Playing in Linux

There is no official support for Oni in the Linux OS family. Nevertheless, it is still possible to run the game on Linux. The Anniversary Edition Installer can be made to run as well. If you are looking for help running Oni on the Steam Deck, see Playing on the Steam Deck for much simpler instructions.

Requirements

Wine

A compatibility layer for running Windows applications on a Linux machine. For maximum convenience, it is recommended to install Wine directly from an official repository of the given Linux distribution (it is natively supported by a wide array of distros). Wine 5.5 was found to be capable of flawlessly running Oni and the AE Installer.

1. Open a Linux terminal and search for Wine packages. You need to know what your package manager is: apk, apt-get, dnf, emerge, pacman, yum, zypp…. Tell the package manager to search for "wine" and look for a 32-bit Wine package in the results. The package might be called "wine32" or "wine.i686". Install it; the package manager may also need to install a ton of dependencies if this a fairly new Linux install.

Winetricks

A helper app for configuring various parts of Wine-created compatibility environments. In some distros, Winetricks is installed alongside Wine itself. In other distros, it needs to be installed as a separate package.

You'll also need this for the Anniversary Edition:

A legacy Java Runtime Environment offline installer for the 32-bit (AKA x86) version of Windows XP

The maximum compatible version is 7u65. An installer for 7u25 is still hosted here.

Preparing the Wine prefix

1. Open a Linux terminal and create a new Wine prefix (an instance of the Wine compatibility environment) by executing the following sequence of commands:

   export WINEARCH=win32

   export WINEPREFIX=/full/path/to/desired/location (e.g. "~/Documents/Oni" or "~/Games/Oni")

   winecfg

2. This creates a 32-bit Wine prefix in the requested folder and opens a "Wine configuration" GUI tool. In the GUI tool, under the "Applications" tab, change the target Windows version to "Windows XP". Then click on the OK button.
3. Still in the same terminal (with all the export symbols defined), run Winetricks script to execute the necessary configuration changes:

   winetricks corefonts msacm32

4. Still in the same terminal (with all the export symbols defined), use the cd command to navigate to the folder with the Java Runtime offline installer (let's assume the installer is named "jre-7u25-windows-i586.exe"). Install the JRE into the given Wine prefix:

   cd /full_path_to_the_JRE_offline_installer

   wine jre-7u25-windows-i586.exe

5. The "Oni" Wine prefix is now ready. Remember, that in order to run either Oni or the AE Installer, the path to this prefix file must be specified (exported). If it is not specified, then the Wine session will use a default prefix file, one which is probably set to represent 64-bit Windows 7 or 64-bit Windows 10 (which is quite sensible for most applications, but unfortunately not good enough for Oni).

Installing Oni

Skip to the next section if you have an existing installation of Oni.

1. Insert your Oni CD-ROM into the disc drive (if installing from the CD, 2001-style ^_^).
2. Open a Linux terminal, export the "Oni" prefix file, navigate to the folder with the contents of the mounted CD, and initiate the installation process.

   export WINEPREFIX=/full_path_to_the_folder_where_Oni_prefix_is_located

   cd /full_path_to_the_contents_of_the_Oni_installation_medium

   wine OniSetup.exe

3. During the installation process, it is recommended to NOT place the game inside the prefix file's compatibility environment folder (do not place it anywhere on the faux "C:\" drive). Instead, choose an appropriate place somewhere in your Linux machine's directory tree. The computer's native directory tree should be mapped by default as a different faux drive (usually "Z:\").
4. The game should install without problems. When GLSetup runs and offers to install OpenGL, make sure to say no.
5. DO NOT RUN THE GAME YET!!! An attempt to run an unpatched copy of Oni on a modern system is almost guaranteed to fail. The game needs to be patched via the AE Installer.

Installing AE Installer

This is a rather straightforward process which builds on an Oni installation.

1. Download the latest Windows version of the AE Installer from the Oni Mod Depot (click here).
2. Open a Linux terminal, export the "Oni" prefix, navigate to the folder with the AE Installer, and initiate the installation process.

   export WINEPREFIX=/full_path_to_the_folder_where_Oni_prefix_is_located

   cd /full_path_to_the_AE_Installer

   wine Anniversary-Edition-Setup-vXX.YY_ZZ.exe

3. During the AE Installer installation, there will be a prompt to provide Oni's installation directory. Navigate to the appropriate directory. Your Linux system's directory tree should be mapped to "/".
4. At the end of the installation, the AE Installer will be automatically executed and will attempt to fetch updates. During the fetching process, it may appear that the AE Installer has hanged. That is not true, it just does not indicate that there is work being done in the background. Be patient.

Launching AE Installer

The AE Installer will be automatically launched after it is installed. However, any other time you want to launch the AE Installer, open a Linux terminal, export the "Oni" prefix, navigate to the folder with the AEInstaller2Updater.jar file, and launch the .jar file through Wine Java Runtime Environment:

export WINEPREFIX=/full_path_to_the_folder_where_Oni_prefix_is_located

cd /full_path_to_the_AEInstaller2Updater.jar

wine start /ProgIDOpen jarfile AEInstaller2Updater.jar

Patching/modding Oni via AE Installer

Simply let the AE Installer do its magic. ^_^

Launching patched Oni

There are two possible ways to launch Oni:
A. Launch the game through the AE Installer application.
B. Open a Linux terminal, export the "Oni" prefix, navigate to the folder with the patched Oni.exe file, and launch it via Wine.

export WINEPREFIX=/full_path_to_the_folder_where_Oni_WINEPREFIX_is_located

cd /full_path_to_the_patched_Oni.exe

wine Oni.exe

Troubleshooting

Some users experience a large drop in frame rate when certain actions occur such as firing a gun. This is a sound-related bug which indicates that you didn't follow step 3 under "Preparing the Wine prefix" :-) Make sure to install msacm32 with winetricks.