26 env vars · 0 unique to this variant · scraped 28 Jul 2026
| Name | Type | Description |
|---|---|---|
| HOST_LC_ALL | unknown | Set value to a locale to override all other system locale settings for a game. This variable should be used instead of LC_ALL. |
| LICENSE | path | See the LICENSE files here, as well as the LICENSE, COPYING, etc files in each submodule and directory for details. If you distribute a built version of Proton to other users, you must adhere to the terms of these licenses. |
| PROTON_CRASH_REPORT_DIR | path | Write crash logs into this directory. Does not clean up old logs, so may eat all your disk space eventually. |
| PROTON_DISABLE_NVAPI | bool | Disable NVIDIA's NVAPI GPU support library. |
| PROTON_DXVK_D3D8 | bool | Use DXVK's d3d8.dll. |
| PROTON_FORCE_LARGE_ADDRESS_AWARE | bool | Force Wine to enable the LARGE_ADDRESS_AWARE flag for all executables. Enabled by default. |
| PROTON_HEAP_DELAY_FREE | bool | Delay freeing some memory, to work around application use-after-free bugs. |
| PROTON_HIDE_NVIDIA_GPU | bool | Force Nvidia GPUs to always be reported as AMD GPUs. Some games require this if they depend on Windows-only Nvidia driver functionality. See also DXVK's nvapiHack config, which only affects reporting from Direct3D. |
| PROTON_LOG | bool | Convenience method for dumping a useful debug log to $PROTON_LOG_DIR/steam-$APPID.log. Set to 1 to enable default logging, or set to a string to be appended to the default WINEDEBUG channels. |
| PROTON_LOG_DIR | path | Output log files into the directory specified. Defaults to your home directory. |
| PROTON_NO_D3D10 | bool | Disable d3d10.dll and dxgi.dll, for d3d10 games which can fall back to and run better with d3d9. |
| PROTON_NO_D3D11 | bool | Disable d3d11.dll, for d3d11 games which can fall back to and run better with d3d9. |
| PROTON_NO_ESYNC | bool | Do not use eventfd-based in-process synchronization primitives. |
| PROTON_NO_FSYNC | bool | Do not use futex-based in-process synchronization primitives. (Automatically disabled on systems with no FUTEX_WAIT_MULTIPLE support.) |
| PROTON_OLD_GL_STRING | bool | Set some driver overrides to limit the length of the GL extension string, for old games that crash on very long extension strings. |
| PROTON_SET_GAME_DRIVE | bool | Create an S: drive which points to the Steam Library which contains the game. |
| PROTON_USE_D9VK | bool | Note: Obsoleted in Proton 5.0. In older versions, use Vulkan-based DXVK instead of OpenGL-based wined3d for d3d9. |
| PROTON_USE_SECCOMP | bool | Note: Obsoleted in Proton 5.13. In older versions, enable seccomp-bpf filter to emulate native syscalls, required for some DRM protections to work. |
| PROTON_USE_WINED3D | bool | Use OpenGL-based wined3d instead of Vulkan-based DXVK for d3d11, d3d10, and d3d9. |
| PROTON_USE_XALIA | bool | Enable Xalia, a program that can add a gamepad UI for some keyboard/mouse interfaces, or set to 0 to disable. The default is to enable it dynamically based on window contents. |
| PROTON_WAIT_ATTACH | bool | Wait for a debugger to attach to steam.exe before launching the game process. To attach to the game process at startup, debuggers should be set to follow child processes. |
| STEAM_COMPAT_CONFIG | path | some options for known games using the STEAM_COMPAT_CONFIG variable. You can override these options using the environment variables described below. The best way to set these environment overrides for all games is by renaming user_settings.sample.py to user_settings.py and modifying it appropriately. This file is located in the Proton installation directory in your Steam library |
| VKD3D_CONFIG | unknown | Put force_bindless_texel_buffer into VKD3D_CONFIG. |
| WINE_DISABLE_VULKAN_OPWR | bool | Enable hack to disable Vulkan other process window rendering which sometimes causes issues on Wayland due to blit being one frame behind. |
| WINE_DO_NOT_CREATE_DXGI_DEVICE_MANAGER | bool | Enable hack to work around video issues in some games due to incomplete IMFDXGIDeviceManager support. |
| WINE_FULLSCREEN_INTEGER_SCALING | bool | Enable integer scaling mode, to give sharp pixels when upscaling. |