FE Fates SE - castle.bin.lz

Hello! I recently dumped my copy of Fire Emblem Fates Special Edition onto my PC, but my cousin helped me compile my files back into a .3ds file, and I would like to access them in order to access the castle.bin.lz file in the game. I have tried to use multiple tools in order to access them but each one of them failed in one way or another. Do you know an effective way to access a .3ds file in order to fix a castle.bin.lz file? I tried to apply the fix using the Citra cheats bar, but that hasn’t worked at all. If for some reason this is the wrong place to ask, I’ll find something on my own. Thank you very much.

The title doesn’t describe the issue. What is castle.bin.lz? What about it are you trying to fix? Doesn’t sound like it’s related to Citra. So confused :confused:.

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I’m almost 100% that there isnt a way to decompile the .3ds file and recompile it yet. You’re going to have to start from step 1 and recompile it with the fixed file.

Actually it turns out that you can use this tool to do what you’re trying to do:


I assume you already know how to uncompress the .lz files by now if you’re looking for a way to get to it.

This is related to Citra… how? @Fawful we don’t even know what OP was trying to do…

Yeah the topic was only adjacently related to citra because what this person was trying to do was get around a complication with his 3ds rom that was only there because he decrypted it for use with citra.

Thank you all. I’m sorry for the confusion. I initially had a file called castle.bin.lz, in which was part of a cheat code to use with BootNTR. I was not really sure how to remove the file extensions to process the data into NCSD, but I did not want to break the community guidelines in case this was somehow related to “Warez” or anything else that would violate the guidelines.

If I’m reading this right, it sounds like castle.bin.lz is one of the files within the game, so to create a playable ROM just from that isn’t possible. If what you’re trying to do is patch a new castle.bin.lz into the game, I guess you’d dump the .3ds using Decrypt9 and the guide on the wiki, extract the ROMFS, put in your castle.bin.lz, repack it back into a ROMFS, and make a .3ds from that.

How you’d actually go about that I don’t really know. I think the HackingToolkit3DS might be a step in the right direction, though?

(Oh, also, LZ compression you shouldn’t have to worry about. The .lz at the end of the filename usually indicates that the file is compressed, and that’s the form that the game usually accepts. If, for whatever reason, you still need to do (de)compression, this worked for me for the home menu MSBTs.)