The biggest leaks in PC gaming history

Gaming leaks: They happen. Sometimes they're the result of hackers and dataminers, other times they're caused by rogue employees or contractors, and occasionally they're the result of a simple accident like someone pushing the wrong button or emailing the wrong person. However they happen, leaks in videogamedom are real and surprisingly frequent.

Videogame leaks have led to screenshots, videos, code, and even playable versions of entire games bolting from the barn ahead of schedule. Fan reaction can cover a broad spectrum: Excitement over a game that looks great, caution due to potential spoilers, or disappointment that a game—even though it's not out yet—doesn't live up to expectations.

And for developers and publishers, leaks aren't just an ongoing problem but a real source of concern, not just from a security standpoint but from the judgement that comes from people seeing their unfinished work. Do you have a first draft of a novel somewhere on your computer? Imagine if you woke up tomorrow and discovered the whole world was reading it and pointing out all its flaws.

Below we've collected some of the biggest and most notable leaks in PC gaming history, from upcoming games like GTA 6 to blockbusters like Mass Effect 3 to older gems like 2003's original Stalker: Shadow of Chernobyl.

Grand Theft Auto 6

In September, Rockstar Games suffered a "network intrusion" that lead to around 90 videos of in-development GTA 6 footage being leaked to the internet. The footage, which was verified as genuine by Rockstar, confirmed a few rumors about the game, like that it will feature the series' first female protagonist and take place in Vice City. 

The footage mostly consisted of short clips in debug mode, though a few longer sequences, like a diner robbery and a chat with a conspiracy theorist, were also revealed. While the overall story, most character details, and major missions were not spoiled, this hack still represents a major breach of one of biggest gaming companies making one of the most highly anticipated games ever, and it's pretty shocking a hacker was able to access so much information and material.

The same hacker may be responsible for a major hack of Uber around the same time. The FBI is already investigating.

Pretty much every Assassin's Creed game ever

Ubisoft has a long, long history of leaks of its games, especially when it comes to the Assassin's Creed series. Most recently, details about multiple upcoming AC games were leaked ahead of 2022's Ubisoft Forward presentation, including Mirage, Infinity, and a game code-named Assassin's Creed Red set in Japan. 

These particular leaks were the result of a YouTuber who'd signed an NDA with Ubisoft but released the details of the games on a secondary twitter account, for... reasons? Anyway, he got busted.

But this certainly wasn't the first time an Assassin's Creed game was revealed before it was intended to. Originally code-named Assassin's Creed: Victory, details about the game that would become Assassin's Creed: Syndicate leaked well in advance of the launch. Assets included gameplay videos and the revelation that the game would take place in Victorian London.

Leaks are nothing new for Ubisoft, whose sprawling operation on several continents and scores of employees (ever watched the credits for a Ubi game?) apparently make it nigh-impossible to keep a lid on their business. Games like Watch Dogs 2, The Division, Far Cry Primal, and other AC games have all had information leaked ahead of schedule.

Crysis 2

A full month before its release date in 2011, a nearly complete build of Crysis 2, including multiplayer mode and online authentication keys, leaked onto a number of torrent sites. While it was buggy and contained a number of placeholder assets, it was still reportedly playable start-to-finish.

Lamentably, Crysis 2 went on to become the most pirated game of the year, and while it's suspected that the leak came from an employee of either Crytek or EA, the culprit has never been publicly identified.

The Witcher 3

The highly anticipated third entry into CD Projekt Red's The Witcher series was preceded by a massive info leak after the Google Drive contents of an employee was made public. Among the leaked files lay secrets about the RPG's story, enemies, quests, notes on "boob physics," and even the game's multiple endings.

The temptation to dive into the details of such an eagerly awaited game must have been enormous for fans, but we hope you managed to enjoy the surprises anyway. This wasn't The Witcher's first brush with leaks: several gameplay videos of The Witcher 2 were also spilled ahead of schedule.

Mass Effect 3

After an early build of Mass Effect 3 somehow leaked onto Xbox Live, dataminers dove into the code and resurfaced with a copy of the unfinished script. Lots of people had a look, a naturally lots of them then immediately began complaining about the contents.

Still, feedback is feedback. BioWare co-founder Ray Muzyka said they take fan feedback seriously, even if their fans are offering notes on a script they weren't supposed to see. Among the changes made to the final script may have been a few rewrites based on the notes they received on their leaked version.

Doom 3

In late 2002, over a year before its actual release, a demo of Doom 3 shown at that year's E3 was leaked onto the internet, allowing those who downloaded it to play the intro sequence and several early levels of the game.

According to a memo supposedly written by John Carmack (which, if real, was also leaked), the source of the leak was an employee at ATI, who was later fired as a result. None of that is confirmed, though, and whether the leak was accidental or deliberate isn't known.

Half-Life 2 and Counter-Strike: Source

Originally planned for September of 2003, we wouldn't see the release of the Half-Life sequel until a full 13 months later after Valve's network was cracked and the source code, maps, models, and playable builds of HL2 and Counter-Strike: Source were stolen and leaked.

The culprits were eventually arrested by German authorities after Gabe Newell pretended he was interested in hiring one of the hackers to work at Valve and obtained his contact information. The trial resulted in a two year probationary sentence for one of the hackers, and Half-Life 2 wasn't officially released until November of 2004.

StarCraft 2: Heart of the Swarm

The expansion for Blizzard's StarCraft 2: Wings of Liberty was released in March of 2013, but part of it arrived ahead of schedule. A video of the ending of the single-player campaign was leaked before the expansion itself landed. While it was a rough animatic without lip-syncing and containing some placeholder storyboards, it was still a massive spoiler for the story.

While Blizzard wouldn't confirm it was genuine, lawyers quickly issued cease and desist letters to sites hosting the video, which is was a pretty strong indication the leak was the real deal.

Call of Duty: Modern Warfare 3

Back in May of 2011, Kotaku received a ton of information on the upcoming Call of Duty: Modern Warfare 3, roughly six months before it was scheduled for release and before it had even been officially announced. This info included details of the story, screenshots, and details about the game's weapons, levels, and modes, apparently from multiple sources within the developer and publisher.

In response, the developers had to accelerate their own marketing plan, and immediately released a number of trailers for the game.

Dishonored 2

We learned of the existence of Dishonored 2 in a rather embarrassing way: while rehearsing its first ever E3 press conference, Bethesda broadcast—live on Twitch, no less—a conversation between members of Arkane Studios (developer of Dishonored) that mentioned Harvey Smith (director of Dishonored).

After a few minutes of chatter someone finally realized it was going live over the internet and shut it down, but it was too late: a couple thousand fans had been listening the whole time.

World of Warcraft: Cataclysm

Before taking part in a closed alpha, participants are often required to agree not to share details of their experiences. What's harder is actually making sure they abide by that agreement, as with World of Warcraft: Cataclysm. Prior to the expansion's appearance at BlizzCon, one alpha tester posted huge amounts information about Cataclysm online, including screenshots and videos, details on character classes and races, dungeons, and other features.

The information was removed after Blizzard issued a takedown, reminding the player that 'NDA' stands for non-disclosure agreement and is, y'know, legally binding.

Stalker: Shadow of Chernobyl 

In 2003, a pre-alpha for Stalker (which wouldn't even come out for another four years) was leaked onto P2P networks, and while it took some configuration to get working and was missing things like enemies and animals, it was still playable.

Ironically, the mod called Lost Alpha, which attempted to restore the game to its pre-release promise, was also leaked ahead of time by beta testers, forcing the modders to release their work early and ruining their plans for it to become an official paid expansion.

This article was originally published in 2015 and has since been updated.