Run in fullscreen mode (Unreal Engine and Source games)
Effect
Overrides a saved windowed preference. -full is the same option in Source.
Display
UniversalAdded Jun 27, 2026Last checked Sep 12, 2026
Safe
-dx11Copy
Use the DirectX 11 renderer (Unreal Engine games)
Effect
Selects DX11 as the RHI. Ignored by builds without a DX11 path.
Display
UniversalAdded Jun 27, 2026Last checked Sep 9, 2026
Safe
-highCopy
Run the game at High process priority (Source engine games)
Effect
Raises the OS scheduling priority of the game process. It does not add CPU capacity, so it helps only where something else is competing for the processor.
Performance
UniversalAdded Jun 27, 2026Last checked Sep 9, 2026
Safe
-windowedCopy
Run in windowed mode (Unreal Engine and Source games)
Effect
Unreal documents pairing it with an explicit resolution. In Source -window, -sw and -startwindowed are the same option.
Force the legacy OpenGL renderer (Unity games, legacy builds)
Effect
Windows only. Selects Unity's LEGACY OpenGL backend, not the core profile — use -force-glcore for that. Builds made with newer Unity versions may not carry the legacy backend at all, in which case this has no effect.
On the General tab, find the Launch Options field.
Type or paste the option (e.g. -windowed) into the field. To use several at once, separate them with spaces (e.g. -windowed -novid).
Close Properties. Steam saves automatically, and the option applies next time you launch the game.
To remove one, reopen the same field and delete the text. Options are game-specific; an option that helps one game may do nothing (or misbehave) in another.
Worth knowing: a launch option can break a game's rendering, reset local settings, or trip anti-cheat in multiplayer. Read the description first, add one at a time, and treat anything rated above Safe as a deliberate experiment.
