Game modding with LayeredFS

LayeredFS, a tool built into Atmosphere, allows you to (temporarily) replace a game's assets with your own, modified assets as long as you're booted into CFW.

Usage instructions

Check the section below to find your mod's folder/file structure, then install your mod accordingly.

TIP

Checking folder/file structures

• If the mod solely includes a romfs (and/or exefs folder), you will need to place that folder inside of sd:/atmosphere/contents/<title_id>/.
  • Note: The title ID folder has to be created manually in this case. This is game specific and the title ID of every game can be found on the following websites: switchbrew and nswdb.
• If the mod solely includes a contents folder, you can simply copy that folder to sd:/atmosphere/ on your microSD card and merge folders if prompted.
• If the mod has the complete folder structure set up (i.e. atmosphere/contents/<title_id>/romfs), you can simply copy the atmosphere folder (likely inside of a mod's .zip file) to the root of your microSD card and merge folders if prompted.

WARNING

Atmosphere 0.9.4 and below

Note: On Atmosphère 0.9.4 and below, contents is called titles

In the image below, you can see a Batman skin mod being used in The Legend of Zelda: Breath of the Wild. In this example, the title ID and mod installation directory would be sd:/atmosphere/contents/0100509005AF2000/.

Additional notes

The romfs folder contains modified assets in the way the game would normally read them. romfs stands for "romFileSystem", which is quite literally what the filesystem (folder and file structure) of the game you're modding consists of internally.

If you want to disable mods on launch of a game, hold the L button before launching the game and launch the game normally, L is the default button to do this. This will disable all modifications (like cheats and mods) that you have configured for your game.

While most games only require Atmosphere's LayeredFS to enable game modding, there are some games that may require more specialized setup. For example:

• Modding Super Smash Bros. requires ARCropolis and skyline. Skyline's exefs folder goes into the atmosphere/contents/01006A800016E000/ directory. ARCropolis looks for mods in the sd:/ultimate/mods directory on your microSD card.
• Modding Breath of the Wild and Tears of the Kingdom with multiple mods requires the use of BCML or UKMM (Recommended) and TKMM respectively.
• Animal Crossing: New Horizons requires some extra setup for mods to work. The folder that would normally be called romfs has to be called romFs and you'll need to create an empty file inside of atmosphere/contents/01006F8002326000/romFs/System/Resource/ called ResourceSizeTable.srsizetable. More information on this can be found on the ac-modding website.

Troubleshooting

My game crashes upon launch!

If your game crashes during launch, hold the L button to see if disabling all modifications for your game solves the issue. If so, delete the most recently added mod(s) for your game.

My mods aren't showing up in-game!

Assuming you've followed the installation instructions successfully, this is probably due to the archive bit being set on one or more folders/files on your microSD card. This is usually the result of copying files to a microSD card via a Mac. If you are experiencing this issue, try running the archive bit fixer utility via Hekate for all files.

This can be done by booting into Hekate and going to Tools > Arch bit • RCM Touch • Pkg1/2 > Fix Archive Bit.