Show HN: Decomp Academy – Learn to decompile GameCube games into matching C

Post by teaearlgraycold » Sun, Jun 28, 2026, 4:29 AM UTC

jackpriceburns wrote: post #21

sciencejerk wrote: post #19

I recently heard that Super Mario 64 (N64) modding community reverse engineered the game enough to recreate more-or-less accurate C code that can be compiled in binaries to execute on many popular target architectures. Have you managed to get beloved games into modifiable C code? Or is it more common to invest a lot of work to document assembly language functions? I know some old assembly but no idea what is involved…

Most games will have been written in a higher level language first (like C or C++) and then compiled into assembly. With matching decomp, we write C, compile it to assembly, and see how much it matches the retail assembly. Using this we can write C that we theorise is almost identical to how it would have been written originally. There are things lost during the compilation process (like comments, function names, etc…

Post by asiekierka » Sun, Jun 28, 2026, 4:49 AM UTC

jonhohle wrote: post #17

jackpriceburns wrote: post #8

Earlier quoted context omitted.

AI is being used in many retro game decomp projects! One of the reasons I went down the path of learning decomp myself was because AI had hit a wall. Matching decomp is quite a bit harder than just normal decomp as even simple things like using an if/else instead of a terney actually change the assembly. AI did an amazing job of getting to 95% matches on nearly all functions, but once it got to that tail end, it star…

I say this every time it comes up, but polluting a decomp project with AI generated code is risky, imho. What makes decomp legal (in the US) is that it’s a creative transformation performed by a human and the resulting copyright of the code that just happens to compile to the same binary is owned by the person doing the decompiling. USPTO and court precedent is leaning heavily toward LLM output not being transformati…

Post by charcircuit » Sun, Jun 28, 2026, 4:53 AM UTC

bottlepalm wrote: post #25

I like decomp, but it makes me nervous. Like how safe is it to decompile a game and publish it to like github with all the symbols, addresses, etc..

Post by charcircuit » Sun, Jun 28, 2026, 4:55 AM UTC

OsrsNeedsf2P wrote: post #13

Dumb question about reverse engineering binaries: is there a way to only do it piecemeal? I'm eventually waiting for LLMs and harnesses to get good enough to reverse engineer BFME (old Lord of the Rings game that still has an active modding community), but it's a multi GB sized game that would have to be done in bite-sized pieces. Basically; can you reverse engineer in bite sized pieces, and recompile/customize their…

Post by jonhohle » Sun, Jun 28, 2026, 5:20 AM UTC

asiekierka wrote: post #24

jonhohle wrote: post #17

Earlier quoted context omitted.

I say this every time it comes up, but polluting a decomp project with AI generated code is risky, imho. What makes decomp legal (in the US) is that it’s a creative transformation performed by a human and the resulting copyright of the code that just happens to compile to the same binary is owned by the person doing the decompiling. USPTO and court precedent is leaning heavily toward LLM output not being transformati…

Does it being a creative transformation rob the derivative work status? Personally, I'd liken the process of decompilation to that of translating a book from one language to another - the copyright on the original work does not become void merely because the process of translation requires extensive creativity. Nicalis and Take-Two have both gone after decompilation projects, also. In particular, Nicalis has gone aft…