Metal Gear Solid 2's source code has been leaked on 4chan

(thegamer.com)

174 points | by rishabhd 4 hours ago

8 comments

  • tombert 3 hours ago
    Maybe with the source code, I'd be able to figure out what the hell happened in the last ~2 hours of the game.
    • boricj 1 hour ago
      My favorite tidbit of the series (but it's in Metal Gear Solid 3): in the torture scene where Volgin interrogates Snake in an attempt to discover who is the spy in his ranks, of all the persons present in the room (and if I got everything right from memory):

      - Volgin is not an agent

      - Snake is an agent (USA spy)

      - The Boss is a double agent (Soviet/USA spy)

      - Eva is a triple agent (USA/Soviet/Chinese spy)

      - Ocelot is a quadruple agent (GRU/KGB/CIA/Philosophers spy)

      And of course, after that Volgin then kills Granin thinking he was the spy, but he wasn't.

    • casualscience 2 hours ago
      Not much, just accurately predicted the next 30 years exactly
      • Lammy 4 minutes ago
        I wonder how they must have felt to have coded a 9/11 scenario of Arsenal Gear crashing into the Twin Towers, and then watched it actually happen a few months later.

        This was cut from the game but is still in the source code leak, just commented out! https://www.youtube.com/watch?v=DNSPx-oRV60

        Also note that the source code was leaked on April 30th :p

      • tombert 23 minutes ago
        Everyone focuses on that part, but what the hell was with the girl that could repel bullets but it turns out that it was magnets but actually maybe she does have powers? And what about the weird thing where you start sword fighting your father/president/clone?

        Yeah I know, sure, fake information on the internet. It's so prescient I guess, but the actual story is incomprehensible.

      • lxgr 1 hour ago
    • networked 1 hour ago
    • 2OEH8eoCRo0 3 hours ago
    • jwitthuhn 3 hours ago
      I need scissors, 61!
      • cosmicgadget 31 minutes ago
        Must have been having a stroke...
    • EA-3167 2 hours ago
      Kojima saw the writing on the wall so speak, and told us what the future held in a series of metaphors and dense monologues.
  • e12e 1 hour ago
    • jdw64 8 minutes ago
      very thanks!
  • HerbManic 32 minutes ago
    Being the Vita/360 versions makes this much more usable. I would be having a little panic attack if I had to go back to working on PS2 only code. I mean you came to like the thing but I'm convinced it was a form of digital Stockholm syndrome.
    • boricj 25 minutes ago
      I've only played the original PlayStation 2 release, but wasn't the PS2 release of Metal Gear Solid 2: Substance the version with the most content? I'd take a leak of that one over the other versions.
  • OptionOfT 1 hour ago
    Now do Red Alert 2 and Yuri's Revenge!
  • NotPractical 1 hour ago
    Minecraft Legacy Console Edition apparently leaked on 4chan recently, too: https://github.com/MCLCE/MinecraftConsoles

    Almost no coverage on HN or mainstream media though. Surprising, considering the popularity of this game.

  • charcircuit 3 hours ago
    >this remains a tremendous milestone for games preservation

    Clearly if it was able to be leaked it already was being preserved. It is shameful that such a publication tries and celebrate copyright infringement like this.

    • applfanboysbgon 1 hour ago
      In any sane world not completely captured by corporate interests, the game would already be in the public domain after 25 years. The harm is non-existent.
      • cosmicgadget 29 minutes ago
        Until someone rebuilds it with a Thomas the Tank Engine mod.
    • gwern 3 hours ago
      > Clearly if it was able to be leaked it already was being preserved

      Preserved by whom? Many leaks are done by old or ex-employees who quietly kept a shall we say 'backup' of their work. More than one 'official' re-release has been rumored to be an embarrassed company quietly filing the serial numbers off a rogue leak because they realized way too late that their archival practices were inadequate.

      • 0cf8612b2e1e 2 hours ago
        Anti-emulation Nintendo was caught repacking a pirated ROM.

        https://www.eurogamer.net/did-nintendo-download-a-mario-rom-...

        • Lammy 1 hour ago
          Also how WarioWare: Smooth Moves shows their in-house developers using third-party emulators to source graphics for their first-party nostalgia bait: https://tcrf.net/WarioWare:_Smooth_Moves#Punch-Out (not said derisively; I love WarioWare!)
        • unleaded 47 minutes ago
          What this article is about is that Nintendo used a format standard in the emulation community for the ROM, it's possible they downloaded it but it's not like there's some "downloaded from ROMZ-ZONE.RU" watermark in there. It has been revealed in leaks that Nintendo has an internal ROM vault of pretty much everything ever released on their systems.
        • charcircuit 7 minutes ago
          They were only "caught" using the .NES header which is a public standard that many NES emulators implement. There is no evidence that they used a pirated ROM.
        • Andrex 1 hour ago
          If someone breaks into a warehouse and makes off with a pallet of cartridges, and then those carts are recovered, would it be strange if Nintendo resold those carts? It's their property at the end of the day.

          Aside from that thought exercise, like many "internet facts" this one also might not be true, and repeating it doesn't really help either "side."

          https://medium.com/@AberrantWolf/mario-illegal-roms-and-medi...

    • tfigueroa 3 hours ago
      It’s, what, 25 years old? There have been many sequels, prequels, remastering. The economic benefits of this IP are largely exhausted; that it is now leaked to the commons isn’t an alarming thing.
      • charcircuit 3 hours ago
        The game just had an update to support the Switch 2 only 2 months ago. It is still being used commercially.
        • bigyabai 2 hours ago
          Konami willing, they'll drag the IP to their grave. Lest we forget MGS3's first remaster... for Pachinko parlors: https://www.youtube.com/watch?v=VsJ4QgBpQN8

          Recompilation efforts raise the bar for future re-releases, and incentivize proper remaster efforts like MGS Delta instead of the half-assed Master collection. I would love to see Konami thrive as a company and get more people interested in MGS, but their recent re-releases don't deserve to be priced at $60. Their monopoly of the source code feels like an existential threat to both future preservation and high-quality MGS remakes, it's healthier for Konami to simply let it go at this point.

    • Lammy 1 hour ago
      Crowdsourcing the preservation means the one UND ONLY ONE copy can't be destroyed by fire, flood, disk failure, ransomware, whatever else.
      • charcircuit 1 minute ago
        There is not only one copy. There are many copies under Konami's control. It is also fully up to Konami if they want it to eventually become public or if they just want to delete it and have it never revealed. That is the decision that they themselves have the power to make and leaks like this is stripping them of their creative rights over distribution.
    • wiseowise 1 hour ago
      > It is shameful that such a publication tries and celebrate copyright infringement like this.

      Oh no.

      Anyway.

    • unleaded 3 hours ago
      copyright infringement is awesome
    • themafia 1 hour ago
      Copyrights were only intended to be secure for a _limited_ time. Originally 20 years. Konami has been granted at least 2 decades of FBI backed security of their property. I'd say they got a plenty good deal and have nothing to complain about here.
      • charcircuit 4 minutes ago
        This is a Japanese game and Japan originally had 30 years of copyright. You also can't ignore that the amount of time was extended before the game came out.
    • pdntspa 3 hours ago
      because intellectual property laws are inherently worthy of respect and they are never used against consumers ever
      • charcircuit 1 minute ago
        No consumer is entitled to play a game. They are free to go find another game to play and there are millions of other games out there that they could legally access and play.
  • AnotherGoodName 4 hours ago
    I wonder if it’s a real leak or just an agent recreation of the source from machine code.

    I’ve been having fun lately with agents and decompilation. You can literally point them at any game and ask them to decompile the game and structure and format as if it was the original source code. Asking them to ensure it compiles works fine.

    Some proof: i made online save game editors for jagged alliance 3; grandcheaten.com and news tower; thedailycheat.com (.com domains are only $10 so i figured why not).

    You can do this with any game i’ve found. Older games work best due to the forced simplicity of the source code though.

    • jamesu 3 hours ago
      There is no way you could recreate a convincing enough 90s era codebase of a japanese videogame + its associated tools + scripts and commented out codepaths with current ai tools.
      • sigmoid10 2 hours ago
        I wouldn't be too sure about that. The original decompilations of Mario 64 and Ocarina of Time were done mostly by hand because LLMs weren't really around yet, but these kinds of projects seem perfectly suited for handing the gritty work off to AI: There is a clear output (exact binary recreation) and a straightforward path to get there (look at this assembly code and produce some C code from it). The decompilation of Twilight Princess jumped from very little to basically 100% of core code in the past year alone: https://github.com/zeldaret/tp

        I have no doubt that this would be possible for MGS2 as well.

        • SpecialistK 2 hours ago
          Keep your eyes open for Sonic R too. Sadly a lot of the online Sonic community has been toxic to the dev for being transparent about using Claude for the majority of the disassembly. Even though he's a very talented developer with lots of credit to his name, and only took a few weeks compared to a year+ if fully manual.
          • InvisibleUp 1 hour ago
            Having followed his bsky during his announcement, he started off per-emptively dissing on his haters that... didn't even exist yet. Constantly posting memes about how everyone was dissing him and how AI was totally superior (and then posting his angry sessions with Claude when it got something wrong) when most other users were just "that's cool man". The thing that made him quit bsky was a (now-deleted) thread someone posted criticizing the weird crash-outs. I think he was more... normal about the whole thing, people would have received the project quite a bit more positively.
          • Grazester 2 hours ago
            [dead]
        • paavohtl 1 hour ago
          I don't think it's impossible, but it would take a lot of time and a lot of money; likely more time than good enough models have been commercially available.

          I have been working on an incremental decompilation-based reimplementation (basically how OpenRCT2 was done) of Worms Armageddon for the past 2 months with a lot of help from LLM tools; primarily Claude Code and Ghidra MCP. I've worked on it almost every day, reaching Claude Code Max 5x's 5 hour session limit multiple times every day. Suffice to say as a software rendered, sprite-based 90s PC game, Worms Armageddon is several orders of magnitude simpler than MGS2. Despite that, I think it will be 2-3 more months of work before I can compile a fully independent version of the game.

          This is despite the game being an almost ideal candidate for automated RE, as it uses deterministic game logic with built-in checksum checks in replays and multiplayer. I've downloaded all the speedruns I could find for the game (as replay files) and I've retrofitted the replay system into a massively parallel test framework, which simulates over 600 games in about 30 seconds. So Claude can port all game logic independently without much need for manual testing; the replay tests can almost guarantee perfect correctness.

          MGS2 doesn't have anything like that, so every ported function requires extensive manual testing. Even with LLM tools, an accurate decomp could take years (unless you're willing spend thousands of $currency per month on it).

          • networked 1 hour ago
            This is really cool! Your process is compelling, and your choice of game is excellent. I'd like to read a long blog post about your entire journey from the beginning to a working binary once you get there.

            For those wondering, there is a public Git repository at https://github.com/paavohuhtala/OpenWA.

            • paavohtl 58 minutes ago
              As it happens I do have the habit of writing very long blog posts - though none on OpenWA so far. The OpenWA readme file serves as a bit of an introduction, though it's already a month old.
        • AshamedCaptain 1 hour ago
          Decompilation to C (and even C++!) has been done automatically for 2-3 decades at least. I am not sure what has changed in recent years other than people playing fast and loose with copyright (and GitHub allowing it, likely because their LLMs also stand to benefit). Introducing LLMs here is only going to introduce errors, delays and likely push you away from a reliable result.

          The challenge here is readability. Reading the TP source leak you link I think it's even behind the current state of the art, as it's barely above assembly. This is where I suspect even the smallest of LLMs may help, since you don't care that much if it introduces errors.

          • sigmoid10 23 minutes ago
            >Decompilation to C (and even C++!) has been done automatically for 2-3 decades at least.

            Only in a very rudimentary sense and definitely not in a working compilation (much less binary equivalent) sense. LLMs have turned this from a gimmick for static analysis into something that actually works pretty well for recompilation projects.

        • jamesu 2 hours ago
          My take was more along the lines of: it wouldn't be convincing enough, if anything it would be too clean and perfect.
        • Andrex 1 hour ago
          Does the TP decomp use AI to achieve their speed?
      • CamperBob2 2 hours ago
        That's pre-2026 thinking. At this point, with the ability to lash IDA or similar tools to an agentic harness, there is no longer any such thing as a closed-source binary.
        • wuschel 2 hours ago
          What is the state of the art of compilers here? What size of project are we speaking here?

          What is the experience faulty decompilation, and the existence of bugs in the binary?

          Could one decompile a binary to a more modern language than C?

      • diath 2 hours ago
        Absolutely. This is just some delusions of a vibe coder at best. Not with just current generation of AI tools but essentially never. The conversion from C, C++, Rust or whatever, through post-processing (macros etc), through IR generation, through compile time optimizations, through link time optimizations, to the generated machine code is a one way street for low level languages. You can get a pretty close higher level approximation that matches the flow/logic/structure - but the code will never be anywhere near close to the original source code. I could write the same C++ program in 3 different ways and get identical assembly, how do you go back to the exact source? The answer is that you don't.

        Here's the same simple program, written in 3 different ways, producing identical binary compatible code: https://godbolt.org/z/qWrc8fEnn

        How does the AI know whether it should produce back the snippet #1, #2 or #3? It does not. It cannot.

        • CamperBob2 1 hour ago
          Who cares? Who said anything about recreating the exact code? You will get usable, compilable, and surprisingly readable source code, in your language of choice, that yields the functional equivalent of the binary.

          Barring obvious edge cases that could show up but don't usually, like intentional race conditions. Timing is the one area where things get iffy.

          • wuschel 12 minutes ago
            That is quite incredible if that is true. Need to read a bit into that. Can you point towards relevant literature/examples? Also: please see my questions in the comment to your other reply
          • diath 1 hour ago
            > Who said anything about recreating the exact code?

            The person I'm replying to? Who said you will get the same code as if it were the original source?

    • whywhywhywhy 3 hours ago
      It’s the real code there is code for known removed content (tanker escape scene and the 9/11 removed cutscene). Also AI can’t do what you’re theorizing yet.

      >and ask them to decompile the game and structure and format as if it was the original source code. Asking them to ensure it compiles works fine

      lot of people claiming this the end result is the AI downloading an emulator and rom

      • AnotherGoodName 3 hours ago
        >Also AI can’t do what you’re theorizing yet.

        Did you try the above links? I haven’t shared the full source but all game mechanics listed in the ja3 guide including code snippets where helpful.

      • echelon 3 hours ago
        > It’s the real code there is code for known removed content (tanker escape scene and the 9/11 removed cutscene). Also AI can’t do what you’re theorizing yet.

        There are lots of decompilation community efforts for N64 games, etc.

        Someone should train a model on this. Giving the decompiled symbols good names, etc.

        De-minification and de-obfuscation while we're at it.

        It should be easy to generate a ton of "synthetic" (actually real) training data for this by simply compiling sources and using that as (input, output) pairs.

    • defen 3 hours ago
      Whoa, since when is there a Jagged Alliance 3? Is it any good? JA2 is one of my favorite games of all time
      • AnotherGoodName 2 hours ago
        It’s playable but nowhere near as good and a lot of criticism is warranted. A true ‘70%’ game.

        Gunplay is weak. Accuracy drops off waaaay too fast based on maximum range of the gun and burst fire has arbitrary damage reduction per bullet. So short range guns almost always missed (mechanics documented from source in the above guide) and if they hit they did little damage. It means the only viable weapons are long range weapons. Rifles and assault rifles. A submachine gun is worse than a sniper rifle even at close range.

        The plot has a key gameplay changing moment that triggers waaay to early meaning you have to work to see much of the game content. Everyone tries to avoid the trigger on the second playthrough which is a silly thing to do game design wise. A desire to teleport across the map was the original motivation to the above from my point of view.

        Enemies are bullet sponges in the late game too. A lame way o balance weak ai and gunplay.

        It could have been as good as ja2 but they just didn’t refine the above enough.

    • SSLy 1 hour ago
      check for console headers. those aren't that easy to get out of LLMs
    • bigyabai 4 hours ago
      It's (probably) a real leak. There are original comments in Japanese describing cut content and game logic that was scrapped in the final release.
      • jayd16 3 hours ago
        Raw assets are probably the better tell
    • tuna74 3 hours ago
      How do you verify that everything is correct?
      • AnotherGoodName 3 hours ago
        I’m sure the builds from doing what i’ve been doing won’t generate identical bytecode but it’s fun for the sake of messing with the game or understanding it (eg. The checksum logic for newstowers save game logic was cooy pastable as was the whole save game structure formatting itself and clearly matches the game - it works!). Likewise with all the JA3 mechanics documented in that linked guide.