Learn how to set Steam launch options, format multiple commands, use %command%, remove broken settings and avoid game-specific syntax mistakes.
To use Steam launch options, open Steam’s Library, right-click the game, select Properties, and enter the game’s supported command-line arguments in the Launch Options box under General. Separate multiple arguments with spaces, preserve any required hyphens or quotation marks, then close Properties and start the game normally.
For games and simulators installed through Steam, these options are saved per title and passed at every start until removed. The field itself does not edit game files, but an option can change how the game launches, which renderer it uses or what configuration it loads.
How do you set launch options in Steam?
Steam saves launch options automatically, so there is no Apply or Save button.
- Open your Library: Select the game or simulator you want to configure.
- Open Properties: Right-click the title and select Properties, or use its cog icon. On Steam Deck, select the game, open the cog menu and choose Properties.
- Select General: Find the Launch Options text box. Some games also provide a launch-mode selector in this area.
- Enter the documented command: Copy the spelling, capitalisation, punctuation and spacing exactly. Do not assume a command supported by one game works in another.
- Close Properties: Steam saves the text immediately.
- Start the game through Steam: A direct shortcut to the game’s executable may bypass Steam and its launch options.
How do you enter multiple Steam launch options?
Enter multiple ordinary game arguments on one line, separated by spaces and without commas. A generic pattern is -flag-one -setting-name "value with spaces", but those names are placeholders rather than universal Steam commands.
- Keep required prefixes such as
-,--or/; different games use different formats. - Put straight quotation marks around a value containing spaces when the game’s instructions require them.
- Do not substitute typographic “smart quotes”, which many command-line parsers fail to recognise.
- Preserve an equals sign if the documented format uses one, such as
--setting=value. - Add one option at a time when testing several changes. This makes a bad or obsolete flag easy to identify.
When is %command% required?
%command% is Steam’s placeholder for the game’s executable and its normal arguments. It is mainly needed when a wrapper, compatibility tool or Linux environment variable must appear before the game command.
A Linux or Steam Deck instruction may use a pattern such as VARIABLE=value %command%. Do not add %command% to ordinary Windows game flags unless the instructions explicitly require it, and do not copy Linux shell syntax into Windows. Our Steam Deck flight-simulator compatibility advice explains where Proton launch options fit into wider troubleshooting.
Which Steam launch options should you use?
Use only options documented for that specific game, engine, launcher or compatibility layer; Steam does not provide a universal set of performance commands.
| Purpose | What to check first |
|---|---|
| Window mode or resolution | Prefer the in-game display menu unless the game cannot reach it. Confirm the exact argument and value format. |
| Graphics renderer or API | Use only a renderer the game officially supports. An incompatible choice can produce a black screen or startup failure. |
| Logging or safe mode | Check where the game writes its log and whether safe mode changes or resets other settings. |
| Skipping a launcher or intro video | Confirm that the game executable or its launcher recognises the flag; many third-party launchers discard unknown arguments. |
| Linux, Proton or wrapper tools | Follow the required %command% placement and operating-system syntax exactly. |
Good sources are the game’s own manual, readme file, developer instructions or a diagnostic message that names the required argument. Lists copied from another game can contain harmless no-ops, obsolete engine flags or commands that prevent startup.
How do you remove or reset Steam launch options?
Return to Properties > General, delete everything from the Launch Options box and close the window. Launch the game again to test its default behaviour.
Clear the field manually rather than assuming file verification or reinstalling the game will remove it. Steam stores this setting separately from most installed game files, so verifying those files does not normally reset custom launch arguments.
Why will a game not launch after adding an option?
An unsupported argument, malformed quotation mark, incompatible renderer or incorrectly placed %command% can stop a Steam game before its main window appears.
- Clear the entire field and launch once with no custom options.
- Retype the option manually to eliminate smart quotes, hidden characters and copied punctuation.
- Add options individually until the failure returns.
- Check for a separate launcher that may consume or discard Steam’s arguments.
- Verify the installed files only if the game still fails with an empty Launch Options box.
Old arguments can also become invalid after a game or launcher update. If clearing the box does not restore a railway simulator, our Train Simulator Classic startup checklist covers launch settings and the other common causes of a failed start.
Do Steam launch options improve game performance?
There is no generic launch-option pack that makes every Steam game faster. Commands claiming to force high priority, assign processor threads or allocate extra memory do nothing unless that particular game recognises them, and forced settings can make performance or stability worse.
A documented renderer or diagnostic option can help isolate a real problem, but use the in-game settings for routine tuning. For example, our FSX: Steam Edition slow-start troubleshooting covers the wider checks to make instead of relying on unverified command packs.