trilogy would return for the new game. Concept art and an encrypted audio file featuring Liara T’Soni were also released.

In November 2023, a short teaser trailer and poster for the new game were shown after an online puzzle game. Project Director Mike Gamble said veteran developers from the original trilogy would return.

Mass Effect Galaxy is a game set between Mass Effect and Mass Effect 2, available only on iOS. It tells a story about Jacob Taylor and Miranda Lawson, characters who appear in Mass Effect 2. Jacob defends a ship attacked by batarian raiders and later helps investigate the batarians’ actions. The game was removed from the iOS App Store.

Mass Effect Infiltrator is a third-person shooter available on Android, BlackBerry 10, iOS, and Windows Phone 8. It follows Randall Ezno, a Cerberus agent who turns against Cerberus and frees prisoners. Players earn rewards for exposing Cerberus’ crimes, which affect the “Galaxy at War” system in Mass Effect 3. The game was removed from all app stores.

Mass Effect: Datapad was a free app for iOS devices that let players check the status of the galaxy map in Mass Effect 3 and receive messages from characters. It included information about the game’s universe and mini-games connected to the “Galaxy at War” system. The app was removed from the iOS App Store and Google Play Store on June 5, 2013.

Other media

Original trilogy tie-in novels published by Del Rey Books:

• Mass Effect: Revelation (2007), written by Drew Karpyshyn: This is the first novel based on Mass Effect. The story focuses on then-Lieutenant David Anderson and explains how he met Saren and began his relationship with Kahlee Sanders. It adds more details about the history of the Mass Effect universe and describes how Anderson failed to become the first human Spectre.
• Mass Effect: Ascension (2008), written by Drew Karpyshyn: This is the second novel based on Mass Effect. The story follows Paul Grayson, a member of Cerberus, who is responsible for training a biotic girl named Gillian. The events take place about two months after the ending of the first game.
• Mass Effect: Retribution (2010), written by Drew Karpyshyn: This is the third novel in the Mass Effect series. It was released on July 27, 2010, and is a sequel to Mass Effect 2 and Mass Effect: Ascension.
• Mass Effect: Deception (2012), written by William C. Dietz: This is the fourth Mass Effect novel, focusing on Gillian Grayson. Many fans criticized the book for not matching the story details and character traits from the games. Because of this, BioWare and Del Rey decided to make changes in future editions of the book.

Mass Effect: Andromeda tie-in novels published by Titan Books:

• Mass Effect: Nexus Uprising (2017), written by Jason M. Hough and K. C. Alexander: This is the first of three books connected to Mass Effect: Andromeda. The story happens at the same time as the events in the game.
• Mass Effect: Initiation (2017), written by N. K. Jemisin and Mac Walters: This is the second book in the Mass Effect: Andromeda trilogy.
• Mass Effect: Annihilation (2018), written by Catherynne M. Valente: This is the third and final book in the Mass Effect: Andromeda trilogy.

Art books published by Dark Horse Comics:

• Art of Mass Effect (2007), published by Prima Games: This book shows design sketches and concept art created for the original Mass Effect game.
• The Art of the Mass Effect Universe (2012), published by Dark Horse Comics: This book includes art, sketches, and paintings from all three Mass Effect games, including pieces from the first art book.
• The Art of Mass Effect: Andromeda (2017), published by Dark Horse Comics: This book features art, sketches, and paintings created for Mass Effect: Andromeda.
• The Art of the Mass Effect Trilogy: Expanded Edition (2021), published by Dark Horse Comics: This is a revised version of The Art of the Mass Effect Universe. It includes all the content from the original book and over 90 new pages of artwork focused on the trilogy’s downloadable content and Mass Effect 3’s multiplayer mode.

Comic books published by Dark Horse Comics:

• Mass Effect: Redemption is a four-part comic series released between January and April 2010. The story focuses on Liara T'Soni and takes place between the prologue and main story of Mass Effect 2. It is connected to the downloadable content "Lair of the Shadow Broker."
• Mass Effect: Incursion is an online comic (8 pages) that follows Aria T'Loak’s encounter with the Collectors one week before the start of Mass Effect 2. The events link to Mass Effect: Redemption. It was released on June 21, 2010, through IGN.
• Mass Effect: Inquisition is an online comic (8 pages) written by Mac Walters. The story takes place after Mass Effect 2 and follows Captain Armando-Owen Bailey as he investigates Executor Venari Pallin and corruption in C-Sec. It was released on October 26, 2010, through USA Today.
• Mass Effect: Evolution is a four-part comic series. The first issue was released in January 2011. The story explains the origins of the Illusive Man and takes place during the First Contact War, shortly after the discovery of the Mass Relays.
• Mass Effect: Conviction is a free, 10-page comic written by Mac Walters. The story takes place before Mass Effect 3 and follows Lieutenant James Vega during his time on Omega before returning to the Systems Alliance. It was released in September 2011 through a digital promotion.
• Mass Effect: Invasion is a comic series (4 issues) released between October 2011 and January 2012. The story follows Aria T'Loak, the pirate queen of Omega, as her station is attacked by a new threat from Cerberus.
• Mass Effect: Homeworlds is a comic series (4 issues) written by Mac Walters and released on April 25, 2012. Each issue focuses on a main character from the Mass Effect series.
• Mass Effect: Blasto: Eternity Is Forever is a 14-page comic written by Mac Walters and released on

Development and history

Mass Effect started as an idea in 2003 by BioWare project director Casey Hudson, who shared it with the company's co-founders, Ray Muzyka and Greg Zeschuk. Hudson wanted BioWare to create its own science fiction story that could match the size and detail of the Star Wars universe. On October 11, 2007, just before the original Mass Effect game was released for the Xbox 360 in November 2007, it was announced that EA purchased VG Holding Corp., a partnership between BioWare and Pandemic Studios formed in November 2005. This purchase included the Mass Effect intellectual property, and BioWare continued to develop the series.

The technology in the Mass Effect series is based on the idea of dark energy, a type of energy thought to help the universe expand and possibly enable faster-than-light (FTL) travel. In the game's fictional world, a material called Element Zero, or "eezo," is used to create "mass effect" fields by applying strong electric currents. A positive current increases the mass of objects, creating artificial gravity, while a negative current decreases mass, making FTL travel more efficient. The stronger the current, the greater the effect. Other real-world scientific ideas explored in the series include 3D printing for the omni-tool, hard light technology, and hypervelocity weapons. Hudson believed that real scientific discoveries often inspire creative ideas, saying that "reality will continue to be stranger than fiction," which supports the series' creative choices.

The morality system in the first three main Mass Effect games uses "Paragon" and "Renegade" points, which build on the light and dark side morality system from BioWare's earlier game, Star Wars: Knights of the Old Republic. A Nintendo DS game called Mass Effect: Corsair, inspired by Star Control and featuring a space pirate character, was briefly planned in 2008. However, the project was canceled due to high costs and low expected sales, and the team shifted focus to Mass Effect 2. For Mass Effect: Andromeda in 2017, the Paragon and Renegade system was removed entirely.

In 2007, BioWare applied for a patent for the Dialogue Wheel, a "graphical interface for interactive dialog." The patent was granted to EA International Studio and Publishing Ltd. in 2011.

The Mass Effect universe draws inspiration from other science fiction works, such as Star Trek, Blade Runner, Firefly, and Battlestar Galactica. Other influences include Alien, Starship Troopers, Dune, and Final Fantasy: The Spirits Within. Video games like Deus Ex, Halo, and Starflight also shaped the series' gameplay.

Greek mythology is reflected in the series through names like the planet Elysium and the group Cerberus, as well as themes in story arcs, such as the Protheans' legacy.

The music in the series is inspired by the electronic score of Blade Runner, creating a mood that matches the wonder and fear of space exploration. Composer Jack Wall used sounds from the 1970s and 1980s, blending them with organic elements for the first game. Later games used more orchestral styles, with composers like Clint Mansell, while keeping some of Wall's earlier work.

Reception

The original Mass Effect trilogy received high praise from critics on all platforms, according to the review website Metacritic. Each game in the trilogy was nominated for awards and won several year-end honors from video game publications and major award events. The first two games in the series are often regarded as some of the best games ever made. Mass Effect 2, in particular, was the most highly praised game in the series and won many "game of the year" awards after its release. It received more than 70 perfect scores from critics. In 2013, IGN ranked the Mass Effect Trilogy as the best Xbox 360 game among 25 titles and the 7th best PlayStation 3 game among 25 titles.

The fourth game, Mass Effect: Andromeda, received mixed reviews from critics. Many said it did not match the quality of earlier games in the series, though some praised its improved combat system.

The Mass Effect series was successful commercially. The first game sold more than one million copies worldwide within three weeks of its release. By January 2008, sales had reached 1.6 million copies after six weeks. Its sequel, Mass Effect 2, sold over two million copies to retailers in its first week. It sold more than 500,000 copies during its release month, even though it launched near the end of the month. Before the third game was released, the series had sold a combined total of 7 million copies worldwide. Mass Effect 3 was the most successful game in the series: it sold over 800,000 copies in its first 24 hours, and its first month of sales was twice that of its predecessor. It sold over 900,000 copies on the Xbox 360 version, which outsold the PlayStation 3 version by a ratio of 4 to 1. The game earned over $200 million in revenue. By April 2012, it had sold more than twice as many copies as Mass Effect 2 during their respective launch months and had sold over six million copies in total. By July 5, 2014, the entire Mass Effect series had sold 14 million copies worldwide.

Mass Effect: Andromeda continued the series' sales success. By May 2017, an analyst reported that at least 2.5 million retail copies of the game had been shipped, generating $110 million in revenue. In March 2017, $53 million in net sales from digital and special editions of the game were recorded, though these sales were reported later.

Legacy and cultural impact

Tauriq Moosa from The Guardian praised the Mass Effect franchise as one of the best science fiction series ever made. He described its main theme—“aspiration and connection in the face of an indifferent cosmos”—as being as thoughtful as Star Trek, as hopeful as Asimov, and as dramatic as Battlestar Galactica. Jessi Sampson from PCGamesN agreed, calling Mass Effect an “impressive mix of ideas” from many important science fiction works. She noted that the ambition of the first game and its creators influenced the video game industry and left a lasting legacy. Jonathan Wood from Wired said the first Mass Effect set a high standard for storytelling in video games, one that few others have matched. Benjamin Bullard from Syfy pointed out that when the first game was released, science fiction video games mostly focused on conflict and violence between aliens and humans. Since then, the Mass Effect franchise has grown from a small role-playing game into a major, widely recognized video game series.

In 2010, GamesRadar called Mass Effect the best new franchise of the (then seventh) generation, praising its galaxy setting as “so well-constructed that it felt like a decades-old franchise.” Colin Moriarty stated that Mass Effect is one of the most important video game franchises of that generation. Kyle Munkittrick from Gizmodo argued that Mass Effect is the most significant science fiction universe of the current generation. Patrick Carlson from PC Gamer said Mass Effect is one of the greatest and most personal science fiction stories across all forms of media, combining the best parts of classic space operas with an RPG adventure format that allows players to face both fun and serious challenges. Cian Maher from TheGamer credited the series’ detailed written entries in the game’s codex with helping create “one of the most fascinating universes in video game history.”

N7 Day is an annual event celebrated on November 7 by BioWare, Electronic Arts, and fans of Mass Effect. It began in 2012 as a marketing effort by BioWare to honor the Mass Effect franchise. The term “N7” refers to Commander Shepard’s in-game military rank: “N” stands for special forces, and “7” represents Shepard’s high rank in the game’s universe.

The Mass Effect franchise has inspired many fan-created works, including:

• Mass Effect: Assignment (2012): A fan film set in the same timeline as the games, following two N7 soldiers, Meer and Hale, who hunt a smuggler named Defoe. The film was made by Sneaky Zebra and allows viewers to choose the story’s path, leading to four different endings. Three teaser trailers were released in December 2011, and the full film was released in February 2012.
• Red Sand (2012): A fan film that serves as a prequel to the series, set 35 years before the games. It tells the story of ancient Prothean ruins on Mars. The film features Mark Meer, the voice actor for the male version of Commander Shepard, as Colonel Jon Grissom. It was created by students and faculty at the University of Advancing Technology in Arizona.
• Mass Effect: Pick Your Path (2012): An interactive fiction novel written by Mike Kayatta that follows a merchant who follows Commander Shepard across the galaxy. The story allows readers to make choices similar to the games, affecting the ending and even romance options. It was published by The Escapist in March 2012.

The Mass Effect series has faced several major controversies. A scene from the first game, which included partial nudity and sexual activity, was criticized by some media outlets as inappropriate in 2007. A version of the scene showing a potential romantic moment between Liara T’Soni and a female Commander Shepard led to government scrutiny and a brief ban of the game in Singapore. This controversy caused BioWare to remove planned same-sex romantic content for characters like Jacob Taylor and Jack in Mass Effect 2.

Although Mass Effect 3 received praise from critics, its ending sparked strong public backlash. Many players were unhappy with the conclusion of the trilogy and organized online campaigns to demand a better ending. Both the U.S. Federal Trade Commission and the British Advertising Standards Authority received complaints about BioWare misleading consumers. BioWare later released an “extended cut” patch to expand the endings but not replace them. The company also faced accusations of unethical business practices related to the Mass Effect 3: From Ashes DLC and potential conflicts of interest involving video game personality Jessica Chobot.

Other controversies include public anger over claims that the series’ violent combat was linked to the Sandy Hook Elementary School shooter, a claim later proven false. A propaganda video using assets from Mass Effect 2 to support Donald Trump’s 2016 presidential campaign was removed after copyright complaints from publisher EA. The series has also faced criticism over how it portrays women and sexual minorities.