Unreal Engine program arguments and environment variables

You can influence the runtime behavior of your game by adding program arguments and environment variables to run/debug configurations.

Go to Run | Edit Configurations. Alternatively, press Alt+Shift+F10, then 0.
In the Run/Debug Configurations dialog that opens, select a configuration where you want to pass the arguments and add the environment variables.
Type the arguments in the Optional arguments field. The arguments should be separated with spaces or new lines.
Click to expand the text field, so you can view and edit the arguments as a list.
In the Environment variables field, type the variable name and value: <name>=<value>. If you add several variables, they should be separated with semicolons.
Alternatively, click and add the variable name and value to the User environment variables list.
In the dialog that opens, you can also see the list of available system environment variables. Clear the Include system environment variables checkbox if you don't want to use the system environment variables for the selected configuration.
You can reference existing variables, including the parent environment variables, using the $VAR$ syntax. Note that such references are case-sensitive: for example, PATH=xxx:$PATH$ for Linux/macOS and Path=xxx;$Path$ for Windows.

Use command-line argument presets

Starting from version 2026.3 JetBrains Rider allows you to manage and use different command-line argument presets when launching your game.

Press Ctrl+Alt+S to open settings and then select Build, Execution, Deployment | Command Line Arguments.
Select Enable selection of command-line argument presets and save the changes.

The Preset selector appears in the main toolbar near the Run/Debug controls.

For older versions, you can use the EzArgs plugin that provides a similar functionality.

21 October 2026