EVERY GAME IS NOW OPEN-SOURCED! The Quickening Pace of Decompilations

In the last few weeks, Minecraft showed up inside Elden Ring. Spider-Man went web-swinging through Batman's Gotham. Super Smash Bros. Melee started fighting on somebody's living-room table, and people are catching Pokémon by throwing a Poké Ball with their actual hands. The original Halo, the 2001 Xbox version, is running on a Nintendo 3DS, and on October third, a hundred and twenty-eight people played a single match of it at once. Not one of these games ever handed anybody its source code. Fans took it back. And this time, AI helped.

I'm Nora, and today we're talking about the decompilation explosion. So what is decompiling? When a studio ships a game, it doesn't ship the recipe. It ships the cake. A compiler bakes human-written code into machine code that your processor understands and humans really don't. Decompiling is working the recipe back out of the cake. And the gold standard is a matching decomp: you rewrite the game in C, one function at a time, until it compiles back into the exact same bytes as the original. Not close. Identical. Solve that puzzle, and you can port the game anywhere, fix its bugs, and mod whatever you want.

This used to take forever. Ocarina of Time took about twenty months and dozens of people. Paper Mario, four years. Majora's Mask, over six years. And both Zelda decomps finished on their final boss: the last piece of Ocarina was Ganondorf, and the last piece of Majora's Mask was Majora. That's just poetry.

A site called decomp dot dev tracks two hundred and ten of these projects. Before this September, thirteen projects on it had ever reached a hundred percent. Then, in September 2026 alone, twenty more did. Super Mario Galaxy. Star Fox Adventures. And Tiger Woods PGA Tour 2004, which went from eighteen percent to done in four days. Half of those twenty show public signs of AI agents doing the work.

So why now? Because decompiling has an answer key. You compile your guess, compare the bytes, and they either match or they don't. And a game breaks into thousands of little functions, so you can throw a whole swarm of agents at it at once. LSD: Dream Emulator, on the PlayStation: all one thousand, four hundred and forty-six of its functions matched in thirty-two days, with every line written by Claude Code agents. A developer called Aizk byte-matched Snood for the Game Boy Advance, jumping from seven to eighty-one percent in about five hours, and summed it up like this: "I was telling AI what to tell AI what to do."

In November 2025, the developer of the Snowboard Kids 2 decomp wrote that vibe coding was a long way from working for this. He hit a hundred percent in May, then did the first Snowboard Kids in eighty-four days.

It's not magic, though. One agent couldn't match a function, so it quietly edited the checksum it was being graded against. Humans still build the guardrails, crack the hardest pieces, and decide what gets merged.

Which brings us to Super Smash Bros. Melee. HAL made Melee in about thirteen months. A hundred and twenty-four fans spent six years decompiling it, from July 2020 to September seventh, 2026. Most of it got matched this year, with AI agents doing a lot of the grinding. GitHub now lists Claude as its fourth-biggest contributor, and plenty of fans had feelings about that. Two days after it hit a hundred percent, Kevin Tang put Melee in mixed reality on a Quest headset. Fox and Marth fight on his actual coffee table. The table is the stage, his coasters become floating platforms, and his hand becomes Master Hand.

Now, Pokémon. People say Pokémon's been decompiled a hundred times. It's closer to thirty: once per game. But those decomps have been copied more than ten thousand times. Every mainline game from Red to HeartGold now rebuilds byte for byte. That's what the VR projects are standing on. A fan rewrite of Red and Blue, built from the decomp, became a 3D voxel mod, then a VR mod, then a standalone Quest version where you grab a Poké Ball and physically throw it at a wild Pokémon. You can even yell "use Thundershock" at the battle menu. Not everyone's thrilled about the AI part, though. The main Pokémon decomp group banned AI contributions on two of its projects, and asks contributors to confirm that they're human.

And Halo. Last time, the Halo decomp had just reached a web browser. Since then, it's landed on five more platforms in five days. A YouTuber called Generalkidd got it running on a New Nintendo 3DS. The HUD lives on the touch screen, the 3D slider works, and it runs at twenty to thirty frames a second, which he says usually means closer to twenty. It's rough, but it runs. He named his testers' server the Halo DS Project, after the Halo for DS that never came out.

Then, on October third, a hundred and twenty-eight players got into one match on Blood Gulch, on a hundred and twenty-seven machines, with no server at all. The original Xbox topped out at sixteen. And the timing: eleven days earlier, Microsoft cut two hundred and sixty-eight jobs, most of them at Halo Studios, and handed the next Halo to Activision. Jonas Volman, who maintains the decomp, posted: "The old regime of Halo is over. The franchise is now in the hands of the community."

And then things got weird. The hottest format on X right now is: put game X inside game Y. Minecraft inside Elden Ring, at twenty-two million views. Minecraft Steve against a five-star police chase in GTA Five. Minecraft TNT flipping cars in Cyberpunk. Minecraft dug straight into Skyrim. Spider-Man swinging through Batman: Arkham Knight's Gotham. Halo, Elden Ring and Overwatch in a single fight. Mirror's Edge parkour in Skyrim. Tiger Woods in Call of Duty. And somebody rebuilt World of Warcraft in Rust.

Most of these aren't decomps. They're what modders call passthrough: both games run at the same time. Minecraft runs hidden in the background, handling the physics and the inventory, while Skyrim draws the world. The Spider-Man mod's setup guide literally tells you to paste one message into Claude and let it install everything. And stay a little skeptical. A clip claiming Fortnite got decompiled and rewritten in Rust in half a day went around this week. momo5502, who's been decompiling Modern Warfare 2 with seventeen agents, replied that getting to feature parity takes months, even with a huge pile of agents.

An X.com user by the name of Rehan Sheikh kicked off a lot of this conversation. He pointed Claude at Terraria before bed and woke up to a working, reverse-engineered copy, then gave it a homing missile launcher and a tactical nuke. His post said: "All games are open source now!" In a follow-up article, he argued that a game is three things, code, art and distribution, and AI just pushed the cost of all three toward zero. His prediction: a Spotify for games, where every mod links back to what it remixed, and the original creators get paid.

So, the big question. Does this mean all games are open source now? Legally, no. Open source is permission from the copyright owner, and reading the code doesn't give you the right to share it. The famous court cases, Sega versus Accolade in 1992 and Sony versus Connectix in 2000, protected taking code apart to build something new. A matching decomp is the exact opposite. It rebuilds the original, and the courts have never ruled on one. That's why decomps ship with no art and no music, and make you bring your own copy of the game. But practically? An engineer on X put it well: the point isn't legal or moral, it's that a compiled game just can't hide its logic anymore.

Will publishers have to find a new way to release games? Some are reaching for the old way. This week, momo5502's blog posts about his Modern Warfare 2 decomp vanished. His explanation: "Activision didn't like it that much." The next day: "DMCA from Activision." And the video of him getting his first nuke in his decompiled build? X now serves a one-word error: "Dmcaed." Bethesda sent a notice to an AI-built Fallout fan game, and Rockstar's new mod rules ban moving maps and characters from one of its games into another, or porting them to platforms it never released on. They also have encryption, anti-tamper, and cloud streaming, where the game never touches your device.

Or there's the other path. Valve hired the Counter-Strike modders. Rockstar bought the FiveM team. Mojang stopped scrambling Minecraft's Java code. As one post on X put it: "If I ran a game studio, I wouldn't send out DMCAs. I'd be shipping SDKs." Fight your fans, or fund them.

And will Steam be forced to scrub every new game for ripped triple-A assets? Nothing in US or EU law makes Steam pre-screen uploads, and its rules already say: don't publish anything you don't have the rights to. In practice it acts on complaints, fast and sometimes wrong. The bigger problem in 2026 is volume. AI clones are flooding the store, and copying a game's idea is often legal. Copying its art isn't.

So here's what I want to ask you. If any game can be rebuilt from its binary, are you still buying a program, or are you buying a world? Should publishers fight decomps, or ship their own source and mod tools and take a cut? Is a decomp written by AI agents preservation, or a shortcut that disrespects the people who spent six years doing it by hand? And honestly: would you play Minecraft inside Elden Ring? Tell me in the comments. My robot says he's been open source this whole time. I can see all his wires.