Launch settings

Every installed game has its own launch settings. To find them, open the game's Manage dialog (from the game's page, or from its right-click menu in your library) and look for the Launch settings section.

Launch options

The Launch options field lets you pass extra arguments to the game, or run it through another program.

Plain text is passed to the game as extra arguments:

--fullscreen

To run the game through a wrapper, such as a compatibility layer or a debugging tool, write %command% where the game's command should go. It expands to the game's executable along with all of its arguments:

mangohud %command%

Leading NAME=value pairs set environment variables for the game:

MANGOHUD=1 %command%

The field is parsed with shell-style quoting, so quote arguments that contain spaces. %command% must be a standalone word and can appear at most once.

Launch options only apply to games that run as native executables. They have no effect on web games.

Sandbox

The rest of the section overrides your global sandbox preferences for this game. Every setting defaults to Default, which inherits the corresponding global preference.

• Sandbox turns the sandbox on or off for this game.

On Linux, a few more settings control how the sandbox behaves:

• Sandbox type picks the backend: Auto, Bubblewrap, or Firejail. See Linux sandboxing for the differences.
• Network access in sandbox allows or blocks network access for the game.
• Allowed environment variable names is a comma or whitespace separated list of host environment variables to pass into the sandbox.

These extra settings are shown dimmed when the sandbox isn't going to be used. They still take effect if the game's manifest asks to be sandboxed.