Breath of the Wild uses a very flexible, custom game engine. Many aspects of the game are not hardcoded and are instead configured by a large amount of files. To edit these files, a certain number of tools are required.
Resource system when adding new resources or making existing files larger because of how the game works internally
SARC for archives since many resource files are packed
Tools
In general, there are several tools you can use for a given file format. This guide will only mention the recommended tools; a more complete list of utils can be found in the article for each file format.
Some are unfortunately Windows-only, but many — especially the newer ones — are cross platform and work on Windows, macOS and Linux (with Linux even being the best supported platform for some tools).
Common requirements
Many of the tools for these formats require Python 3.6+ (64 bit version) to be installed.
On Linux, Python 3 is almost surely already installed. Just make sure you have a recent enough version (3.6+). Ubuntu 16.04 and Debian stretch are too old; the latest Ubuntu LTS (18.04) and rolling distros such as Arch and Debian sid have 3.6+ in their repos.
On Windows, follow the below instructions for installing Python:
Uninstall any existing Python version to avoid conflicts.
Incomplete parameter type support: Esoteric parameter types (buffers) are not fully supported: currently the tool can display files that use buffers correctly but cannot convert them back to AAMP.
Download the tool from GitHub (note: builds are only provided for Windows).
Non-root parameter lists: Parameter lists are not handled correctly at this moment, which causes files (baiprogs for instance) that rely on nested lists to have a strange structure in their XML representation.
Parameter names with leading numbers: Nintendo sometimes starts parameter structure names with numbers. aamptool converts structures into XML tags; however leading numbers in tag names are explicitly disallowed by the XML specification. As a result files with such nodes cannot be converted back from XML into AAMP correctly. aamptool will either crash or fail to convert the affected parameter nodes.
Incomplete parameter type support: Esoteric parameter types such as curves and buffers are not supported. This is problematic because a conversion into XML will only keep one byte of the original data, leading to data loss when converting back to AAMP.
Simply download the latest compiled release from GitHub, unzip, and launch the exe. Note that the latest release has an old date, but it is current, as it automatically rebuilds with each commit.
Ensure you have a 64 bit version of Python 3.7+ before continuing. Windows users must also install the latest x64 Visual C++ redistributable. You will not be able to install or launch Wild Bits otherwise. See Help:Setting_up_tools.
(Optional) For best results on Windows, install cefpython3. [CLI help]
Wii U only: Only works with big endian files and unable to handle Switch (little endian) documents.
Incomplete support for newer node types: Newer node types (0xd4, 0xd5, 0xd6, 0xff) are not supported. In practice, this is not an issue for Breath of the Wild as these are not known to be used in the game.
Simply download the latest compiled release from GitHub, unzip, and launch the exe. Note that the latest release has an old date, but it is current, as it automatically rebuilds with each commit.
Ensure you have a 64 bit version of Python 3.7+ before continuing. Windows users must also install the latest x64 Visual C++ redistributable. You will not be able to install or launch Wild Bits otherwise. See Help:Setting_up_tools.
(Optional) For best results on Windows, install cefpython3. [CLI help]
Size calculation for complex resources: rstb is currently unable to calculate file sizes for complex resource classes (see Resource system for more information). The CLI will suggest deleting entries if it detects that this is the case.
Simply download the latest compiled release from GitHub, unzip, and launch the exe. Note that the latest release has an old date, but it is current, as it automatically rebuilds with each commit.
Ensure you have a 64 bit version of Python 3.7+ before continuing. Windows users must also install the latest x64 Visual C++ redistributable. You will not be able to install or launch Wild Bits otherwise. See Help:Setting_up_tools.
(Optional) For best results on Windows, install cefpython3. [CLI help]
Unnecessary padding for BotW: SARC Tool may add unnecessary padding when archives are repacked, meaning generated archives may end up larger than the original even if no file size has increased inside the SARC. The game will fail to load it unless you fix the Resource system.
Simply download the latest compiled release from GitHub, unzip, and launch the exe. Note that the latest release has an old date, but it is current, as it automatically rebuilds with each commit.
Ensure you have a 64 bit version of Python 3.7+ before continuing. Windows users must also install the latest x64 Visual C++ redistributable. You will not be able to install or launch Wild Bits otherwise. See Help:Setting_up_tools.
(Optional) For best results on Windows, install cefpython3. [CLI help]
To reverse engineer the game executable, it is strongly recommended to have a copy of IDA Pro 7.0+ because the main executable is fairly large and IDA is as of September 2018 the only serious option for analysing such binaries. It is also the only tool with a usable decompiler for AArch64 (Switch).
To get a copy of an IDC for Switch 1.5.0, ping leoetlino.
